Effects of Transcranial Alternating Current Stimulation (tACS) at Gamma Band Frequencies on Memory Recall and Sleep in Healthy Elderly Participants
Phase: NA
Conditions: Transcranial Alternating Current Stimulation, Aging, Cognitive Decline, Memory, Sleep
Sponsor: University of North Carolina, Chapel Hill

 
Effects of Transcranial Alternating Current Stimulation (tACS) 
on Memory Recall and Sleep-EEG in Healthy Elderly Participants 
 
 
 
NCT number NCT05907707 
Document Date 08/15/2023 
 

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Master Protocol Document 
 
Title 
Effects of Transcranial Alternating Current Stimulation (tACS) 
on Memory Recall and Sleep-EEG in Healthy Elderly Participants  
Sub-Title 
 
A Double-Blind, Controlled Cross-Over Pilot Study 
Principal Investigator 
 
Flavio Frohlich, PhD, Carolina Center for Neurostimulation, Department of 
Psychiatry, UNC School of Medicine, Chapel Hill, NC 
(also serving in the role of statistical expert) 
Co-Investigators 
 
Andrea Seiler, MD, Carolina Center for Neurostimulation, Department of 
Psychiatry, UNC School of Medicine, Chapel Hill, NC 
 
 
 
Research Sites 
University of North Carolina at Chapel Hill 
Version Number  1.4 08/15/2023    
 
 
 
 
I have read, understood, and approved this version of the protocol.    
 
Principal Investigator:      
 
 
 
 
Date:  
______________ 
 
 
 
 
Statement of Confidentiality and Nondisclosure     This document is a confidential communication.  Acceptance of this document 
constitutes agreement by the recipient that no unpublished information contained herein will be published or disclosed without 
prior written approval of the Principal Investigator or other participating study leadership, except that this document may be 
disclosed in any medium to appropriate investigators, Institutional Review Boards, Scientific Review Committees, and others who 
are directly involved in the study specified herein under the condition that they keep the information confidential. 
 
 

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Table of Version Changes 
 
Previous 
Version No. 
Affected 
Sections 
Summary of the Changes 
to the Protocol 
Reason for Changes 
1.0 
1. SYNOPSIS 
2. AIMS  
3. STUDY 
DESIGN 
4. ELIGIBILITY 
CRITERIA 
5. TREATMENT 
DESIGN 
6. SCHEDULE 
(STUDY VISITS) 
 
1. CHANGED AIMS (ADDED ASSOCIATIVE MEMORY, 
ADAPTED EVERYTHING ACCORDING TO 
CLINICALTRIALS.GOV), CHANGED OUTCOMES AND 
STATISTICAL PLAN ACCORDINGLY; CHANGED EXCLUSION 
(NO AD8 DUE TO ALREADY HIGH COUNT OF 
QUESTIONNAIRES) 
2. CHANGED AIMS ACCORDING TO 
CLINICALTRIALS.GOV. MADE SLEEP MORE CONCRETE 
(ONLY SPINDLES AND SLOW WAVES ARE OUTCOMES); 
OTHER NEUROPSYCHOLOGICAL OUTCOMES THAN 
MEMORY SECONDARY OUTCOMES (DÖRTHE THINKS IT 
IS OKAY) 
3. ADDED TELEPHONE CONTACTS EXPLICITLY; CHANGED 
ELECTRODES TO F7/P7 AND F8/P8  
4. NO AD8  
5. ADDED WORD ASSOCIATION TEST 
6. ADDED ASSOCIATIVE MEMORY, CHANGED QUESTION 
ABOUT ALCOHOL AND PSYCHOTROPIC 
SUBSTANCES/DRUGS FOR FOLLOW-UP VISITS (NOT LAST 
3M, BUT LAST 24H), RVDLT ONLY DURING VISIT 2, 
AND RECALL IMMEDIATELY AFTER ENCODING (TO WIN 
TIME FOR ANALYSIS OF Y-FREQUENCY)  
 
1.1 
1. 
MEASUREMENT 
DESIGN, 
ENROLLMENT, 
STUDY DESIGN  
2. 
EVERYWHERE 
3. SECTION 7 
1. RVDLT FOR Y-FREQUENCY ON VISIT 1 INSTEAD OF 
VISIT 2 (TO HAVE MORE TIME FOR ANALYSIS) 
2. CHANGED PHONEMATIC/VERBAL FLUENCY TO 
LETTER FLUENCY (TO HAVE THE SAME VOCABULARY  
3. CHANGED TIMEPOINT OF VISIT 5 FROM DAY 5-9 
AFTER STIMULATION TO DAY 6-9 AFTER STIMULATION 
(VISIT 4 AND 5 NOT ON THE SAME DAY, AND VISIT 4 
ALREADY ON DAY 5 AFTER STIMULATION) 
 
1.2 
 
1. 4 HOURS OF SLEEP EEG IS NOT AN EXCLUSION 
CRITERIA (WE WANT TO FIND OUT HOW MANY MANAGE 
TO DO IT)  
2. NOT SHAM, BUT CONTROL FREQUENCY (21 HZ – 10 
HZ WORSENS AUDITORY ATTENTION, 20 HZ IS 
HARMONIC; ALSO: CLOSER TO 40 HZ, THEREFORE 
SIMILAR SIDE EFFECTS, BUT NOT YET GAMMA). TEXT 
FROM MODIFICATION: WE ARE NOW TIGHTENING THE 
SCIENTIFIC CONTRAST SUCH THAT WE CAN DRAW 
CONCLUSIONS ABOUT THE EFFECT OF A SPECIFIC 
STIMULATION FREQUENCY, 
 

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WHEREAS OUR PREVIOUS DESIGN ONLY ALLOWED TO 
DRAW 
CONCLUSIONS 
ABOUT 
THE 
EFFECT 
OF 
STIMULATION IN 
GENERAL. THUS, WE NOW USE A CONTROL FREQUENCY 
OF 21HZ INSTEAD OF THE ACTIVE SHAM STIMULATION. 
3. TACS AMPLITUDE IS INDIVIDUALIZED (SAME 
AMPLITUDE FOR BOTH CONDITIONS; HAS TO BE 
SUPPORTED FOR 1H, THRESHOLDING FOR 21 AND 40 
HZ, LOWER AMPLITUDE IS TAKEN)  
4. NO 
INDIVIDUALIZED GAMMA, 
BECAUSE 
NO 
CLEAR/SINGLE PEAK DURING RVDLT ACCORDING TO 
JIMIN’S ANALYSIS 
5. ELECTRODE POSITIONING FOR LEAST SIDE EFFECTS: 
T7/8, P7/8 
6. ACTIGRAPHY ADDED TO SEE IF STIMULATION 
CHANGES 
ACTIVITY 
PATTERN. 
TEXT 
FROM 
MODIFICATION: 
ACTIGRAPHY: 
WEARING 
AN 
ACTIGRAPHY WRISTBAND. PARTICIPANTS ARE ASKED TO 
WEAR A WRIST-WORN ACCELEROMETER FROM VISIT 1 
TO VISIT 6. THE DEVICE RECORDS REST AND ACTIVITY 
PHASES BY MEANS OF AN ACCELEROMETER, THUS 
ALLOWING CONCLUSIONS TO BE DRAWN ABOUT THE 
SLEEP-WAKE RHYTHM. WE PURSUE AN ADDITIONAL 
EXPLORATORY GOAL WITH ADDING ACTIGRAPHY: 
SUPPLEMENTAL DATA IN ADDITION TO THE ALREADY 
APPROVED 
EEG 
WITH 
REGARDS 
TO 
THE 
NEUROPHYSIOLOGY OF MEMORY CONSOLIDATION SLEEP 
AFTER 40 HZ STIMULATION (COMPARED TO 21HZ AND 
COMPARED TO NIGHTS WITHOUT STIMULATION IN 
BETWEEN): THE DEVICE IS WORN ON THE WRIST (LIKE A 
WATCH), IT IS LIGHTWEIGHT, AND IT DOES NOT NEED TO 
BE RECHARGED DURING THE SCHEDULED WEARING 
PERIOD. 
7. 
MOTOR 
THRESHOLDING 
(TEXT 
FROM 
MODIFICATION): SINCE THE ORIGINAL DESIGN OF THE 
STUDY, NEW EVIDENCE SUGGESTS AN INTERESTING 
RELATIONSHIP BETWEEN THE EFFECT OF TACS AND 
BRAIN EXCITABILITY MEASURED WITH SINGLE PULSE 
TMS. WE WILL THEREFORE MEASURE CORTICAL 
EXCITABILITY BY PERFORMING MOTOR THRESHOLDING 
USING SINGLE PULSE TMS (TRANSCRANIAL MAGNETIC 
STIMULATION) DURING VISIT 2. THE PROCEDURE TAKES 
ONLY A FEW MINUTES, AND ONLY SINGLE PULSES WILL BE 
APPLIED UNTIL A MOTOR RESPONSE RESULTS AT THE 
HAND (=5 OUT OF 10 EVOKED POTENTIALS OF FIRST 
DORSAL INTEROSSEUS MUSCLE =50ΜV PEAK-TO-PEAK). 
8. (PLANNING) PREGNANCY IS REASON FOR EXCLUSION 

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1.3 
 
ADAPTED OUTCOMES TO THE VERSION SUBMITTED TO 
THE IRB (=ADDING AIM 8). 
 
CHANGING TYPOS IN THE SCHEDULE.  
 
1.4 
 
- EXCLUSION CRITERIA: PSQI > 5 (INSTEAD OF >6) 
- SESSIONS: 8AM-12PM, 12PM-6PM 
 
 
 
 
 

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Table of Contents 
Table of Version Changes ..................................................................................................................................... 2 
Statement of Compliance ..................................................................................................................................... 7 
Table of Abbreviations ......................................................................................................................................... 8 
1. 
Protocol Synopsis ..................................................................................................................................... 9 
2. 
Introduction ........................................................................................................................................... 12 
2.1. 
Background Information .................................................................................................................... 12 
2.2. 
Scientific Rationale ............................................................................................................................. 13 
3. 
Specific Aims .......................................................................................................................................... 14 
3.1. 
Aim 1 .................................................................................................................................................. 14 
3.2. 
Aim 2 .................................................................................................................................................. 14 
3.3. 
Aim 3 .................................................................................................................................................. 14 
3.4. 
Aim 4 .................................................................................................................................................. 14 
3.5. 
Aim 5 .................................................................................................................................................. 14 
3.6. 
Aim 6 .................................................................................................................................................. 14 
4. 
Study Design........................................................................................................................................... 17 
4.1. 
Treatment Design ............................................................................................................................... 17 
4.2. 
Experimental Design ........................................................................................................................... 18 
4.3. 
Measurement Design ......................................................................................................................... 18 
5. 
Study Participants .................................................................................................................................. 22 
5.1. 
Numbers of Participants ..................................................................................................................... 22 
5.2. 
Eligibility Criteria ................................................................................................................................ 22 
5.3. 
Enrollment/Selection Strategies ........................................................................................................ 23 
5.4. 
Strategies for Retention ..................................................................................................................... 23 
5.5. 
Matching and Stratification ................................................................................................................ 23 
5.6. 
Randomization  and  Concealment .................................................................................................... 24 
5.7. 
Blinding ............................................................................................................................................... 24 
6. 
Treatment Design: Procedures .............................................................................................................. 25 
7. 
Schedule of Activities and Procedures .................................................................................................. 27 
7.1. 
Table of Events ................................................................................................................................... 27 
7.2. 
Screening ............................................................................................................................................ 28 
7.3. 
Enrollment .......................................................................................................................................... 29 
7.4. 
Study Visits ......................................................................................................................................... 29 
7.5. 
Early Discontinuations ........................................................................................................................ 31 
7.6. 
Enrollees May Drop Out ..................................................................................................................... 32 
8. Statistical Analysis Plans ................................................................................................................................ 33 
8.1. Strategies that Apply to all the Aims ....................................................................................................... 33 
8.2 Sample Description ................................................................................................................................... 33 

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8.3 Aim-Specific Plans ..................................................................................................................................... 33 
8.4 Planned Interim Analyses ......................................................................................................................... 34 
9. Sample Size Rationale .................................................................................................................................... 35 
10. Data Capture and Database Management .................................................................................................. 35 
10.1. Software for Data Capture ..................................................................................................................... 35 
10.2. Responsibilities for Data Capture and Database Management ............................................................. 35 
10.3. Study Records Retention ....................................................................................................................... 35 
11. Collection and Management of Tissue Specimens ...................................................................................... 36 
Not applicable. ................................................................................................................................................ 36 
12. Safety Monitoring and Management .......................................................................................................... 36 
12.1. Risk / Benefit Assessment ...................................................................................................................... 36 
12.2. Assessment of Safety ............................................................................................................................. 37 
12.3. Unanticipated Problems, Adverse Events, Serious Adverse Events ...................................................... 37 
12.4. Safety Monitoring .................................................................................................................................. 40 
12.5. Study Suspension / Early Termination of the Study .............................................................................. 40 
13. Regulatory, Ethical, and Study Oversight Specifications ............................................................................ 40 
13.1. Informed Consent Process ..................................................................................................................... 40 
13.2. Study Discontinuation and Closure ........................................................................................................ 41 
13.3. Confidentiality and Privacy .................................................................................................................... 41 
13.4. Future Use of Stored Specimens and Data ............................................................................................ 42 
13.5. Key Roles and Study Governance .......................................................................................................... 42 
13.6. Safety Oversight ..................................................................................................................................... 42 
13.7. Clinical Monitoring Plan (CMP) .............................................................................................................. 42 
13.8. Quality Assurance and Quality Control .................................................................................................. 43 
13.9. Protocol Deviations ................................................................................................................................ 43 
13.10. Publication and Data Sharing Policy .................................................................................................... 43 
13.11. Conflict of Interest Policy ..................................................................................................................... 43 
14.Additional Considerations............................................................................................................................. 44 
15. References .................................................................................................................................................... 44 
 
 
 
 
 
 

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Statement of Compliance 
This study will be conducted as specified in the protocol and in accordance with the International Conference on 
Harmonisation Guidelines for Good Clinical Practice (ICH E6) and the Code of Federal Regulations on the Protection 
of Human Subjects (45 CFR Part 46).  
The protocol, informed consent form(s), recruitment materials, and all participant materials will be submitted to 
the Institutional Review Board (IRB) for review and approval.  Approval of both the protocol and the consent form 
must be obtained before any participant is enrolled.  Any amendment to the protocol will require review and 
approval by the IRB before the changes are implemented to the study.  In addition, all changes to the consent form 
will be IRB-approved; a determination will be made regarding whether a new consent needs to be obtained from 
participants who provided consent, using a previously approved consent form. 
If required by the IRB, the master protocol document, informed consent form(s), recruitment materials, and all 
participant materials will be submitted to the Scientific Review Committee (SRC) prior to IRB review 
(research.unc.edu/clinical-trials/src). 
The statistical analysis plans will be consistent with guidance in CONSORT Statement [1] or STROBE Statement [2], 
ICMJE recommendations [3], the 2016 and 2019 statements of the American Statistical Association [4,5], and 
recommendations in Nature [6,7].*  
All personnel involved in the conduct of this study have completed human participants protection training. 
 
 
 
 
 
 
 
 
 
 
*  [1]   www.consort-statement.org  
   [2]  www.strobe-statement.org  
   [3]  www.icmje.org  
   [4]  Wasserstein RL, et al. (2016), The ASA's Statement on p-Values, The American Statistician, 70:2, 129-133  
   [5]  Wasserstein RL, et al. (2019), Moving to a World Beyond p < 0.05, The American Statistician, 73:sup1, 1-19  
   [6]  Amrhein, et al. (2019) Scientists rise up against statistical significance, Nature 567, 305-307  
   [7]  Editorial (2019) It’s time to talk about ditching statistical significance: Looking beyond a much used and abused measure 
          would make science harder, but better. Nature 567, 283-283. 

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Table of Abbreviations 
AE / SAE 
adverse event / serious adverse event 
CFR 
U.S. Code of Federal Regulations (www.eCFR.gov) 
CI 
confidence interval 
CIOMS 
Council for International Organizations of Medical Sciences (cioms.ch) 
CoC 
certificate of confidentiality 
CONSORT 
Consolidated Standards of Reporting Trials (www.consort-statement.org) 
CRF 
case report form 
CRO 
contract research organization 
CSCC 
UNC Collaborative Studies Coordinating Center  (sites.cscc.unc.edu/cscc) 
CT.gov 
ClinicalTrials.gov website 
DCC 
data coordinating center 
DSMB 
data and safety monitoring board 
eCRF 
electronic case report form 
eCTD 
electronic common technical document 
EEG 
Electroencephalography/electroencephalogram 
DOH! 
I need to delete this example term (and others not used in this protocol) from this table 
FDA 
U.S. Food and Drug Administration   (www.fda.gov) 
GCP 
good clinical practice 
HIPAA 
U.S. Health Insurance Portability and Accountability Act   (www.hhs.gov/hipaa) 
ICF 
informed consent form 
ICH 
International Council for Harmonization   (www.ich.org) 
ICMJE 
International Committee of Medical Journal Editors   (www.icmje.org) 
IDE 
investigational device exemption 
IDS 
UNC Investigational Drug Services  (uncids.web.unc.edu) 
IND 
investigational new drug application 
IRB 
institutional review board 
MAR 
missing at random criterion 
MCAR 
missing completely at random criterion 
MNAR 
missing not at random criterion 
MICE 
multiple imputation by chained equations 
MOP 
manual of procedures 
MPD 
master protocol document 
N 
number of enrolled participants 
NDA 
new drug application 
OCT 
UNC Office of Clinical Trials (research.unc.edu/clinical-trials) 
OHRP 
Office for Human Research Protections 
PHI 
protected health information 
PI 
principal investigator 
PRC 
UNC Oncology Protocol Review Committee   (UNClineberger.org/protocolreview) 
QA 
quality assurance 
RCT 
randomized controlled trial 
REDCap 
Research Electronic Data Capture system 
SD 
standard deviation 
SE 
standard error 
SOP 
standard operating procedures 
SRC 
UNC Scientific Review Committee   (research.unc.edu/clinical-trials/src) 
STROBE 
Strengthening Reporting of Observational Studies in Epidemiology   (www.strobe-statement.org) 
tACS 
Transcranial Alternating Current Stimulation 
TraCS 
N.C. Translational and Clinical Sciences Institute   (tracs.unc.edu) 
UNC 
The University of North Carolina 
UNCH 
UNC Hospitals 
 

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1. Protocol Synopsis 
Title 
Effects of Transcranial Alternating Current Stimulation (tACS) 
on Memory Recall and Sleep-EEG in Healthy Elderly Participants 
(SUPERCHARGE) 
Study Description 
The purpose of this clinical trial is to investigate the feasibility and efficacy 
of non-invasive transcranial alternating current stimulation (tACS) at 
gamma frequency in enhancing memory recall and modulating sleep 
network dynamics measured by at-home electroencephalography (EEG) 
in healthy elderly people. Eligible participants will first collect sleep EEG 
at home for one night to acclimate to the data collection during sleep. 
Participants are then randomized into first undergoing either gamma-
tACS or controlcontrol  tACS. Stimulation is administered in the lab during 
a cognitive testing battery that includes memorizing items. After a night 
of sleep with EEG at home, participants return to the lab the following day 
to measure memory recall. Memory recall is tested again by telephone 
five days later. This sequence of encoding during stimulation in the lab, 
sleep EEG at home for one night, and memory recall is then repeated for 
the other stimulation condition about a week later. An acigraphy watch 
(accelerometer) is worn during the whole study period.  
Specific Aims 
(objectives) 
Aim 1: To establish acceptability of cognitive testing during tACS in 
healthy elderly participants. 
Aim 2: To investigate the effect of a single session of gamma-tACS 
(compared to control tACS) on verbal memory (a) and associative memory 
(b) performance during stimulation, on the day after stimulation and after 
five days. 
Aim 3: To establish feasibility of at-home use of a single-channel EEG 
device during one night (a) and acceptability during three nights (b).  
Aim 4: To investigate the effect of a single session of gamma-tACS 
(compared to control tACS) on the amount of sleep spindles (a) and slow 
wave sleep (b) occurring during the night after the intervention. 
Aim 5: To see if there is a correlation between memory recall 
performance and sleep EEG features (especially spindles, slow waves). 
Aim 6: To investigate the effect of a single session of gamma-tACS 
(compared to control tACS) on a letter fluency task (a), executive 
functioning (Stroop Test (b), Trail Making Test (c)) and attention 
(Attentional Performance, TAP (d)). 
Aim 7: To see if the motor activity pattern (measured by actigraphy) 
changes after stimulation/type of stimulation.  
Aim 8: To investigate if there is a relationship between the brain 
excitability derived from the subjective effect of tACS and the motor 
threshold measured by TMS. 
Target Population 
Inclusion Criteria  
• 
>50 years old 
 
Exclusion Criteria 
• 
Implanted device or metal in head (including cochlear implant 
or other hearing aid), cardiac pacemaker or any other 
powered medical device 
• 
Known neurological disease from history (epilepsy, sleep 
disorder (insomnia, sleep apnea, restless legs syndrome, 

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parasomnia), stroke or transitory ischemic attack, cognitive 
impairment, neurodegenerative disease (for example 
Alzheimer’s disease, Parkinson’s disease or amyotrophic 
lateral sclerosis), immune-mediated disease of the central 
nervous system, chronic infectious brain disease, brain 
tumor, traumatic brain injury with loss of consciousness 
and/or intracranial bleeding, chronic pain with the need for 
daily analgesic use) 
• 
Positive screening for epilepsy (questionnaire) 
• 
Pathological Montreal Cognitive Assessment (MoCA <26/30 
points)  
• 
Brain surgery in the past (lifetime) 
• 
Known psychiatric disorder from history (schizophrenia 
(lifetime), obsessive compulsive disorder (OCD; lifetime), 
borderline personality disorder (lifetime), anxiety disorder 
(lifetime), bipolar disorder (lifetime), psychosis (lifetime), 
eating disorder (lifetime), depression (within the last three 
months) 
• 
Positive screening for anxiety disorder (GAD-7 ≥10/21 points) 
or positive screening for depression (PHQ-9 ≥5/27 points)   
• 
Known other relevant medical condition from history 
(moderate to severe chronic obstructive pulmonary disease 
(COPD), abnormal kidney function (defined as estimated 
Glomerular Filtration Rate <60ml/min), current liver disease 
(defined as hepatitis and/or liver cirrhosis), cancer, diabetes 
mellitus, cardiac disease (heart failure, myocardial infarct, 
atrial fibrillation and revascularization – all within the last 
three months) 
• 
Working in night shifts or going to bed after midnight on 3 or 
more nights per week 
• 
Positive screening for sleep disorder (PSQI >5/21 points) 
• 
Psychotropic treatment or illegal drugs (including cannabis) 
within the last three months 
• 
Indication for alcohol use disorder: AUDIT score (Alcohol Use 
Disorders Identification Test; screening for unhealthy alcohol 
use) ≥7 for females and for males ≥ 65 years or ≥8 for males 
<65 years 
• 
Not willing to abstain alcohol at least 24 hours before each 
study visit 
• 
Women who want to become pregnant, are pregnant, plant to 
seek or are seeking fertility treatment 
 
Reason for immediate early termination of participation 
• 
Epileptiform activity in 128-channel EEG on the first day 
 
Numbers of Enrollees 
This pilot study requires n = 28 participants who complete all aspects of 
the protocol. Participants are recruited and enrolled until this target is 
reached. We anticipate screening up to 100 participants and enrolling up 
to 50 participants.  

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Intervention 
This is a single-center prospective interventional control controlled cross-
over pilot study.  
The intervention consists of the application of tACS stimulation in the 
gamma-frequency range during approximately one hour of cognitive 
testing. 
Outcome Measures 
Aim 1: 
 Cognitive testing during tACS completed in >80% of participants. 
Aim 2:  
Participants will memorize 15 words ("Rey Verbal Learning Test", (a)) and 
8 word-pairs (associative verbal memory, (b)) during gamma-tACS and 
control tACS. They will be required to recall the words after a short delay 
on the same day, on the day after and after 5 days ("ultra-delayed recall"). 
The number of correctly remembered words (a) and word-pairs (b) will be 
recorded. 
Aim 3: 
Feasibility (a) will be considered feasible if the device has been worn for 
at least 4 hours during the first night for >/= 80% of participants. 
Acceptability (b) will be considered as given if the device has been worn 
for at least 4 hours during each of the three nights in >/=80% of 
participants. 
Aim 4:  
Amount of sleep spindles (a) and slow wave sleep (b) during sleep 
recording. 
Aim 5: 
Exploration of correlation between memory recall performance and sleep 
EEG features (especially spindles, slow waves). Difference in recall scores 
(verum versus sham tACS) will be correlated with differences in sleep EEG 
features (verum versus sham tACS). 
Aim 6: 
For (a) the number of correct words, of perseverations and of rule 
breaks will be calculated. For (b) and (c) time for test completion and 
errors will be calculated. For (d) percentile ranks for the following 
subtests will be calculated: Alertness, Go/NoGo, Divided Attention, 
Visual Scanning. 
Aim 7:  
Exploration of correlation between amount of motor activity/inactivity 
phases (measured by actigraphy watch) and stimulation versus no 
stimulation as well as gamma- versus control stimulation.  
Aim 8: 
Exploration of correlation between the TMS motor threshold and the 
maximal tolerated amplitude (according to the subjective symptoms) for 
tACS. 
Statistical Analysis Plans  
for Each Aim  
Aim 1: Proportion (percentage and 95% confidence interval) of 
participants with completed cognitive testing during stimulation study 
session.  
Aim 2: 
Comparison of memory and associative testing after stimulation and 
sham on individual and group level using ANCOVA. 
Aim 3: 
Proportion (percentage, 95% confidence interval) of participants with at 
least four hours of EEG-data in the first night (a).Proportion (percentage, 

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95% confidence interval) of participants who successfully collected at 
least four hours of EEG for all three study nights (b). 
Aim 4: 
Comparison of sleep spindles (a) and slow wave sleep (b) derived from 
sleep EEG for verum versus control tACS using ANCOVA. 
Aim 5: 
Exploratory investigation of correlations (Pearson’s) between stimulation 
induced changes in memory recall performance and sleep EEG features. 
Aim 6: 
Comparison of test results after stimulation and sham on individual and 
group level using ANCOVA. 
Aim 7: Exploratoy investigation of correlations (Pearson’s) between 
changes in motor activity pattern before and after stimulation.  
Aim 8: Exploratory investigation of a correlation (Pearson’s) between the 
level of the TMS motor threshold and the tolerated tACS level (lower level 
from 21 Hz and 40 Hz, based on subjective symptoms).  
Study Duration 
1 year 
Participation Duration 
2 weeks 
Enrollment Duration 
6 months 
 
 
 
2. Introduction 
2.1.  Background Information 
The decline of cognitive functions, especially memory, is a common complaint, both during the normal ageing 
process and in dementia (1): More than half of the population will probably face such symptoms in their second 
half of life.  
 
Parallel to cognition, sleep architecture changes in older age, including a reduction of slow wave sleep (for a review 
see (2)). Given the importance of sleep for the consolidation of memory (for a review see (3) and (4)) and its role in 
reducing cellular waste (including amyloid, the pathological hallmark of Alzheimer’s disease) via the glymphatic 
system (5), it seems plausible that a deterioration of sleep in older individuals partly explains a worsening of memory 
functions.  
 
Despite the importance of the problem, there is still a lack of effective measures against cognitive decline in ageing 
individuals.  
 
However, advances in neuroscience within the last few years have given us an increasingly detailed understanding 
of the oscillations of brain activity in neural circuitries associated with cognitive processes, offering possibilities of 
influencing them.  
 
Transcranial alternating current stimulation (tACS) is an established, safe way to non-invasively modulate 
oscillations in neuronal networks and thus potentially restore and improve the associated cognitive functions (for a 

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recent review of applying tACS to improve cognition in various contexts see (6), for tACS to improve memory in 
healthy adults see (7)).  
 
 
 
2.2.  Scientific Rationale 
This controlled cross-over pilot study will be used to prepare for a full-scale RCT in patients with mild cognitive 
impairment by investigating feasibility as well as acceptability and adherence of the study procedures in a sample 
of n=28 healthy elderly adults. Any effect on memory performance and sleep EEG will be documented but is not a 
requirement for the development of an RCT. We include people over 50 years of age because memory problems 
and neurodegenerative diseases (specifically Alzheimer's Disease) occur in the second half of life. The exclusion 
criteria are designed to ensure that people are not cognitively impaired by a disease of the brain or other 
impairment of bodily functions. In addition, we exclude contraindications to tACS.    
The pilot study serves as a basis for the application of the technique in specific patient groups, in particular those 
with mild cognitive impairment. 
 
 

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3. Specific Aims 
 
3.1. Aim 1 
To establish acceptability of cognitive testing during tACS in healthy elderly particpants. The threshold is set 
to 80% of participants.  
 
3.2. Aim 2 
Evaluation of an effect of a single session of gamma-tACS on memory (a) and associative memory (b) 
performance compared with control tACS. The estimand of interest is the comparison of the individual 
results of the memory tests at the individual and at the group level (paired t-test or a non-parametric test, 
respectively). for delayed (immediately after stimulation) and ultra-delayed recall (after a night of sleep as 
well as after 5 days).  
 
3.3. Aim 3 
Feasibility (a) and acceptability (b) of an ambulatory single-channel EEG device. The estimands of interest 
are the proportion of participants with at least four hours of recording in the first night (a) and the 
proportion of participants with three nights of at least 4 hours of EEG data (b). 
 
3.4. Aim 4 
The comparison of specific sleep EEG features, i.e. sleep spindles (a) and slow wave sleep (b), which are 
both prominently associated with cognitive functioning, especially memory processes, after each 
stimulation condition. Comparison will be on individual and on group level (via t-test or a non-parametric 
test, respectively).  
 
3.5. Aim 5 
To investigate whether there is a correlation between the effects of tACS (versus control control tACS) on 
memory recall and memory-associated sleep EEG features (especially amount of sleep spindles and slow 
wave sleep) on an exploratory level.  
 
3.6. Aim 6 
To investigate the effect of a single session of gamma-tACS (compared to control control tACS) on different 
cognitive functions, i.e. a letter fluency task (a), executive functioning (Stroop Test (b), Trail Making Test (c)) 
and attention (Attentional Performance, TAP (d)). These tests will be performed during stimulation and on 
the day after stimulation, and comparison will be calculated on the individual and on the group level (paired 
t-test or non-parametric test, respectively). For (a) the number of correct words, of perseverations and of 
rule breaks will be calculated. For (b) and (c) time for test completion and errors will be calculated. For (d) 
percentile ranks for the following subtests will be calculated: Alertness, Go/NoGo, Divided Attention, Visual 
Scanning. 
 
3.7 Aim 7 
To investigate whether there is a correlation between the effects of stimulation (in general) and/or the 
specific type of stimulation (gamma versus control) on the motor activity level measured by an actigraphy 
watch.  
 

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3.8 Aim 8 
To investigate if there is a relationship between the brain excitability derived from the subjective 
effect of tACS and the motor threshold measured by TMS. 
 
 
Specific Aims with Measures and Aim-Specific Statistical Analysis Plans 
 
Specific 
Aim 
Outcomes  
Measures 
Population Parameters 
to be Estimated 
(“Estimands”) 
Statistical  
Estimators 
Aim 1: 
To investigate 
the feasibility of 
cognitive testing 
during tACS 
Fraction of participants who complete both stimulation and cognitive 
testing sessions 
Proportion of participants 
with completed 
stimulation- and testing-
protocol  
Observed proportion 
and 95% C.I.  
Aim 2:  
Evaluate the 
effect of gamma-
tACS on memory 
testing 
Results of delayed ultra-delayed verbal memory and associative verbal 
memory recall (after stimulation, day after stimulation and 5 days after 
stimulation) for gamma versus control tACS 
 Memory recall in Rey 
Auditory Verbal Learning 
Test (a) and a word 
association test (b); 
amount of words and 
word-pairs remembered 
after stimulation, on day 
after stimulation and 5 
days later will be recorded 
 
Comparison 
between results 
after stimulation and 
sham on individual 
and group level 
(mean differences, 
regression 
coefficients, 
components of 
variance)  
Aim 3: 
Investigate 
feasibility (a) and 
acceptability (b) 
of wearable 
device (single-
channel EEG 
during the night) 
Fraction of participants wearing the device on (a) the first and (b) all 
three nights planned according to the protocol. 
 
Proportion of participants 
having worn the device 
during (a) the first and (b) 
all three nights for at least 
four hours each night 
Observed proportion 
and 95% C.I.  
Aim 4:  
Evaluate the 
effect of gamma-
tACS on sleep 
spindles (a) and 
slow wave sleep 
(b) compared to 
sham stimulation 
Amount of sleep spindles (a) and slow wave sleep (b) after tACS-
stimulation and control stimulation. 
 
Differences (individual 
level and means) of sleep 
spindle frequency 
(maximum number per 
hour) and slow wave 
activity (maximum 
minutes of slow wave 
sleep per hour) 
Comparison 
between results 
after gamma-tACS 
and control tACS on 
individual and group 
level (mean 
differences, 
components of 
variance, regression 
coefficients) 
Aim 5:  
To investigate 
whether there is 
a correlation 
between 
memory recall 
and sleep EEG 
Memory and associative memory recall performance; EEG features (as 
for aim 4) 
Correlation between 
changes in memory recall 
and sleep EEG (amount of 
spindles and slow wave 
sleep) for gamma- versus 
control tACS 
 Exploratory 
investigation 
of 
correlations 
(Pearson’s) between 
stimulation induced 
changes in memory 
recall 
performance
and 
sleep 
EEG 
features 
Aim 6: To 
investigate the 
effect of 
stimulation on 
different 
cognitive 
functions, i.e. a 
letter fluency 
task (a), 
executive 
functioning 
(Stroop Test (b), 
Trail Making Test 
(c)) and attention 
Effect of tACS and control stimulation on cognitive testing during and on 
the day after stimulation. 
For (a) the number of 
correct words, of 
perseverations and of rule 
breaks will be calculated. 
For (b) and (c) time for test 
completion and errors will 
be calculated. For (d) 
percentile ranks for the 
following subtests will be 
calculated: Alertness, 
Go/NoGo, Divided 
Attention, Visual Scanning 
 
Comparison 
between results 
after stimulation and 
sham on individual 
and group level 
(mean differences, 
regression 
coefficients, 
components of 
variance) 

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(Attentional 
Performance, 
TAP (d)) 
Aim 7: To 
investigate 
whether there is 
a correlation 
between motor 
activity level and 
stimulation 
Effect of stimulation on motor activity level  
Correlation between 
changes in the amount of 
motor activity the day 
after stimulation versus 
the day before; (a) after 
stimulation in general and 
(b) after gamma- versus 
control stimulation.  
Exploratory 
investigation of 
correlations 
(Pearson’s) between 
the day before and 
after the 
(respective) 
stimulations.  
Aim 7: To 
investigate 
whether there is 
a correlation 
between the 
TMS motor 
threshold and 
the tolerated 
tACS amplitude 
(based on 
subjective 
symptoms) 
Association between TMS motor threshold and symptoms from tACS 
Correlation between the 
level of TMS motor 
threshold and the highest 
tolerated tACS level (21Hz 
and 40Hz, lower value). 
Exploratory 
investigations of 
correlations 
(Pearson’s) between 
the measures (% and 
mA).  
 

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4. Study Design 
 
This is a single-center prospective interventional pilot study with a controlled crossover-design. Each participant is 
exposed once to the intervention (tACS) and once to the control intervention (control tACS) to allow not only an 
interindividual but also an intraindividual comparison of outcomes under both conditions. Thus, each participant 
can serve as their own control.  
 
First, an online prescreening (in REDCap) is performed, where basic eligibility information and informed consent for 
a screening by telephone is obtained. If, in the subsequent phone screen, inclusion/exclusion criteria are met and 
the participant provide verbal consent, a meeting on site (UNC Chapel Hill) will be arranged, where participants will 
sign informed consent and undergo baseline assessments (day 1). Afterwards, participants will receive the single-
channel EEG for the following night (night 1). The next day (day 2), the intervention (gamma-tACS or control tACS) 
during cognitive testing will take place. During the following night (night 2) the EEG will be worn again for recording 
of sleep EEG at home. The follow-up cognitive testing will be scheduled for the day after (day 3), and again for the 
fifth day after stimulation (memory recall by telephone).  
This procedure will be repeated for the respective other intervention (gamma-tACS or control tACS) one week (5-9 
days) later. Each participant will be wearing an actigraph (accelerometer wristband) during the study period. 
Additionally, we will perform motor thresholding by TMS on day 2. Additionally, TMS motor thresholding will take 
place during day 2.  
 
Centralized services are not used. All data (including baseline assessment, cognitive testing results) are stored in a 
REDCap database. 
 
4.1. Treatment Design 
Memory – as cognition in general – is based on synchronous oscillatory activity within and across neuronal 
networks. Neuronal network activity can be modified via non-invasive brain stimulation. Transcranial alternating 
current stimulation (tACS) is a well-established and safe form of non-invasive stimulation. Stimulation frequency 
and location is chosen to engage the neuronal networks of interest as a function of the psychological constructs 
investigated in a given study. Here, we will use gamma-frequency-tuned tACS targeting bilateral temporal lobes 
during cognitive testing including a verbal memory task, with ultra-delayed recall on the day after the stimulation 
and after five days.  
There is evidence for the improvement of episodic memory through the use of tACS in the gamma-frequency range 
in healthy participants ((8), (9), (10), (11)). We favor the temporal lobes over other locations for stimulation because 
gamma band brain activity occurs in temporal neocortex and hippocampus, both during memory encoding in the 
awake state and during memory consolidation in slow wave sleep ((12), (13), (14)). 
 
We decided for an alternative frequency (21 Hz) as control intervention in order to match the side effects associated 
with bilateral tempral stimulation.  The tACS amplitude will be titrated individually (evaluation of side effects; start 
with 2mA peak-to-peak, -0.25mA until side effects tolerable for at least 1 hour, respective testing for 40 Hz and for 
21 Hz, lower well-tolerated amplitude is being administered during tasks).  
 

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4.2.  Experimental Design 
This is a controlled cross-over study. Participants will be randomly allocated to the respective sequence (first tACS, 
then control stimulation – vice versa) via simple randomization, i.e. based on a single sequence of random sequence 
numbers generated by computer.  
 
4.3.  Measurement Design 
Table 1.  Variables of interest: their occasions of evaluation, their uses for the aims, their roles in the study 
Variables within 
Domains 
Scale1 
Occasions2  Aims3 Main Roles 
Identifiers 
 
 
 
 
Participant’s unique ID 
Nominal 
All 
All 
Identifier 
Intervention (A or B)* 
Binary 
E 
All 
Identifier 
General Profile 
 
 
 
 
Age  
Decimal yrs 
S 
All 
Screening, 
covariate uses 
Implanted 
device/hearing aid 
Binary 
S 
All 
Screening 
Cardiac pacemaker 
Binary 
S 
All 
Screening 
Willingness to abstain 
from alcohol ≥24h 
before visit 
Binary 
S 
All 
Screening 
Known neurologic 
diseases 
Binary 
S 
All 
Screening 
Known psychiatric 
diseases 
Binary 
S 
All 
Screening 
Known other medical 
conditions 
Binary 
S 
All 
Screening 
Brain surgery in the past Binary 
S 
All 
Screening 
Night shifts, bed after 
midnight 
Binary 
S 
All 
Screening 
Use of illegal drugs  
Binary 
S 
All 
Screening 
Sex 
Categorical 
0 
All 
Covariate uses 
Racial/ethnic categories 
Categorical 
0 
All 
Covariate uses 
Education 
Categorical 
0 
All 
Covariate uses 
Living conditions 
Categorical 
0 
All 
Covariate uses 
Work status 
Categorical 
0 
All 
Covariate uses 
Clubs/social 
organizations 
Binary 
0 
All 
Covariate uses 
Sports 
Binary, categorical 
0 
All 
Covariate uses 
Social contacts 
Binary, categorical 
0 
All 
Covariate uses 
Media consumption 
Categorical 
0 
All 
Covariate uses 
Concomitant 
medications list 
Nominal 
0 
All 
Covariate uses 

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Caffeine consumption 
Binary, nominal, dL 
0 
All 
Covariate uses 
Alcohol consumption 
Binary, nominal, dL 
0 
All 
Covariate uses 
Smoker 
Binary, yrs, cig/d 
0 
All 
Covariate uses 
Questionnaires 
 
 
 
 
Sleep Quality 
Assessment PSQI (15) 
Ordinal 0-21 
0 
All 
Screening 
Patient Health 
Questionnaire-9 (16) 
Ordinal 0-27 
0 
All 
Screening 
General Anxiety 
Disorder-7 (17) 
Ordinal 0-21 
0 
All 
Screening 
Alcohol Use Disorders 
Identification Test (1-3) 
(18) 
Ordinal 0-18 
S 
All 
Screening 
AD8 Dementia Screening 
(19) 
Ordinal 0-8 
0 
All 
Screening 
Montreal Cognitive 
Assessment (20) 
Ordinal 0-30 
0 
All 
Screening 
Epilepsy Screening (21) 
Binary 
0 
All 
Screening 
Handedness 
Questionnaire (22) 
Laterality Index 
0 
All 
Covariate uses 
Behavioral Inhibition and 
Behavioral Activation 
Self Report Scales 
(BIS/BAS)  (23)  
Ordinal, 4 subscales: 
BIS (7 to 28) 
BAS drive (4-16) 
BAS fun-seeking (4-16) 
BAS reward (7-20) 
0 
All 
Covariate uses 
Basic Sleep Habits 
hh:mm; hours/min 
0 
All 
Covariate uses 
Stimulation conditions 
 
 
 
 
Epileptiform activity in 
EEG 
Binary 
0 
All 
Early 
termination of 
study 
participation 
 
 
 
 
 
Karolinska Sleepiness 
Scale (24) 
Ordinal 1-10 
D1A, D2A, 
D1B, D2B 
Aim 2 Covariate use 
PANAS (Positive and 
Negative Affect 
Schedule) (25) 
Ordinal 20-100 
D1A, D2A, 
D1B, D2B 
Aim 2 Covariate use 
Sleep quality night 
before 
Categorical (nominal) 
D1A, D2A, 
D1B, D2B 
Aim 2 Covariate use 
Cognitive testing 
 
 
 
 
Completed 
Binary 
D1A, D2A, 
D1B, D2B 
Aim 1 Primary 
outcome 
Delayed and ultra-
delayed recall from 
Rey Auditory Verbal 
Learning Test (RAVLT) 
(26) and from word 
Ratio 
(number of correct words); number of correct 
words for trials 1-5 (=learning), for trial 6 
(“interference”) and for trial 7 (“recall”); 
D1A, D2A, 
PA, D1B, 
D2B, PB 
Aim 2, 
Aim 5 
Primary 
outcome 

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association test; RAVLT 
encoding 
number of confabulations and perseverations 
in total) 
Time from encoding of 
RAVLT and word 
association test to 
delayed and ultra-
delayed recall 
Interval (hh:mm) 
D1A, D2A, 
PA, D1B, 
D2B, BP 
Aim 2 Covariate use 
Time from encoding of 
word association test to 
delayed and ultra-
delayed recall 
Interval (hh:mm)  
D1A, D2A, 
PA, D1B, 
D2B, BP 
Aim 2 Covariate use 
 
 
 
 
 
RAVLT 
 
Ratio 
(number of correct words for trials 1-5 
(=learning), for trial 6 (“interference”) and for 
trial 7 (“recall”); number of confabulations and 
perseverations in total) 
D1A, D1B 
Aim 2  Covariate use 
Word association test 
Ratio 
(number of correct words for trials 1-4) 
D1A, D1B 
Aim 2 Covariate use 
Letter Fluency (28) 
Ratio 
(number of correct words, number of 
perseverations and number of rule breaks) 
D1A, D2A, 
D1B, D2B 
Aim 6 Secondary 
outcome 
Stroop Color and Word 
Test (29) 
Interval (sec),  
ratio (errors) 
D1A, D2A, 
D1B, D2B 
Aim 6 Secondary 
outcome 
Trail Making Test A and B 
(30) 
Interval (sec),  
ratio (errors) 
D1A, D2A, 
D1B, D2B 
Aim 6 Secondary 
outcome 
Test of Attentional 
Performance (TAP) (31) 
Interval, ratio 
(Alertness: Percentile rank of median reaction 
time for correct responses, percentile rank of 
standard deviation; Go/NoGo: Percentile rank 
of median reaction time for correct responses, 
percentile rank of standard deviation, 
percentile rank of errors;  Divided Attention: 
Percentile rank of median reaction time for 
correct responses, percentile rank of standard 
deviation, percentile rank of errors, percentile 
rank of omissions; Visual Scanning: Percentile 
rank of median of critical and non-critical, 
respective standard deviation, omissions)  
D1A, D2A, 
D1B, D2B 
Aim 6 Secondary 
outcome 
Sleep EEG  
 
 
 
 
First night with ≥4 hours 
of recording 
Binary (hh:mm) 
N1 
Aim 3 Primary 
outcome;  
 early 
termination of 
study 
participation if 
<4 hours 
EEG worn for ≥4h hours 
in 3/3 nights 
Binary (nights) 
N1, N2A, 
N2B 
Aim 3 Primary 
outcome 

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Sleep latency 
Minutes 
N1, N2A, 
N2B 
Aim 4, 
Aim 5 
Covariate use 
Sleep efficiency 
% 
N1, N2A, 
N2B 
Aim 4, 
Aim 5 
Covriate use 
Sleep spindles, slow 
wave sleep 
Amount/hour 
N1, N2A, 
N2B 
Aim 4, 
Aim 5 
Primary 
outcome 
Subjective tolerability of 
headband 
Binary, nominal 
N1, N2A, 
N2B 
Aim 3  Exploratory use 
Actigraphy 
 
 
 
 
Motor activity/24 hours, 
resting time for sleep 
%, hours 
N2A, D2A, 
N2B, D2B 
Aim 7 Exploratory 
outcome 
Thresholding 
 
 
 
 
TMS motor threshold 
% MSO (maximal stimulator output)  
D2A 
Aim 8 Exploratory 
outcome 
tACS thresholding 
mA (lower value of 21 Hz and 40 Hz) 
D2A 
Aim 8 Exploratory 
outcome 
Safety Monitoring 
 
 
 
 
AEs and SAEs 
documentation 
Events 
All 
All 
Safety 
monitoring 
 
 
 
1 Units of measurement or the scale. 
 
 
2 Occasions of evaluation or retrieval:   
S = Screening 
0 = Enrollment and Baseline  
N1 = Night 1  
D1A = Day 1 in Intervention A 
N2A = Night 2 in Intervention A  
D2A = Day 2 in Intervention A 
PA = Phonecall in Intervention A 
D1B = Day 1 in Intervention B 
N2B = Night 2 in Intervention B  
D2B = Day 2 in Intervention B 
PB = Phonecall in Intervention B 
 
 
 
3 The specific aims in which the variable will play a role in data analyses. 
 
 
4 Uses: assess medication adherence, mediation analyses, and exploratory analyses  
 
 
*Intervention:   
 
 
A = tACS   
 
 
B = control stimulation 

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5. Study Participants 
5.1. Numbers of Participants 
 
5.1.1. Number to be screened:  N ≤ 100 
 
 
5.1.2. Number to be enrolled:   N ≤ 50 
The sample size is 28 participants in the final dataset, i.e. the participants who completed all the visits for the 
primary outcomes, i.e. Visits 1, 2, 3, 4, 5, 6, 7 (including the three nights with EEG). However, to ensure that 28 
participants complete the experiment, we conservatively estimate to screen 100 participants and to enroll 50 
participants as a ceiling for the sake of IRB approval. The motivation for the sample size of 28 participants is the 
following power analysis: power analysis: dz = 0.5, 1-beta = 0.80, alpha = 0.05. Participants who drop-out or have 
missing data will be replaced.  
Recruitment takes place in the general population.  
 
5.2. Eligibility Criteria 
Participants have to complete a set of questions (in REDCap) during the screening process. They will be instructed 
to consume no alcohol and no more caffeine than usual 24 hours before each study visit. 
 
 
5.2.1. Inclusion Criteria  
In order to be eligible to participate in this study, an individual must meet the following criterium: 
• 
 >50 years old  
 
 
5.2.1. Exclusion Criteria  
Any individual who meets one or more of the following criteria will be excluded from participation: 
• 
Implanted device or metal in head (including cochlear implant or other hearing aid), cardiac pacemaker 
or any other powered medical device 
• 
Known neurological disease from history (epilepsy, sleep disorder (insomnia, sleep apnea, restless legs 
syndrome, parasomnia), stroke or transitory ischemic attack, cognitive impairment, neurodegenerative 
disease (for example Alzheimer’s disease, Parkinson’s disease or amyotrophic lateral sclerosis), 
immune-mediated disease of the central nervous system, chronic infectious brain disease, brain tumor, 
traumatic brain injury with loss of consciousness and/or intracranial bleeding, chronic pain with the 
need for daily analgesic use) 
• 
Positive screening for epilepsy (questionnaire) 
• 
Pathological Montreal Cognitive Assessment (MoCA <26/30 points)  
• 
Brain surgery in the past (lifetime) 
• 
Known psychiatric disorder from history (schizophrenia (lifetime), obsessive compulsive disorder (OCD; 
lifetime), borderline personality disorder (lifetime), anxiety disorder (lifetime), bipolar disorder 
(lifetime), psychosis (lifetime), eating disorder (lifetime), depression (within the last three months) 
• 
Positive screening for anxiety disorder (GAD-7 ≥10/21 points) or positive screening for depression (PHQ-
9 ≥5/27 points)   
• 
Known other relevant medical condition from history(moderate to severe chronic obstructive 
pulmonary disease (COPD), abnormal kidney function (defined as estimated Glomerular Filtration Rate 
<60ml/min), current liver disease (defined as hepatitis and/or liver cirrhosis), cancer, diabetes mellitus, 
cardiac disease (heart failure, myocardial infarct, atrial fibrillation and revascularization – all within the 
last three months) 
• 
Working in night shifts or going to bed after midnight on 3 or more nights per week 
• 
Positive screening for sleep disorder (PSQI >5/21 points) 

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• 
Psychotropic treatment or illegal drugs (including cannabis) within the last three months 
• 
Indication for alcohol use disorder: AUDIT score (Alcohol Use Disorders Identification Test; screening for 
unhealthy alcohol use) ≥7 for females and for males ≥ 65 years or ≥8 for males <65 years 
• 
Not willing to abstain alcohol at least 24 hours before each study visit 
• 
Women who want to become pregnant, are pregnant, plant to seek or are seeking fertility treatment 
 
5.3. Enrollment/Selection Strategies 
 
5.3.1.  Prospective Recruitment 
We will advertise the study directly to the public on websites such as ClinicalTrials.gov, studypages.com, Research 
For Me, frohlichlab.org and Carolinaneurostimulation.org. We will have contact information and a summary of the 
clinical trial posted on the Frohlich Lab Facebook and Twitter pages. We will also be launching a Facebook or 
Instagram advertisement to identify potential participants. Furthermore, we will also be using the UNC Mass email 
and department listserv to send out an email containing the advertisement. In addition, we will post fliers senior 
living communities. We have previously recruited about 50 participants from an identical population within 3 
months. 
We will send unencrypted emails to facilitate the initial contact to potential participants. Medical information is 
never requested per email. All medical information is recorded through HIPAA conform Zoom meetings and REDCap 
surveys.  
The advertisement will include a link to a brief prescreening survey on REDCap to help identify participants. 
Interested individuals can then either visit the specified website and complete an online screening survey on 
REDCap or call or email to register for a telephone prescreening. All participant identifiers will be stored in REDCap 
and password encrypted tables stored on UNC servers until recruitment is over. When recruitment is over, all 
patients who do not consent or are not eligible for participation in the study will have their responses permanently 
deleted. 
Our retention strategy includes a payment schedule of two times $50 per participants. Thus, completion of the 
study will result in a financial compensation of $100. 
  
 
5.3.2. Screen Failures    
In the case that a participant enrolls in the trial and the screening reveals that they do not meet study criteria, the 
study personnel completing the interviewing process will clearly explain why the participant does not meet criteria. 
If a time-sensitive criterion is not met, re-screening may occur at a later time. In the worst case, we expect only 
~25% of those interested to be eligible. 
 
5.4. Strategies for Retention 
Due to the low time burden (five study visits on site) at short intervals (maximum two weeks), we expect a low 
drop-out rate. Nevertheless, we are capturing data on possible reasons in case of discontinuation.   
 
5.5.  Matching and Stratification 
Not applicable.  

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5.6.  Randomization  and  Concealment 
Participants will be assigned to active stimulation first or sham stimulation first using simple randomization. 
5.7.  Blinding 
This is a double-blind study. Both participants and research staff will be blinded to the stimulation condition. 
 
 

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6. Treatment Design: Procedures 
Description    
Transcranial alternating current stimulation (tACS) 
Participants will be stimulated with the commercial, CE-certified Neuroconn multiple channel (MC) stimulator. The 
use of this device routinely received a non-significant risk (NSR) designation on review by the full UNC IRB. The 
NeuroConn device description is as follows: The DC-STIMULATOR MC is a CE-certified medical device for conducting 
non-invasive transcranial current stimulation in humans. The DC-STIMULATOR MC is a micro-processor-controlled 
current source. It meets the highest safety standards thanks to (hardware- and software-based) multistage 
monitoring of the current path. By continuously monitoring electrode impedance it can detect insufficient contact 
with the skin and automatically terminate stimulation, maximizing patient safety. The device includes a digital 
display with various stimulation modes to be selected and stimulation parameters such as current strength, 
duration, fade-in and fade-out to be set.  
DC-STIMULATOR MC features:  
• 
4 programmable, micro-processor-controlled constant current sources using 25 ndependent channels 
(optional: 16 channels)  
• 
For transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), cranial 
electrical stimulation (CES), galvanic vestibular stimulation (GVS) and transcranial random noise stimulation (tRNS)  
• 
4 standard modes – tDCS (continuous stimulation) – pulse (cyclical stimulation activation/deactivation) – 
sinus (sinus wave) – noise (normally distributed)  
• 
Current strength and curve forms adjustable up to ±4,000 μA, AC current strength adjustable up to 8,000 
μA (peak-to-peak)  
• 
Frequencies adjustable up to 1,000 Hz, phase freely adjustable  
 
Electroencephalography (EEG):  
A high-density EEG net (128 electrodes including electrooculography electrodes; EGI, Inc.). Continuous qEEG 
recording will be performed. Sampling rate during the continuous recording will be 1 kHz with Cz as the reference 
and a channel between Cz and Pz as ground, using an EGI system with SDK AmpServer Pro (Geodesic, Eugene, 
Oregon). 
 
Transcranial magnet stimulation (TMS) motor thresholding: 
Additionally, TMS motor thresholding (M. interosseus dorsalis I, with EMG electrodes) will be performed, as there 
is evidence suggesting a relationship between the effect of tACS and brain excitability measured with single pulse 
TMS. We therefore measure cortical excitability by performing motor thresholding using single pulse TMS 
(transcranial magnetic stimulation) during Visit 2. A MagVenture MagPro X100 TMS device will be used.  
 
Dosing and Administration   
The research team will first measure each participant's head using the 10-20 system to determine the electrode 
locations. Participants will then be fitted with the 4 electrodes for stimulation: two 4.5x4.5cm electrodes placed 
over T7/P7 and T8/P8 (10/20-EEG-system). Electrodes will be carbon rubber, with Ten20 conductive paste applied.  
 
For gamma-tACS 40 Hz will be applied (“natural target value”, for a review see (33)). We have decided to apply 
control stimulation instead of sham stimulation as we have been able to demonstrate visual side effects with 
bitemporal asynchronous stimulation (i.e. synchronized within one hemisphere) which differ according to 
stimulation frequency (phosphenes with higher frequencies, sensation of movements of the environment with 
lower frequencies). Hence, 21 Hz tACS will be applied for control stimulation (reasoning: no known specific effects 
on temporal lobe; close to gamma-stimulation and hence similar concerning side effects; not a harmonic frequency 
to 40 Hz). An individual current amplitude will be determined before stimulation (for 21 Hz and 40 Hz; ramp-on 40s, 
continuous stimulation 20s; from 2mA peak-to-peak in steps of 0.25mA until “symptoms well tolerable for at least 

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one hour”. The lower of the two current amplitudes from 40 Hz and 21 Hz will be applied for both stimulation 
conditions).  
 
For both stimulation sessions, a ramp-on and ramp-off time of 40s will be applied.  
 
Researchers will monitor participants during stimulation. Personnel will be thoroughly trained and have trainings 
documented on the transcranial stimulation device and will be present during all stimulation sessions. Co-
investigator Andrea Seiler MD is a Swiss board-certified neurologist who will serve as supervisor for the stimulation 
study visits. 
 
During stimulation, the participants will perform the following cognitive tests presented on the computer screen or 
on paper: RAVLT (Rey Auditory Verbal Learning Test) (26), a word association test (8 word-pairs), Letter Fluency 
(28), Stroop Color and Word Test (29), Trail Making Test A and B (30), TAP (Test of Attentional Performance) (31). 
The stimulator will be triggered by remote control from the experiment script and will administer stimulation during 
each single test. After each block of stimulation, an eyes-open resting state EEG will be performed. All stimulation 
involves 20 seconds of ramp-in time and 20 seconds of ramp-out time. The total duration of the stimulation and 
testing is approximately 40 minutes. 

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7. Schedule of Activities and Procedures 
7.1. Table of Events 
 
Procedure 
Visit 0 
screening 
(online/phone) 
Visit 1 
Baseline 
(from 
day 
after Visit 0 
to 
+14 
days) 
Visit 2  
(day after 
Visit 1) 
Visit 
3 
(day after 
Visit 2) 
Visit 
4 
(telephone; 
5 days after 
Visit 2) 
Visit 5  
(6-9 days 
after Visit 
2) 
Visit 6  
(day after 
Visit 5) 
Visit 
7 
(telephone; 
5 days after 
Visit 5) 
Recruitment 
Informed consent 
X 
(oral) 
X 
(written) 
 
 
 
 
 
 
 
Eligibility 
assessments 
X 
X 
 
 
 
 
 
 
 
Enrollment 
and 
randomization 
 
X 
 
 
 
 
 
 
Eligibility 
assessments 
 At least 4 hours 
of initial sleep-
EEG 
 
 
x 
 
 
 
 
 
 
No 
epileptiform 
discharges 
in 
baseline-EEG 
 
x 
 
 
 
x 
 
 
 
No psychotropic 
treatment/illegal 
drugs within the 
last 3 months, no 
alcohol within the 
last 24 hours  
 
 
x 
x 
 
x 
x 
 
Intervention 
(Control) 
Stimulation  
 
 
X 
 
 
X 
 
 
 
Cognitive  
testing1 
 
 
X 
X 
X 
(only 
verbal 
memory 
and 
associative 
verbal 
memory 
recall) 
X 
X 
X 
(only 
verbal and 
associative 
verbal 
memory 
recall) 
 
Sleep-EEG2 
 
X 
(next night) 
X 
(next 
night) 
 
 
X 
(next 
night) 
 
 
 
Actigraphy 
 
X 
X 
X 
X 
X 
X 
 
 
TMS 
Motor 
Thresholding 
 
 
X 
 
 
 
 
 
Patient 
Reported  
Outcome 
Subjective 
tolerability 
of 
sleep EEG 
 
 
X 
X 
 
 
X 
 
 
Sleepiness 
(Karolinska Scale) 
 
 
X 
X 
 
X 
X 
 
 
Sleep quality  
 
 
X 
X 
 
X 
X 
 
 
Affect 
(PANAS) 
 
 
X 
X 
 
X 
X 
 
Safety  
Monitoring 
Assessment 
of 
AEs 
 
 
X 
X 
X 
X 
X 
X 
 
1 Standardized results of: RAVLT (Rey Auditory Verbal Learning Test) (26), word association test, Letter Fluency (28), 
Stroop Color and Word Test (29), Trail Making Test A and B (30), TAP (Test of Attentional Performance) (31). 
2 Device worn (yes/no), hours of recording, sleep latency, sleep efficiency, amount of sleep spindles and slow wave 
sleep. 
 

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7.2.  Screening 
The pre-screening can be performed via REDCap (questions 1, 2, 3, 4); the whole screening (questions 1-12) is 
performed via telephone. Result of the screening procedure: eligible or not eligible.  
The following questions will be asked:  
1. Are you at least fifty years old? If not, then not eligible.  
2. Do you have an implanted device or metal in your head (including a cochlear implant), or do you have hearing 
aids? If yes, then not eligible.  
3.  Do you have a cardiac pacemaker? If yes, then not eligible.   
4. Alcohol Use Disorders Identification Test (AUDIT) 1-3: Gender: Woman / man / transgender / non-binary / prefer 
not to respond. Age: <65 years / ≥65 years? How often do you have a drink containing alcohol? How many drinks 
containing alcohol do you have on a typical day when you are drinking? How often do you have 4 (for females) or 5 
(for males) – or more – drinks on one occasion? Cutoff (i.e. not eligible): ≥7 for females and for males ≥ 65 years; ≥8 
for males <65 years.  
5. Are you willing to abstain alcohol at least 24 hours before each study visit? If no, then not eligible.  
6. Have you ever been told by a healthcare provider that you have one of the following neurologic diseases: Epilepsy, 
sleep disorder (insomnia, sleep apnea, restless legs syndrome, parasomnia), stroke or transitory ischemic attack, 
cognitive impairment, neurodegenerative disease (for example Alzheimer’s disease, Parkinson’s disease or 
amyotrophic lateral sclerosis), immune-mediated disease of the central nervous system, chronic infectious brain 
disease, brain tumor, traumatic brain injury with loss of consciousness and/or intracranial bleeding, chronic pain 
with the need for daily analgesic use? If yes, then not eligible.  
7. Did you ever have brain surgery? If yes, then not eligible. 
8. Have you been told by a healthcare provider that you have one of the following psychiatric diseases (in your 
lifetime or during the last three months): Schizophrenia (in your lifetime), obsessive compulsive disorder (OCD; in 
your lifetime), borderline personality disorder (in your lifetime), anxiety disorder (in your lifetime), bipolar disorder 
(in your lifetime), psychosis (in your lifetime), eating disorder (in your lifetime), depression (during the last three 
months)? If yes, then not eligible. 
9. Have you ever been told by a healthcare professional that you have one of the following medical conditions: 
Moderate to severe chronic obstructive pulmonary disease (COPD), abnormal kidney function (defined as estimated 
Glomerular Filtration Rate <60ml/min), current liver disease (defined as hepatitis and/or liver cirrhosis), cancer, 
diabetes mellitus, cardiac disease (heart failure, myocardial infarct, atrial fibrillation and revascularization – all 
within the last three months)? If yes, then not eligible. 
10. Do you work night shifts (last three months)? If yes, then not eligible. 
11. Do you usually go to bed after midnight (last three months)? If yes, then not eligible.  
12. Have you used psychotropic treatment or illegal drugs (including cannabis) within the last three months? If yes, 
then not eligible. 
 
If online pre-screening is successfully completed and the participant appears eligible, the following message will 
appear: Please leave name, email, phone number and preferred time to be called by phone. 
 
The following information will be provided by telephone:  
1. A brief summary of the study and its objectives.  
2. Instructions for the meeting at the lab:  
2.1 In the 24 hours before the visit: Please do not drink alcohol and do not drink more caffeine than you 
usually do.  
2.2 Please bring a list of all medications you regularly take (including those not prescribed by a healthcare 
professional). 
 
If not yet the case, the online questions will be completed by phone. 
 
There may be up to 28 days between (pre-)screening and enrollment. 

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7.3. Enrollment 
Visits 0 and 1 
The following procedures will occur:  
1. Signing of informed consent 
2. Completion of demographics and supplementary questions (mainly providing information about the cognitive 
state): Sex, racial/ethnic categories, education, living conditions, work status, clubs/social organizations, sports, 
social contacts, media consumption, concomitant medications list, caffeine consumption, alcohol consumption, 
smoking status.  
3. Specific questionnaires to exclude patients with indications for a sleep disorder, depression, anxiety disorder, 
cognitive impairment, epilepsy:  
3.1 Sleep Quality Assessment PSQI (15): Screening for sleep disorders. Result: 0-21 points. Exclusion if >5 points.  
3.2 Patient Health Questionnaire-9 (16): Screening for depression. Result: 0-27 points. Exclusion if ≥5 points.  
3.3. General Anxiety Disorder-7 (17): Screening for anxiety disorder. Result: 0-21 points. Exclusion if ≥10 points.  
3.4. Montreal Cognitive Assessment (MoCA): Screening for dementia. Result: 0-30. Exclusion if <26.  
4. Complementary questionnaires to complete patient profile:  
4.1 Handedness Questionnaire (22) 
4.2 Behavioral Inhibition and Behavioral Activation Self Report Scales (BIS/BAS) (23): These scales are used to 
monitor the perceived sensitivity to reward and punishment. BIS/BAS is broken into four sub-scores: BIS (7 to 28), 
BAS drive (4-16), BAS fun-seeking (4-16), and BAS reward (7-20). 
4.3 Basic sleep habits (bedtime, sleep latency, wakefulness during the night, waking time, total amount of sleep on 
average, optimal total amount of sleep)  
5. The following instructions will be given for the night and following day:  
851 How to use the EEG-headband the night before visit 2 (oral and written instructions, including sleep diary); how 
to use the actigraphy watch. 
5.2 To not consume more caffeine than usually. To please not drink alcohol.  
6. The participant will be randomized to the respective intervention for visit 2 (either gamma-tACS or first control 
stimulation).  
 
7.4. Study Visits 
Visit 2 (day after Visit 1; afternoon/early evening, i.e. start between 12pm and 6pm) 
1. Questioning whether there has been any use of alcohol, psychotropic substances or illicit drugs during the past 
24 hours. If yes, study participation is terminated. 
2. Questions to assess current sleepiness and mood, as this may affect the results of further testing:  
2.1 Questions for sleep quality the night before 
2.2 Karolinska Sleepiness Scale (24) 
2.3 Positive And Negative Affect Schedule (PANAS) (25) 
3. Motor thresholding by TMS. 
4. Thresholding individual tACS amplitude.  
5. Gamma-tACS or control stimulation (according to randomization) during the following cognitive tests, presented 
on a computer screen (2 minutes of resting EEG without stimulation after each test; total duration approximately 
40 minutes):  
5.1 Rey Auditory Verbal Learning Test (RAVLT, version 1) (26) 
5.2 Letter Fluency; letters F, A, S (28) 
5.3 Stroop Color and Word Test (29) 
5.4 Trail Making Test A and B (30) 

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5.5 Word association test; version 1 
5.6 Four subtests of the Test of Attentional Performance (TAP) (31): Alertness, Go/Nogo, Divided Attention, 
Visual Scanning 
5.7 RAVLT delayed recall 
6. Evaluation of side effects with open question (“Did you feel anything particular or note anything special during 
this session?”) 
7. The participant will be given the sleep diary for the second night with the EEG headband. 
 
Visit 3 (day after Visit 2; morning, i.e. start between 8am and 12pm) 
 
1. Questioning whether there has been any use of alcohol, psychotropic substances or illicit drugs during the past 
24 hours. If yes, the participant is excluded. 
2. Questions to assess current sleepiness and mood, as this may affect the results of further testing:  
3.1 Questions for sleep quality the night before 
3.2 Karolinska Sleepiness Scale  
3.3 Positive And Negative Affect Schedule (PANAS)  
3. Cognitive follow-up testing 
4.1 RAVLT “ultra-delayed” recall; version 1 
4.2 Letter fluency; letters B, H, R 
4.3 Stroop Color and Word Test (SCWT)  
4.4 Trail Making Test Part A and B 
4.5 Word association recall; version 1 
4.6 Four subtests of the Test of Attentional Performance (TAP): Alertness, Go/NoGo, Divided Attention, 
Visual Scanning 
 
 
Visit 4 (telephone; 5 days after Visit 2) 
Performed by telephone. 
1. Assessment of adverse events.  
2. RAVLT “ultra-delayed” recall; version 1. 
3. Word association recall; version 1. 
 
Visit 5 (6-9 days after Visit 2; afternoon/early evening, i.e. start between 12pm and 6pm)  
The day before: reminder (e-mail/SMS/phone call, depending on the participant's preference) of appointment on 
the following day - including request to abstain from alcohol and drugs as well as from excessive caffeine 
consumption. 
1. Questioning whether there has been any use of alcohol, psychotropic substances or illicit drugs during the past 
24 hours. If yes, the participant is excluded. 
2. Questioning if there is a new diagnosis. If yes, the participant will be excluded if the diagnosis meets exclusion 
criteria. 
3. Questions to assess current sleepiness and mood, as this may affect the results of further testing:  
3.1 Questions for sleep quality the night before 
3.2 Karolinska Sleepiness Scale  
3.3 Positive And Negative Affect Schedule (PANAS) 
4. Gamma-tACS or controlstimulation (according to randomization) during the following cognitive tests, presented 
on a computer screen (2 minutes of resting EEG without stimulation after each test):  
4.1 Rey Auditory Verbal Learning Test (RAVLT, version 2)  
4.2 Letter Fluency; letters F, A, S  

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4.3 Stroop Color and Word Test  
4.4 Trail Making Test A and B  
4.5. Word association test; version 2 
4.6 Four subtests of the Test of Attentional Performance (TAP): Alertness, Go/NoGo, Divided Attention, 
Visual Scanning 
4.7 RAVLT delayed recall; version 2 
5. Evaluation of side effects with open question (“Did you feel anything particular or note anything special during 
this session?”) 
6. The participant will be given the sleep diary for the third night with the EEG headband. 
 
Visit 6 (day after Visit 5; morning, i.e. start between 8am and 12pm) 
1. The participant brings back the EEG-headband (used the night before). Data quality check, review of sleep diary. 
2. Questioning whether there has been any use of alcohol, psychotropic substances or illicit drugs during the past 
24 hours. If yes, the participant is excluded. 
3. Questions to assess current sleepiness and mood, as this may affect the results of further testing:  
3.1 Questions for sleep quality the night before 
3.2 Karolinska Sleepiness Scale  
3.3 Positive And Negative Affect Schedule (PANAS)  
4. Cognitive follow-up testing 
4.1 RAVLT “ultra-delayed” recall; version 2 
4.2 Letter fluency; letters B, H, R 
4.3 Stroop Color and Word Test (SCWT)  
4.4 Trail Making Test Part A and B 
4.5 Word association recall; version 2 
4.6 Four subtests of the Test of Attentional Performance (TAP): Alertness, Go/NoGo, Divided Attention, 
Visual Scanning 
 
Visit 7 (telephone; 5 days after Visit 5) 
Performed by telephone. 
1. Assessment of adverse events.  
2. RAVLT “ultra-delayed” recall.  
3. Word association recall; version 2. 
 
7.5. Early Discontinuations  
Data to be Collected    
If the study participation has to be terminated early by the investigators (due to safety concerns), or if a participant 
chooses to withdraw from the study, including the case of not showing up for scheduled visits on site (Visits 1, 2, 3, 
5, 6), the data collected to date will not be included for the cognitive and sleep-EEG outcomes and the participant 
will be replaced. However, early discontinuation will be included in the data set for the feasibility outcomes as 
appropriate. Visits 4 and 7 are not mandatory for study completion.  
Criteria for Intervention Discontinuation    
An investigator may discontinue or withdraw a participant from the study for the following reasons: 
 
• 
Any clinical adverse event (AE), intercurrent illness or other medical condition, or situation occurs such that 
continued participation in the study would not be in the best interest of the participant. 

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• 
The participant meets any exclusion criteria (either newly developed or not previously recognized) or a 
reason for immediate early termination of participation. 
 
7.6. Enrollees May Drop Out 
Participants may voluntarily withdraw from participation at any time, for any reason, with no penalty or loss of 
rights. In case of no-show, an attempt will be made to contact the participant (by mail or phone). The reasons for 
drop-out and missing data will be documented in the database. 

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8. Statistical Analysis Plans 
8.1. Strategies that Apply to all the Aims 
All testing described below assumes a significance threshold of p = 0.05. Analyses will be deemed to be statistically 
significant if the p-value is less than this threshold. An analysis that does not exceed this threshold will be considered 
inconclusive. The proposed statistical analysis strategy acknowledges that no p-value can reveal the plausibility, 
presence, truth, or importance of an association or effect. 
 
There may be additional covariates included in the analysis. Data will be assessed for normality and, if deemed 
necessary, corrective procedures will be applied (e.g., log normalization). This correction will be applied upon 
consideration of the variables themselves, and not based on the result of the intended analysis. 
 
8.2 Sample Description 
The sample will be described using the following parameters: Age, sex, racial/ethnic categories, education, living 
conditions, work status, clubs/social organizations, sports, social contacts, media consumption, caffeine and alcohol 
consumption, smoking status. Whenever feasible, graphical methods will be used to describe the sample. 
Continuous data will be described using means, standard deviations, and confidence intervals, while categorical 
data will be described using counts/percentages.  
 
8.3 Aim-Specific Plans 
 
Plans for Aim 1.  
 
a) The proportion of participants in which stimulation and cognitive testing could be completed will be calculated 
after both stimulation sessions, i.e. visit 2 and visit 4 (percentage and 95% confidence interval).  
   
 
 
Plans for Aim 2.  
To evaluate the effect of gamma-tACS on cognitive testing. 
 
a) Primary outcome: Ultra-delayed verbal memory recall (i.e. amount of words and word associations remembered 
the day after encoding the RAVLT) after gamma-tACS compared to after control stimulation, intra- and 
interindividually.  
We will perform a two-way or one-way repeated measure ANCOVA with time (baseline and post-treatment) and 
treatment (control vs gamma-tACS) as within-subjects factors, and the order in which tACS will be applied  (tACS-
sham or control tACS) as covariate. Post-hoc tests will be calculated after Bonferroni correction for multiple 
comparisons. 
 
Null hypothesis: There is no difference between tACS and control stimulation for ultra-delayed memory recall one 
day after stimulation. Alternative hypothesis: Memory recall is better after gamma-tACS than after control 
stimulation. 
 
 
b) Secondary outcomes: Verbal and associative learning (immediate and delayed recall, recall after 5 days) and 
executive functions (results of Letter Fluency, Stroop Test, Trail Making Test, Tests of Attentional Performance), 
comparison intra- and interindividually, after gamma-tACS and control stimulation (comparison of difference 

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between visit 1-visit 2 and visit 3-visit 4; comparison of absolute results of visit 1 versus visit 3 and visit 2 versus visit 
4; statistical tests and covariates as in a)).  
Hypotheses are the same as for the primary outcome.  
 
 
Plans for Aim 3.  
To investigate the feasibility and adherence to wearable device (single-channel EEG during the night). 
 
a) The proportion (percentage and 95% confidence interval) of participants with at least four hours of EEG recording 
in the first night.  
 
 
b) The proportion (percentage and 95% confidence interval) of participants with at least four hours of recorded 
nocturnal data for each of all three nights. 
 
 
 
Plans for Aim 4.  
To evaluate the effect of gamma-tACS compared to control stimulation on sleep EEG. Differences (individual level 
and group level, statistical tests as mentioned above) of sleep latency (minutes from lights out to sleep onset), sleep 
efficiency (sleep duration in relation to time spent in bed), sleep spindle frequency (maximum number per hour) 
and slow wave activity (maximum minutes of slow wave sleep per hour).  
The statistical method will be the same as for Aim 2. 
Null hypothesis: Sleep EEG does not change after gamma-tACS compared to the night after control stimulation.  
Alternative hypothesis: There is a higher amount of sleep spindles and/or slow wave sleep after gamma-tACS 
(compared to the control).  
   
 
 
Plans for Aim 5.  
To investigate whether there is a correlation (Pearson’s) between the stimulation-induced changes in cognitive 
testing scores and sleep EEG features after gamma-tACS versus after control stimulation (on individual and group 
level). This is an exploratory analysis. 
 
 
Plans for Aim 6.  
Comparison of cognitive test results after stimulation and sham on individual and group level using ANCOVA (see 
CT.gov). This is an exploratory analysis.  
 
Plans for Aim 7. To investigate whether there is a correlation (Pearson’s) between the stimulation-induced changes 
in motor activity features (according to the wristband accelerometer results) after stimulation in general and after 
gamma-tACS versus after control stimulation (on individual and group level). This is an exploratory analysis.  
 
Plans for Aim 8.  
To investigate whether there is a correlation (Pearson’s) between the motor threshold (TMS) and the 
subjective symptoms during tACS. This is an exploratory analysis.  
 
  
8.4 Planned Interim Analyses 
No interim analyses will be performed.  
 
 

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9. Sample Size Rationale 
We plan to recruit 28 healthy adults in this feasibility study (primary outcome). The sample size was computed such 
that the study has 95% power (alpha = 0.05) to reject the null hypothesis that 50% of the population of interest can 
complete the study procedures for an effect size of g = 0.3, meaning that if at least 80% of the study sample 
complete the procedures, feasibility in the population of at least 50% is established. 
10. Data Capture and Database Management 
10.1. Software for Data Capture 
Data will be entered into a data capture system provided by TraCS Clinical Research Data Management Service 
(REDCap). REDCap is a 21 CFR Part 11-compliant data capture system provided by the NC TraCS Institute at UNC. 
The data system includes password protection and internal quality checks, such as automatic range checks, to 
identify data that appear inconsistent, incomplete, or inaccurate.  
 
10.2. Responsibilities for Data Capture and Database Management 
Data collection is the responsibility of the clinical trial staff at the site under the supervision of the site investigators 
(principal investigator and co-investigator). The investigator is responsible for ensuring the accuracy, completeness, 
legibility, and timeliness of the data reported. 
Hardcopies of the study visit worksheets will be provided for use as source document worksheets for recording data 
for each participant enrolled in the study.  Data recorded in the electronic case report form (eCRF) derived from 
source documents should be consistent with the data recorded on the source documents.  
Clinical data (including adverse events (AEs), concomitant medications, and expected adverse reactions data) will 
be entered into REDCap. The data system includes password protection and internal quality checks, such as 
automatic range checks, to identify data that appear inconsistent, incomplete, or inaccurate. Clinical data will be 
entered directly from the source documents. Trained research personnel (including the co-investigator) will have 
complete access to the REDCap system, while the principal investigator will have read-only ability. 
 
10.3. Study Records Retention 
According to the University of North Carolina at Chapel Hill’s Archives and Record Management Services schedule 
for General Records Retention and Disposition Schedule 6.10, records will be kept for 5 years after the completion 
of the study or grant end date, whichever is later. 
 
 
 

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11. Collection and Management of Tissue Specimens 
Not applicable. 
12. Safety Monitoring and Management 
12.1. Risk / Benefit Assessment 
Potential Risks:  
Risk of Confidentiality Breach: To avoid the uncommon event breaches in confidentiality, study documents that 
contain personal information, including the informed consent document, will be kept in locked filing capinets 
in locked rooms. The document that links study ID numbers to personal identifying information will be a 
password-protected spreadsheet. All data is stored in locked cabinets inside locked offices; electronic data will 
be stored only on password-protected computers, and data encryption methods will be used during 
communication between investigators. Interviews will be conducted over the HIPAA approved Zoom account. 
Only study personnel will have access to the data. All study staff participate in annual human participant training 
that includes education about responsibilities to minimize risk of confidentiality breach. 
 
Risk of Embarrassment: Self-report assessments contain questions regarding sensitive personal information. 
This uncommon risk is necessary in order to assess for relevant preexisting disorders. Participants will be 
assured upon intake that only study personnel will see any clinical ratings and that self-identifying information 
will not be collected alongside HIPAA protected information.  
 
Risk of Injury and Discomfort:  
The side effects of tACS are mild and transient; in fact, low intensity transcranial current 
stimulation, such as tACS, has been used for several years without any report of serious side effects. 
Furthermore, this stimulation mode has nothing to do with electroconvulsive therapy that applies 
many orders of magnitude higher stimulation current. Rather, transcranial current stimulation is so 
weak that it does not cause super-threshold activation of neurons. 
TACS does have some mild side effects, such as transient tingling, burning, pulsing sensation, or 
itching under the electrode sites (common). In a previous tACS trial we conducted, participants from 
all three groups of stimulation (two stimulation conditions, one was an active placebo group) 
reported either absent or mild side effects, and there was no difference between the groups with the 
exception of “flickering lights” (or phosphenes, p = 0.014). To monitor these mild side effects, we 
will be administering a stimulation questionnaire after each stimulation session to determine 
whether these effects were experienced and at what intensity. Research personnel is present during 
the full experiment. There have also been infrequent reports of reduced ability to focus, change in 
cognition, altered mood, headaches, and sleepiness. There is no evidence available that indicates that 
these potential side-effects are associated with stimulation versus study participation in general. In 
our previous depression work, we found no signal that supports an associated between any of these side-effects 
and the administration of tACS. Both the application of the tACS and the EEG 
electrodes can cause mild inconvenience such as mild headaches from the pressure of applying the 
electrodes. 
The motor thresholding procedure that uses TMS has been used without reports of any serious 
side-effects. Some subjects report muscle twitching during stimulation and sometimes a headache 
(common, <50% incidence), but these possible effects are transient and do not persist after we stop 
stimulation. The transcranial stimulator used in this study was cleared by UNC Hospital Medical 
Engineering, the in-house engineering team of UNC hospitals that test the safety of medical devices. 
This TMS device has been cleared by the FDA for some indications, such as Major Depressive 
Disorder in patients, but it has not been evaluated by the FDA for this study. To mitigate 

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uncomfortable side effects, during the study, we will ask about participants' comfort, and their 
participation will immediately be stopped if they are experiencing discomfort. In theory, there is a 
possibility that application of magnetic fields could induce a seizure. However, this has never been 
reported as occurring in general. In the broader field of TMS research, including riskier procedures 
than just motor thresholding, estimates of all seizure incidence is <0.02%, but due to its 
implausibility and theoretical nature, experts estimate that the likelihood of seizure during motor 
thresholding is much lower than this number. In the unlikely event of this occurring, trained medical 
professionals, including an expert in epilepsy and emergency seizure response, are on-site to 
respond. Furthermore, in order to mitigate this risk, we use multiple strategies. First, we screen 
participants based from participating in the study that present with any traits that may lower their 
seizure threshold or pose increased risk of seizure. These contraindications are well documented 
within the field and updated guidelines are released approximately every 10 years with the latest 
recommendation released in 2020 (Rossi et al. 2020). Contraindications screening is conducted 
during phone screening prior to the TMS session. Second, we have chosen our stimulation 
parameters to be within recommended safety guidelines. Third, we document regular trainings for 
personnel performing the motor thresholding procedure that matches standards recommended by 
expert consensus (Rossi et al. 2020, Fried et al. 2021). Fourth, we employ a comprehensive 
monitoring and adverse event assessment in each participant. 
Rossi S, Simone Rossi, Simone Rossi, Antal A, Bestmann S, Bikson M, Brewer CC, Brockmöller J, 
Carpenter LL, Cincotta M, et al. Safety and recommendations for TMS use in healthy subjects and 
patient populations, with updates on training, ethical and regulatory issues: Expert Guidelines. 
Clinical Neurophysiology. 2020;132(1):269–306. doi:10.1016/j.clinph.2020.10.003 
Fried PJ, Santarnecchi E, Antal A, Bartres-Faz D, Bestmann S, Carpenter LL, Celnik P, Edwards D, 
Farzan F, Fecteau S, et al. Training in the practice of noninvasive brain stimulation: 
Recommendations from an IFCN committee. Clinical Neurophysiology. 2021;132(3):819–837. 
doi:10.1016/j.clinph.2020.11.018 
 
 
Potential Benefits:  
This study has not been designed to benefit the individual participants. However, the results from this study 
might be used to develop future interventions using non-invasive brain stimulation. 
 
12.2. Assessment of Safety 
If the participant indicates a non-zero answer to the question about suicide on the PHQ-9, a psychiatrist or clinical 
psychologist will be consulted with regards to next steps. 
 
12.3. Unanticipated Problems, Adverse Events, Serious Adverse Events 
Unanticipated Problems:  
The Office for Human Research Protections (OHRP) considers unanticipated problems involving risks to 
participants or others to include, in general, any incident, experience, or outcome that meets all of the following 
criteria: 
 
• 
Unexpected in terms of nature, severity, or frequency given (a) the research procedures that are described 
in the protocol-related documents, such as the Institutional Review Board (IRB)-approved research protocol 
and informed consent document; and (b) the characteristics of the participant population being studied; 

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• 
Related or possibly related to participation in the research (“possibly related” means there is a reasonable 
possibility that the incident, experience, or outcome may have been caused by the procedures involved in 
the research); and 
• 
Suggests that the research places participants or others at a greater risk of harm (including physical, 
psychological, economic, or social harm) than was previously known or recognized. 
  
 
Adverse Event (AE) Definitions:  
Adverse event means any untoward medical occurrence associated with the use of an intervention in humans, 
whether considered intervention-related (21 CFR 312.32 (a)).  
 
 
Serious Adverse Events (SAE) Definition: <insert text>    
An adverse event (AE) or suspected adverse reaction is considered "serious" if, in the view of the investigator, 
it results in any of the following outcomes: death, a life-threatening adverse event, inpatient hospitalization or 
prolongation of existing hospitalization, a persistent or significant incapacity or substantial disruption of the 
ability to conduct normal life functions, or a congenital anomaly/birth defect. Important medical events that 
may not result in death, be life-threatening, or require hospitalization may be considered serious when, based 
upon appropriate medical judgment, they may jeopardize the participant and may require medical or surgical 
intervention to prevent one of the outcomes listed in this definition. Examples of such medical events include 
allergic bronchospasm requiring intensive treatment in an emergency room or at home, blood dyscrasias or 
convulsions that do not result in inpatient hospitalization, or the development of drug dependency or drug 
abuse. 
 
Grading the Severity of Adverse Events and Events of ‘Special Interest’:   
All adverse events (AEs) will be assessed by the principal investigator and/or co-investigator(s) using the 
following guidelines:  
 
• 
Mild – Events require minimal or no treatment and do not interfere with the participant’s daily activities.  
• 
Moderate – Events result in a low level of inconvenience or concern with the therapeutic measures. 
Moderate events may cause some interference with functioning. 
• 
Severe – Events interrupt a participant’s usual daily activity and may require systemic drug therapy or other 
treatment. Severe events are usually potentially life-threatening or incapacitating.  Of note, the term 
“severe” does not necessarily equate to “serious”. 
 
Relatedness Definition:  
All adverse events (AEs) must have their relationship to study intervention assessed by the principal investigator 
and co-investigator(s) who examines and evaluates the participant based on temporal relationship and their 
clinical judgment. The degree of certainty about causality will be graded using the categories below. In a clinical 
trial, the study product must always be suspect.  
 
• 
Definitely Related – There is clear evidence to suggest a causal relationship, and other possible contributing 
factors can be ruled out. The clinical event, including an abnormal laboratory test result, occurs in a 
plausible time relationship to study intervention administration and cannot be explained by concurrent 
disease or other drugs or chemicals. The response to withdrawal of the study intervention (dechallenge) 
should be clinically plausible. The event must be pharmacologically or phenomenologically definitive, with 
use of a satisfactory rechallenge procedure if necessary. 
• 
Probably Related – There is evidence to suggest a causal relationship, and the influence of other factors is 
unlikely. The clinical event, including an abnormal laboratory test result, occurs within a reasonable time 
after administration of the study intervention, is unlikely to be attributed to concurrent disease or other 

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drugs or chemicals, and follows a clinically reasonable response on withdrawal (dechallenge). Rechallenge 
information is not required to fulfill this definition. 
• 
Potentially Related – There is some evidence to suggest a causal relationship (e.g., the event occurred 
within a reasonable time after administration of the trial medication). However, other factors may have 
contributed to the event (e.g., the participant’s clinical condition, other concomitant events). Although an 
AE may rate only as “possibly related” soon after discovery, it can be flagged as requiring more information 
and later be upgraded to “probably related” or “definitely related”, as appropriate. 
• 
Unlikely to be related – A clinical event, including an abnormal laboratory test result, whose temporal 
relationship to study intervention administration makes a causal relationship improbable (e.g., the event 
did not occur within a reasonable time after administration of the study intervention) and in which other 
drugs or chemicals or underlying disease provides plausible explanations (e.g., the participant’s clinical 
condition, other concomitant treatments). 
Not Related – The AE is completely independent of study intervention administration, and/or evidence exists 
that the event is definitely related to another etiology. There must be an alternative, definitive etiology 
documented by the clinician. 
 
Expectedness Definition:  
The principal investigator, with input from the co-investigator when necessary, will determine whether an 
adverse event (AE) is expected or unexpected in this population. The principal investigator is an expert in non-
invasive brain stimulation and will provide his expert opinion regarding this as well. An AE will be considered 
unexpected if the nature, severity, or frequency of the event is not consistent with the risk information 
previously described for the study intervention. 
 
AE and SAE Assessment, Follow-up Procedures:   
The occurrence of an adverse event (AE) or serious adverse event (SAE) may come to the attention of study 
personnel during study visits, or the study participant may report AE or SAEs outside of a scheduled study visit. 
All AEs including local and systemic reactions not meeting the criteria for SAEs will be captured on the 
appropriate case report form (CRF). Information to be collected includes event description, time of onset, 
clinician’s assessment of severity, relationship to study product (assessed only by those with the training and 
authority to make a diagnosis), and time of resolution/stabilization of the event. All AEs occurring while on 
study must be documented appropriately regardless of relationship. All AEs will be followed to adequate 
resolution. Any medical condition that is present at the time that the participant is screened will be considered 
as baseline and not reported as an AE. However, if the study participant’s condition deteriorates at any time 
during the study, it will be recorded as an AE.   Changes in the severity of an AE will be documented to allow an 
assessment of the duration of the event at each level of severity to be performed. AEs characterized as 
intermittent require documentation of onset and duration of each episode.   
 
Reporting and Documentation Procedures:   
 
What event is reported When 
is 
event 
reported 
By whom is event 
reported 
To whom is event 
reported 
Fatal or life-threatening 
unexpected, suspected 
serious 
adverse 
reactions 
Within 24 hours of 
initial 
receipt 
of 
information 
Investigator 
Local/internal IRB 
Non-fatal, 
non-life-
threatening 
unexpected, suspected 
serious 
adverse 
reactions 
Within 48 hours of 
initial 
receipt 
of 
information 
Research Personnel 
Local/internal IRB 
 

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Unanticipated adverse 
device effects 
Within 10 working days 
of 
investigator 
first 
learning of effect  
Investigator 
Local/internal IRB 
 
Unanticipated Problem 
that is not an SAE 
Within 7 days of the 
investigator becoming 
aware of the problem 
Investigator 
Local/internal IRB 
 
 
 
Participant Notification of New Information: 
Any new information gained during the study that may affect a participant’s willingness to continue in the study 
will be reported to all currently enrolled participant. 
 
12.4. Safety Monitoring 
Research personnel will record all reportable events with start dates occurring any time after informed consent 
is obtained until the last day of study participation. At each study visit, research personnel will inquire about 
the occurrence of AE/SAEs since the last visit. All AEs including local and systemic reactions not meeting the 
criteria for SAEs will be captured on the appropriate case report form (CRF). Information to be collected includes 
event description, time of onset, clinician’s assessment of severity, relationship to study product (assessed only 
by those with the training and authority to make a diagnosis), and time of resolution/stabilization of the event. 
All AEs will be followed to adequate resolution. 
 
12.5. Study Suspension / Early Termination of the Study 
This study may be temporarily suspended or prematurely terminated if there is sufficient reasonable cause. If 
the study is prematurely terminated or suspended, the principal investigator will promptly inform research 
staff, study participants, and the IRB and will provide the reason(s) for the termination or suspension.  Study 
participants will be contacted, as applicable, and be informed of changes to study visit schedule.   
 
Circumstances that may warrant termination or suspension include, but are not limited to: 
• 
Determination of unexpected, significant, or unacceptable risk to participants 
• 
Insufficient compliance to protocol requirements 
• 
Data that are not sufficiently complete and/or evaluable 
 
Study may resume once concerns about safety, protocol compliance, and data quality are addressed, and satisfy 
the IRB. 
 
 
13. Regulatory, Ethical, and Study Oversight Specifications 
 
13.1. Informed Consent Process 
 
 
13.1.1. 
Consent/Assent and Documents Provided to Participants 

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Informed consent is a process that is initiated prior to the individual’s agreeing to participate in the study and 
continues throughout the individual’s study participation. Extensive discussion of risks and possible benefits of tACS 
will be provided to the participants.  
Consent forms describing in detail the study intervention, study procedures, and risks are given to the participant 
and written documentation of informed consent is required before visit 1.  
 
 
13.1.2. 
Consent Procedures and Documentation 
Informed consent is a process that is initiated prior to the individual’s agreeing to participate in the study and 
continues throughout the individual’s study participation. Consent forms will be Institutional Review Board (IRB)-
approved and the participant will be asked to read and review the document. The investigator will explain the 
research study to the participant and answer any questions that may arise. A verbal explanation will be provided in 
terms suited to the participant’s comprehension of the purposes, procedures, and potential risks of the study and 
of their rights as research participants.  Participants will have the opportunity to carefully review the written consent 
form and ask questions prior to signing. The participants have the opportunity to discuss the study with their family 
or surrogates or think about it prior to agreeing to participate. The participant will sign the informed consent 
document prior to any procedures being done specifically for the study. Participants must be informed that 
participation is voluntary and that they may withdraw from the study at any time, without prejudice. A copy of the 
informed consent document will be given to the participants for their records. The informed consent process will 
be conducted and documented in the source document (including the date), and the form signed, before the 
participant undergoes any study-specific procedures. The rights and welfare of the participants will be protected by 
emphasizing to them that the quality of their medical care will not be adversely affected if they decline to participate 
in this study. 
13.2. Study Discontinuation and Closure 
See sections 7.5 and 12.5. 
 
13.3. Confidentiality and Privacy 
Participant confidentiality and privacy is strictly held in trust by the participating investigators, their staff, and the 
research team. This confidentiality is extended to cover the clinical information relating to participants. Therefore, 
the study protocol, documentation, data, and all other information generated will be held in strict confidence.  In 
addition, all research activities will be conducted in an as private as possible setting. 
 
All data will only be referenced by dummy identifier code. Data will be stored on a password protected computer. 
A key connecting names and identifier code numbers will be kept in a locked cabinet, accessible only by research 
personnel. All data will be stored and analyzed on password protected computers, also only accessible by research 
personnel. Participants will not be identified in any report or publication about this study and there is no risk of 
deductive disclosure. At the end of the study, all records will continue to be kept in a secure location for as long a 
period as dictated by the IRB. 
 
Study participant research data, which is for purposes of statistical analysis and scientific reporting, will be entered 
into TraCS Clinical Research Data Management Service (REDCap). The database system provides secure web-based 
data entry with the data stored on servers that are maintained by TrACS. The data is encrypted during transmission. 
The servers are located in a secure campus area with all appropriate physical security measures in place. The web 
and database servers are monitored by the TraCS IT staff, patched frequently, and scanned by a third-party vendor 
to ensure that they are protected against known vulnerabilities. The scanning application is the standard service for 
the entire campus. Access is by individual user id and is restricted to the forms and/or functions that the user needs 
to have. 
  

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13.4. Future Use of Stored Specimens and Data 
Data collected for this study will be analyzed and stored within the Carolina Center for Neurostimulation/Frohlich 
Lab. After the study is completed, the data will be fully de-identified and archived within a locked file cabinet within 
the Carolina Center for Neurostimulation. 
 
13.5. Key Roles and Study Governance 
 
Principal Investigator 
 
Medical Monitor 
Flavio Frohlich, PhD 
 
Nathan Walker MD Assistant Professor of Neurology 
The University of North Carolina at Chapel Hill  
 
UNC – Chapel Hill  
Department of Psychiatry 
 
 
919-966-4584 
 
(919) 966-9343 
flavio_frohlich@med.unc.edu 
 
 nwalker@neurology.unc.edu 
 
 
13.6. Safety Oversight 
Safety oversight will be under the direction of the principal investigator. He will review all adverse events timely 
and serious adverse events and changes in the suicidality and mania ratings immediately. Based on his review, 
continuation of participant’s participation is decided. All SAE or unanticipated AE will be reported to the local IRB. 
13.7. Clinical Monitoring Plan (CMP) 
The purpose of the monitoring plan is to present the approach of the Carolina Center for Neurostimulation to 
monitoring clinical trials.  The plan facilitates compliance with good clinical practice. 
 
(a) The rights and well-being of human participants are protected. 
(b) The reported trial data are accurate, complete, and verifiable from source documents. 
(c) The conduct of the trial is in compliance with the currently approved protocol/amendment(s), with GCP, and 
with applicable regulatory requirement(s). 
 
This section identifies key monitoring activities and specifies the data to be reviewed over the course of a clinical 
trial.  This is a single site, investigator initiated, clinical trial so there will be no site monitoring plan in place. 
 
The Carolina Center for Neurostimulation monitoring plan:  
The latest version of the approved IRB application for this clinical trial will be followed at all times. This responsibility 
falls in the hands of the trained research personnel.  If at any time there is a deviation from protocol, the deviation 
form protocol log will be filled out. All team members will be trained on how and when to use this log.  
 
Data will be verified for completeness following every study session and all data will be entered into REDCap, a 
secure online database. After a participant has completed their participation (full completion through all visits or 
because they withdrew prior to completion), data will be rereviewed for completeness and accuracy. After all data 
has been collected, data will be re-reviewed by another lab member who was not involved with the data collection 
process.  
 

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AE and SAE are clearly defined in the Master Protocol. Documents of AE and SAE can be found in the study binder 
on file. It is responsibility of trained research personnel to report all events to the PI.  
 
The principal investigator will have read-only access to the REDCap database.  This allows the principal investigator 
to view reports that provide information on any missing data on an individual participant basis, but does not allow 
them to add, change or input any data. 
 
13.8. Quality Assurance and Quality Control  
The Carolina Center for Neurostimulation will conduct internal quality management of study conduct, data 
collection, documentation, and completion. Following written Standard Operating Procedures (SOPs), research 
personnel will verify that the clinical trial is conducted and data are generated and biological specimens are 
collected, documented (recorded), and reported in compliance with the protocol, International Conference on 
Harmonisation Good Clinical Practice (ICH GCP), and applicable regulatory requirements (e.g., Good Laboratory 
Practices (GLP), Good Manufacturing Practices (GMP)). 
 
13.9. Protocol Deviations 
All deviations from the protocol will be addressed in study participant source documents. The researcher will 
complete a Protocol Deviation Log using the participant code as the identifier. This form will collect information 
such as the date the deviation occurred, details of what the deviation consisted of, any corrective and preventative 
actions that were taken as a result of the deviation, and the date that the principal investigator and IRB were 
notified. The principal investigator will review the information and initial once approved. A completed copy of the 
Protocol Deviation Form will be maintained in the regulatory file, as well as in the participant’s source document. 
The site study staff will be responsible for knowing and adhering to their IRB requirements. 
 
13.10. Publication and Data Sharing Policy  
This study will comply with the NIH Data Sharing Policy and Policy on the Dissemination of NIH-Funded Clinical Trial 
Information and the Clinical Trials Registration and Results Information Submission rule. As such, this trial will be 
registered at ClinicalTrials.gov, and results information from this trial will be submitted to ClinicalTrials.gov. In 
addition, every attempt will be made to publish results in peer-reviewed journals.   
 
13.11. Conflict of Interest Policy 
The independence of this study from any actual or perceived influence is critical. Any conflict of interest for any 
persons who have a role in the design, conduct, analysis, publication, or any aspect of this trial will be disclosed and 
managed by the UNC Conflict of Interest Office. If necessary, for persons who have a perceived conflict of interest, 
management will be provided again by the UNC Conflict of Interest office. 
 
 

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14.Additional Considerations 
 
Not applicable.  
 
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