Clinical trial NCT03319134: Investigating the Neural Correlates in Memory Retrieval After HD-tDCS
Official title: Investigating the Neural Correlates in Memory Retrieval After HD-tDCS
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Healthy Adults
Lead sponsor: The University of Texas at Dallas
Sponsor class: OTHER
First posted: 2017-10-24
Enrollment: 45
Sex: ALL
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Participants will be randomly assigned to one of three groups: (1) active HD-tDCS with retrieval memory task, (2) sham HD-tDCS with retrieval memory task, (3) active cathodal HD-tDCS with retrieval memory task
Primary purpose: BASIC_SCIENCE

Brief summary: The overall objective of this study is to investigate the neural correlate in retrieval memory task.

The aim of the study is to understand the undergoing changes in late positive ERP component during retrieval memory task when stimulating the posterior cingulate cortex (PCC) with High Definition Transcranial Direct Current Stimulation (HD-tDCS).

Detailed description: Retrieval memory is supported by distinct retrieval process known as recollection and familiarity. These two process have been associated with distinct event related potentials (ERPs). At the time of retrieval, familiarity is associated with modulation of the FN400, an enhanced positivity for old items relative to new items observed from approximately 400-600ms post stimulus onset. The FN400 tends to have mid-frontal scalp distribution which can extend to left and right frontal areas and central midline regions. In contrast, recollection has been linked with modulation of positive going waveform that emerges approximately 600ms post stimulus and is typically maximal over parietal sites and referred to as late positive component (LPC). In addition, FN400 is found to increase gradually as a function of item retrieval confidence whereas LPC is limited to high confidence retrieval response.

High Definition transcranial Direct Current Stimulation (HD-tDCS ) is a non-invasive neuromodulation technique. Compared to the standard bipolar montage used by the conventional tDCS, it uses arrays of smaller, specially designed electrodes to deliver a constant and low current directly to the cortical brain areas to increase the spatial focality. Studies show that the cortical area undergoing stimulation with HD-tDCS is more restricted compared to the standard bipolar montage of conventional tDCS. Moreover, tDCS has been proposed as a therapeutic procedure in various diseases and tDCS in healthy adults have demonstrated to improve cognitive and memory performance, but information regarding the effects of HD-tDCS targeting the PCC and its impact on memory retrieval is scarce. By targeting the PCC area by HD-tDCS, we want to introduce a safer, easier-to-use and more accurate non-invasive neuromodulation procedure. The dysfunctions of posterior cingulate cortex hav been linked to a range of psychiatric and neurological condition such as Alzheimer's disease, schizophrenia, autism, depression and attention deficit hyperactivity disorder, as well as aging. It shows increased activity when subject retrieve autobiographical memories suggests its internal orientated function. PET and ERP combined studies have shown greater blood flow medial temporal lobe with a brief late positive ERP component in PCC. Therefore, in this study we aim to understand whether HD-tDCS targeting the PCC can modulate the late positive ERP component.

Eligibility criteria: Inclusion Criteria:

* Native English Speaker
* Currently not using any medication
* Capable of understanding and signing an informed consent

Exclusion Criteria:

* Severe disease
* Mental illness
* Cardiac history
* History of severe head injuries
* History of epileptic seizures
* Any implanted devices such as pacemaker, neurostimulator
* Pregnancy

Primary outcomes:
measure: Recognition Memory Assessed by a Retrieval Memory Experiment
timeFrame: Retrieval Memory is assessed after 90 seconds break following the recognition phase.
Secondary outcomes:
Other outcomes:
Locations:
city: Richardson
country: United States
facility: University of Texas at Dallas
state: Texas
Study officials:
affiliation: The University of Texas at Dallas
name: Sven Vanneste
role: PRINCIPAL_INVESTIGATOR
References: