Healthy Volunteers
Conditions
Keywords
Regular nap taker
Brief summary
The goal of this clinical trial is to find out whether stimulating the brain with electrical current during naps can increase certain kinds of brain activity that happen during sleep and lead to improvements in emotional health and stress resilience. Participants will attend up to 3 study visits, each of which may last up to 4-5 hours. During these visits, participants will wear a high density electroencephalography (hdEEG) cap and take a nap.
Detailed description
This is a single-blind, two-phase study. In the first phase, each participant will be assigned a nap length, a trigger region, a stimulation type (difference frequency, multipolar transcranial electrical stimulation with temporal interference (TES-TI), or phase modulation), and a stimulation start time relative to the appearance of spindles and sawtooth waves in their EEG. These parameters will be varied across and within participants who may undergo multiple naps in order to identify optimal parameters for enhancing REM sleep. Phase II is a single-blind study comprised of 40 participants. Each participant will undergo two 90-minute naps with possible sham or non-sham stimulation conditions. The naps will be on 2 separate visits to the lab with at least 1 week between visits. Conditions on each visit are randomized and counterbalanced. During each visit, participants will complete both the REST-Q and SSS questionnaires. Full HDEEG will be applied as well as 4-16 stimulation electrodes. Participants will then undergo an emotion regulation task (face task) wherein they are presented with positive, negative, or neutral emotional stimuli. This is followed by a resting EEG recording, then a nap up to 90 minutes in duration. Either sham or non-sham stimuli will be applied at times during the nap period. Upon waking, the same questionnaires and emotion regulation tasks will be completed.
Interventions
TES-TI uses specific electrode arrangement patterns to selectively stimulate the brain. Participants will wear an hdEEG (high density electroencephalography) cap which will allow intermittent periods of stimulation from TES-TI.
Sponsors
University of Wisconsin, Madison
United States Department of Defense
Study design
Allocation
RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Adults aged 18-50 years * Medically healthy * English-speaking (able to provide consent and complete questionnaires) * Citizen or holding permanent resident status * Regular napper (1 or more naps per week)
Exclusion criteria
* Any current or past history of neurological disorders or acquired neurological disease (e.g. stroke, traumatic brain injury), including intracranial lesions * History or head trauma resulting in prolonged loss of consciousness; or a history of \>3 grade 1 concussions * Current history of poorly controlled headaches including intractable or poorly controlled migraines * Any systemic illness or unstable medical condition that may cause a medical emergency in case of a provoked seizure (cardiac malformation, cardiac dysrhythmia, asthma, etc) * History of seizures, diagnosis of epilepsy, histoy of abnormal (epileptiform) EEG, or family history of treatment resistant epilepsy with the exception of a single seizure of benign etiology (e.g. febrile seizures) in the judgment of a board-certified neurologist * Possible pregnancy or plan to become pregnant in the next 6 months * Any metal in the body * Any medical devices or implants (i.e. cardiac pacemaker, medication infusion pump, cochlear implant, vagal nerve stimulator) unless otherwise approved by the responsible MD * Dental implants containing metal * Any medication that may alter seizure threshold: ADHD stimulants (Adderall, amphetamine); tricyclic/stypical antidepressants (amitriptyline, doxepine, imipramine, maprotiline, nortriptyline, buproprion); antipsychotics (chlorpromazine, clozapine); bronchodilators (theophylline, aminophylline); antibiotics (fluoroquinolones, imipenem, penicillin, cephalosporins, metronidazole, isoniazid); Antivirals (valacyclovir, ritonavir); OTC antihistamines (diphenhydramine, Benadryl) * Claustrophobia (a fear of small or closed places) * Back problems that would prevent lying flat for up to two hours * Regular night-shift work (second or third shift)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in spindles after effective TES-TI intervention | Post nap (up to 90 minutes) | Changes in sleep spindle density during sleep as measured by portable EEG device. |
| Identify effective TES-TI parameters to trigger spindles | Post nap (up to 90 minutes) | Researchers will do a power analysis on high density EEG data for spindle frequency (11-15Hz) and see if there is increase in this frequency range during/post stimulation. |
| Identify effective duration of the nap to maximize TES-TI effect on REM sleep | Post nap (up to 90 minutes) | Researchers will compare the durations of nap (sleep duration on the EEG) within subjects across their multiple visits, as well as across subjects; correlating this with the stimulation parameters |
| Change in sawtooth waves after effective TES-TI intervention | Post nap (up to 90 minutes) | Researchers will do a power analysis on high density EEG data for sawtooth wave frequency (3-5Hz) and see if there is increase in this frequency range during/post stimulation. |
| Change in score for vigilance task | Baseline to post-nap (up to 90 minutes) | The vigilance task is a computerized reaction time task where participants are presented with a fixation point on a computer screen. At random, the fixation point will change appearance at which point the participant is to click a provided button as quickly as possible. The latency response is recorded automatically. Faster responses are indicative of higher vigilance. |
| Change in sleep quality and mood | Baseline to post-nap (up to 90 minutes) | Sleep quality and mood will be assessed using the Restorative Sleep Questionnaire (REST-Q), a 9-item questionnaire assessing aspects of restorative sleep. Each item is scored on a 5-point Likert scale, scores range from 9-45. A higher score indicates a more restorative sleep |
| Change in sleepiness | Baseline to post-nap (up to 90 minutes) | Sleepiness will be measured using the Stanford Sleepiness Scale (SSS). SSS is a measure of subjective alertness on a 7-point scale. A lower score on the scale indicated higher alertness. |
| Change in emotion response | Baseline to post-nap (up to 90 minutes) | Emotional response is measured using an emotional processing task. This task involves viewing a series of emotionally charged images (60 positive, 60 negative, 60 neutral). Participants see a randomized set of these images and are asked to evaluate how pleasant and emotionally arousing each image is on respective 9-point Likert scales |
| Change in Spectral Power in Sawtooth Wave Frequency (3-5Hz) | Baseline to 4 weeks | — |
| Change in minutes scored as REM sleep | Baseline to 4 weeks | EEG data will be recorded during sleep. The sleep EEG data is separated into stages (REM-NREM). This way, it is known how many minutes they spend in each stage. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORGiulio Tononi, PhD
University of Wisconsin, Madison
Outcome results
None listed