Confirmatory Trial of Gamma Neurofeedback to Improve Working Memory in Schizophrenia

May 11, 2026 updated by: Fiza Singh, University of California, San Diego

Confirmatory Efficacy Trial to Confirm the Effects of Gamma EEG-Neurofeedback on Working Memory in Schizophrenia

This study is a confirmatory, double-blind, placebo-controlled randomized clinical trial (RCT) testing whether gamma EEG neurofeedback (EEG-NFB) improves working memory in adults with schizophrenia or schizoaffective disorder. Participants are randomly assigned to receive either active gamma EEG-NFB (real-time feedback of frontal gamma brain activity) or sham EEG-NFB (false pre-recorded feedback), twice weekly for 12 weeks. Working memory (N-back task), brain gamma coherence, and everyday community functioning are assessed at baseline, mid-treatment, end of treatment, and follow-up.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Schizophrenia is associated with deficits in gamma frequency (30-45 Hz) neural synchrony and working memory that are resistant to antipsychotic treatment. EEG neurofeedback (EEG-NFB) targeting frontal gamma coherence is a non-invasive approach that may restore gamma synchrony and improve working memory by reinforcing endogenous neural oscillations in real time.

This confirmatory RCT builds on a successful pilot trial (R33) demonstrating feasibility and preliminary efficacy of gamma EEG-NFB in schizophrenia. Participants (N=104) are randomized 1:1 to active gamma EEG-NFB or sham EEG-NFB. Active EEG-NFB delivers real-time feedback of frontal gamma coherence (F3/F4, 30-50 Hz) via a CGX wireless headset. Sham participants undergo identical procedures but receive pre-recorded feedback unrelated to their own brain activity. Both groups complete 30 sessions over 12 weeks (two sessions per week).

Co-primary outcomes are working memory (N-back d-prime) and frontal gamma coherence, assessed at baseline and Week 12. Secondary outcomes include global cognition, symptoms (PANSS), negative symptoms (CAINS), and community functioning (ILSS, UPSA-Brief, SFS). Follow-up assessments are conducted at 3 months (Week 24) and 6 months (Week 36) post-treatment. Primary analysis uses mixed model repeated measures (MMRM).

Study Type

Interventional

Enrollment (Estimated)

104

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • 1. DSM-5 diagnosis of schizophrenia or schizoaffective disorder, confirmed by the Structured Clinical Interview for DSM-5 (SCID-5) 2. Age 18-55 years 3. Clinically stable: no psychiatric hospitalization in the 3 months prior to enrollment 4. No change in antipsychotic medication type or dosage within 4 weeks prior to baseline assessment 5. Ascertained to be clinically and medically stable by a study investigator 6. Does not meet DSM-5 diagnostic criteria for bipolar disorder or current major depressive episode 7. No electroconvulsive therapy (ECT) within 6 months of baseline assessment 8. Able to read and speak English (corrected vision or hearing aids acceptable) 9. Able and willing to provide written informed consent

Exclusion Criteria:

  • 1. Self-reported history of seizure disorder 2. Diagnosed with multiple sclerosis 3. History of stroke or major vascular disease, including insulin-dependent diabetes mellitus 4. HIV/AIDS diagnosis 5. Current (not past) major depressive episode 6. Substance use disorder other than nicotine use disorder or caffeine use disorder in the past year 7. Brain cancer (primary or metastatic) 8. Prior head injury involving loss of consciousness 9. Inability to read or speak English 10. Color blindness that interferes with administration of study assessments 11. Neuropsychological or cognitive testing in the past 6 months using the same measures as this study 12. Score on Letter-Number Sequencing greater than 1 standard deviation above the age-normed mean

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Gamma EEG-NFB
Participants receive real-time gamma EEG neurofeedback targeting frontal gamma coherence (F3 and F4 electrodes, 30-50 Hz) via a CGX wireless 32-electrode headset. Each session includes a 1-minute resting baseline followed by two 15-minute training blocks. Positive reinforcement (images and music) is contingent on meeting an individualized gamma coherence threshold. Sessions are twice weekly for 12 weeks (30 total sessions).
Behavioral: EEG Neurofeedback
Gamma EEG neurofeedback delivered via CGX/Cognionics wireless headset (FDA cleared for research use). Active arm receives real-time gamma coherence feedback; sham arm receives pre-recorded feedback unrelated to own brain activity.
Other Names:
  • EEG NFB
Sham Comparator: Sham EEG-NFB
Participants undergo identical procedures to the active arm including EEG electrode placement and the same session structure, twice weekly for 12 weeks. However, the feedback displayed is pre-recorded from prior participants and has no relationship to the participant's own brain activity. Participants and outcome assessors are blinded to group assignment.
Behavioral: EEG Neurofeedback
Gamma EEG neurofeedback delivered via CGX/Cognionics wireless headset (FDA cleared for research use). Active arm receives real-time gamma coherence feedback; sham arm receives pre-recorded feedback unrelated to own brain activity.
Other Names:
  • EEG NFB

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
N-back 2-back target accuracy (d-prime)
Time Frame: Baseline to Week 12
Working memory performance on the N-back task (2-back condition), analyzed with mixed model repeated measures (MMRM).
Baseline to Week 12
Frontal gamma coherence during N-back task
Time Frame: Baseline to Week 12
EEG-derived frontal gamma coherence (30-50 Hz, F3-F4) measured during 2-back task performance.
Baseline to Week 12
Independent Living Skills Survey (ILSS) total score
Time Frame: Baseline to Week 12
Functional outcome assessing independent living skills relevant to community functioning.
Baseline to Week 12

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of California, San Diego

Investigators

  • Principal Investigator: Fiza Singh, MD, University of California, San Diego

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

June 1, 2026

Primary Completion (Estimated)

November 30, 2029

Study Completion (Estimated)

May 31, 2030

Study Registration Dates

First Submitted

May 11, 2026

First Submitted That Met QC Criteria

May 11, 2026

First Posted (Actual)

May 18, 2026

Study Record Updates

Last Update Posted (Actual)

May 18, 2026

Last Update Submitted That Met QC Criteria

May 11, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • R01MH139831

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data will be shared via the NIMH Data Archive (NDA) in accordance with the NIH Data Management and Sharing Plan submitted with R01MH139831. Data will be made available no later than the time of primary results publication.

IPD Sharing Time Frame

Within 12 months of primary results publication (estimated 2031)

IPD Sharing Access Criteria

De-identified individual participant data and supporting documents will be available to qualified researchers who submit a data access request through the NIMH Data Archive (NDA) at https://nda.nih.gov. Requestors must complete a Data Use Certification (DUC) agreeing to conditions of use including protecting participant confidentiality, not attempting to re-identify participants, and not sharing data outside the approved research team. Access is reviewed and approved by the NDA Data Access Committee.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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