Targeting Individual Alpha Frequencies to Enhance Perceptual Timing

Summary

Participation Requirements

Description

The proposed pilot study will assess the feasibility of transcranial alternating current stimulation (tACS) to enhance aspects of attention in people with psychotic disorders. If a participant agrees to participate in this research, they will be asked to visit the study site to complete the activiti...

The proposed pilot study will assess the feasibility of transcranial alternating current stimulation (tACS) to enhance aspects of attention in people with psychotic disorders. If a participant agrees to participate in this research, they will be asked to visit the study site to complete the activities listed below. These study activities will take about 5.5 hours to complete. The activities can be divided into up to 3 separate sessions as needed, but all activities should be completed within approximately one week. Consent (30 minutes): The study team will review this consent form with the participant. If they agree to participate in this research, they will sign and date the consent form. They will receive a copy of the signed consent form for your records. Baseline clinical assessments (60-90 minutes): Participants will be asked to complete interviews and assessments to test their cognition and to confirm any diagnoses of psychosis or mood disorders. They will also be asked to complete a demographics questionnaire. The psychosis group will be asked to complete an additional clinical assessment and will receive additional compensation accordingly. Electroencephalogram (EEG, 120 minutes): After study staff set up the gel-filled EEG cap on the participant's head, they will be asked to complete a few tasks on the computer. tACS with Double-Flash Fusion Illusion task (90 minutes): The participant will undergo 2 runs of a computerized task while simultaneously undergoing tACS stimulation. The tACS setup involves a neoprene cap (like a swim cap) with two electrodes covered by saline-soaked sponges. The stimulation system will deliver a small amount of electrical current through the saline-soaked sponges. Each task run is expected to last about 15-20 minutes, with a 40-minute break between sessions. During this break, you will be asked to perform two computerized BrainHQ tasks that look at your auditory and visual perception. After both sessions are complete, you will complete a questionnaire about the stimulation procedure and whether you experienced any adverse effects. One tACS session will be set to 2 Hz above the participant's individual alpha peak frequency (IAPF) and the other session will be set to 2 Hz below the participant's IAPF. The tACS will be applied with a current of 1-2 mA (milliamperes) via two saline soaked electrode sponges (25 cm²) applied to the back of the head. The investigator's hypothesis is that participant's will perform better on the visual task while tACS is set to 2 Hz above their IAPF, relative to tACS set to 2 Hz below their IAPF.

Tracking Information