Targeting Individual Alpha Frequencies to Enhance Perceptual Timing

NCT04856657 | Completed

• 1 other identifier: PSYCH-2021-29530
• Study Type: observational
• Target: 11
• Locations: 1 country
• Sites: 1

Brief Summary

This is a single-blind randomized within-subject crossover design study that will be conducted in 2 phases. In Phase 1, up to 50 participants, after signing informed consent and determining eligibility, will undergo a baseline EEG and cognitive assessment. In Phase 2 participants will undergo tACS at IAF+2Hz, IAF-2Hz, and IAF during a double-flash illusion task in a randomized order. 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.

Conditions

Psychosis; Schizophrenia; Schizo Affective Disorder

Keywords

tacs; neuromodulation; psychosis; schizophrenia

Outcome Measures

Primary Outcomes (1)

• Double Flash Fusion Illusion Task

  Participants are instructed to fixate their gaze on a central fixation cross. When the cue appears, a low-luminance disc stimulus flashes on either side (left or right) of the fixation cross. The disc can flash one or two times. After the stimulus ends, participants are cued to make a response regarding the number of disc flashes (1 or 2). Participants will undergo 300 trials. Participants will be scored on response accuracy (i.e., number of correct responses out of 300 possible responses).

  2 20-minute task runs (one during tACS at IAPF + 2 Hz and one during tACS at IAPF - 2 Hz)

Study Arms (2)

Session 1: tACS at IAPF + 2 Hz

Participants in this arm will undergo tACS at a frequency 2 Hz above their IAPF during stimulation session 1. They will undergo tACS at a frequency 2 Hz below their IAPF during stimulation session 2.

Device: Transcranial alternating current stimulation

Session 1: tACS at IAPF - 2 Hz

Participants in this arm will undergo tACS at a frequency 2 Hz below their IAPF during stimulation session 1. They will undergo tACS at a frequency 2 Hz above their IAPF during stimulation session 2.

Device: Transcranial alternating current stimulation

Interventions

Transcranial alternating current stimulation DEVICE

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 anode will be located at Oz and the cathode will be located at Cz.

Also known as: tACS

Session 1: tACS at IAPF + 2 Hz; Session 1: tACS at IAPF - 2 Hz

Eligibility Criteria

• Age: 18 Years - 64 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

This study will study individuals who experience psychosis, including schizophrenia, schizoaffective disorder, and bipolar disorder with psychosis.

You may qualify if:

• Meet diagnostic criteria for a psychotic disorder (schizophrenia, schizoaffective disorder, schizophreniform disorder, major depressive disorder with psychotic features, bipolar disorder with psychotic features, psychosis disorder not otherwise specified, or unspecified schizophrenia spectrum disorder), as defined by the MINI (Mini-International Neuropsychiatric Interview)
• Are age 18-64 (inclusive)
• Fluent in written and spoken English
• Have an outpatient status of at least 1 month prior to participation
• Has been on a stable dose of psychiatric medication for at least one month prior to participation (titration to a lower dose of psychotropic medications under supervision of a psychiatrist can be allowed at the discretion of the investigators)

You may not qualify if:

• History of seizures or epilepsy
• Metallic cranial plates, screws, or implanted devices
• History of craniotomy
• History of stroke
• History of eczema on scalp
• Pre-existing sores or lesions at sites of tACS electrode placement
• Non-removable facial piercings
• Current or possibility of current pregnancy
• Active suicidal ideation at screening or baseline assessments, or previous intent to act on suicidal ideation with a specific plan, preparatory acts, or an actual suicide attempt within the last 3 months, as indicated by the MINI and/or C-SSRS (All participants will complete the suicide module of the MINI. If participants express any suicidal ideation on the MINI, staff will complete the C-SSRS \[Columbia-Suicide Severity Rating Scale\].)
• WTAR (Wechsler Test of Adult Reading) standardized score below 70
• Any reason our tCS (transcranial stimulation) or EEG caps cannot be placed on their head
• Control Participants:
• Are age 18-64 (inclusive)
• Fluent in written and spoken English
• Meet diagnostic criteria for a psychotic disorder (schizophrenia, schizoaffective disorder, schizophreniform disorder, major depressive disorder with psychotic features, bipolar disorder with psychotic features, psychosis disorder not otherwise specified, or unspecified schizophrenia spectrum disorder), as defined by the MINI

Sponsors & Collaborators

• University of Minnesota: lead

Study Sites (1)

University of Minnesota

Minneapolis, Minnesota, 55455, United States

Location

MeSH Terms

Conditions

Psychotic Disorders; Schizophrenia; Spondylocostal Dysostosis 4, Autosomal Dominant

Interventions

Transcranial Direct Current Stimulation

Condition Hierarchy (Ancestors)

Schizophrenia Spectrum and Other Psychotic Disorders; Mental Disorders

Intervention Hierarchy (Ancestors)

Electric Stimulation Therapy; Therapeutics; Convulsive Therapy; Psychiatric Somatic Therapies; Behavioral Disciplines and Activities; Electroshock; Psychological Techniques

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 13, 2021
• First Posted: April 23, 2021
• Study Start: November 1, 2021
• Primary Completion: February 9, 2023
• Study Completion: February 9, 2023
• Last Updated: February 14, 2023

Record last verified: 2023-02

Locations

US (1)