Eardream Data Collection in Switzerland Supported by ADDF

Study Overview
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Brief Summary
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data collection based on this study will allow us to collect and calibrate neurophysiological and cognitive data collected from in-ear EEG recordings of the initial baseline/reference population in Swiss healthy individuals that can be used as reference to data collected in other populations, for instance, to be compared with any other similar dataset in the future (e.g., Alzheimer patient cohorts).

Detailed Description
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There is solid neurophysiological evidence indicating that abnormal brain rhythms during sleep and noradrenergic dysfunction are core components of cognitive decline and AD onset, and their related pathophysiology. Crucially, irregularities in these neurophysiological mechanisms appear to occur in an asymptomatic and pre-symptomatic stage, but their potential to identify susceptibility for triggering neurodegeneration has yet to be established. Thus, the possibility to identify such risk biomarkers in humans will require the acquisition of large-scale data related direct or indirect measurements of these physiological signatures. A possible key source to obtain such large-scale data related to sleep and noradrenergic function is the assessment of electroencephalographic recordings through non-obtrusive, low-cost, and reliable wearable sensors, alongside the use of advanced neuro-computational algorithms that link brain function and behavioral outcomes of LC function via pupilometry measurements.

Official Title
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Brain Oscillations, Sleep, and Arousal in Human Cognition

Conditions
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Healthy Aging

Intervention / Treatment
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* Other: This is an observational study


Participation Criteria
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Eligibility Criteria
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Participants fulfilling all of the following inclusion criteria are eligible for the study: Informed Consent as documented by signature Healthy young adults group: Age range 20-40 Healthy older adults group: Age range 50-75 Normal physical and mental status: Diseases or lesions of the nervous system (acute or residual included neurological and psychiatric diseases) Clinically significant concomitant disease states (e.g., renal failure, hepatic dysfunction, cardiovascular disease, etc.) Sleep disorders, known or suspected (e.g. Insomnia, sleep apnoea, restless leg syndrome, narcolepsy, etc.) mini mental state examination (MMSE) score > 24) Native German speaker or good understanding of German Participants are not eligible if the fulfil the following exclusion criteria: Direct relatives have not been diagnosed with neuropathological conditions associated with any form of dementia (e.g., AD, MCI) Participation in another study with investigational drug/therapy/interventions within the 30 days preceding and during the present study (start date adapted accordingly) Shift-work (e.g. work times 12am-5am) Suspected drug- or medication abuse, or on-label sleep medication use during time of the study Infection/disease of auditory canal or ear drum that could worsen with EAR-DREAM application, or allergies to in-Ear electrode materials (e.g., silver) Pregnancy (not safety related, but relevant for data interpretation procedures given that pregnancy can result in sleep patterns that are different from the baseline measurements that we intend to characterize) Additional non-medical exclusion criteria may be defined for certain cognitive tasks (e.g. no glasses during experiments involving pupillometry).

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| healthy young adults<br>between 20-40 years | Other: This is an observational study<br>* This is an observational study<br>|
| healthy older adults<br>between 50-75 years | Other: This is an observational study<br>* This is an observational study<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Density of slow-wave activity (SWA) readout from in-ear EEG recordings | in-ear EEG will be monitored during 7 nights, the aggregated density of SWA over the 7 nights will be compared in both groups (young vs elderly) | 7 nights of at-home recordings | 
| Relative phasic pupilometry responses in exploration vs exploration states in the cognitive task | latent variables of the LC-noradrenergic neuro-computational model based on our cognitive task will indicate the state in wich the participant is (exploration vs exploitation). The relative phasic pupilometry responses in these two states will serve as a proxy of the degree of LC-noradrenergic reaction to these states. The relative reactivity will be compared in both groups (young vs elderly) | 1 experimental session | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Power changes of wake EEG brain activity in close vs open eyes condition | We will compute the relative changes of EEG power in close vs open eyes. The relative changes will be compared in both groups (young vs elderly) | 7 days of at-home recordings | 
| Relative time-frequency decomposition responses in exploration vs exploration states in the cognitive task measured with EEG | We will evaluate the the differences spatio-temporal changes in the power spectrum depending on the state in wich the participant is (exploration vs exploitation) in the cognitive task. The relative changes will be compared in both groups (young vs elderly) | 1 experimental session |