tACS for Self-Other Boundary in Schizophrenia
Recruiting · NCT07818668 · Interventional (participants receive a specific treatment)
View the official record on ClinicalTrials.gov →Interventions studied
What this trial is about
This clinical trial investigates whether a non-invasive brain stimulation technique called transcranial alternating current stimulation (tACS) can improve the ability to distinguish between "self" and "others" in patients with schizophrenia. The intervention targets the medial prefrontal cortex (mPFC), a brain region critical for self-awareness, using 10Hz stimulation at 2mA for 20 minutes daily over five consecutive days. The study has two main objectives. First, it aims to characterize the underlying mechanisms of self-other boundary dysfunction in schizophrenia by comparing behavioral and brain activity patterns among three participant groups: patients with schizophrenia, individuals with high schizotypal traits, and healthy volunteers. During this mechanism phase, participants perform two computer-based self-other face recognition tasks designed to manipulate prior probability (varying the proportion of self vs. other faces across blocks) and perceptual uncertainty (adjusting the Gaussian blur level of face images), while their brain activity is recorded via EEG. Behavioral performance (response time, accuracy, and sensitivity d') and EEG markers (alpha-band power, N170, and P1 components) are analyzed to quantify deficits in predictive coding. Second, the study aims to evaluate the therapeutic efficacy of tACS in a randomized, double-blind, sham-controlled trial. The primary hypothesis is that active tACS, compared to sham stimulation, will significantly improve patients' accuracy in distinguishing self from other faces, accompanied by enhanced alpha-band brain oscillations and reduced scores on the Examination of Anomalous Self-Experience (EASE) scale. All participants will undergo clinical assessments, complete the face recognition tasks while their brain activity is monitored via EEG, and complete follow-up assessments 48 hours after the last stimulation session. The findings from this study may provide a novel, mechanism-based non-pharmacological intervention for addressing core self-disturbance in schizophrenia, potentially improving patients' social functioning and quality of life.
Who can take part
Inclusion criteria
- Diagnosis of schizophrenia according to DSM-5 criteria
- Presence of hallucinations or delusions
- Age between 18 and 50 years
- Clinically stable on a stable dose of antipsychotic medication for at least 4 weeks prior to enrollment, with no anticipated medication changes during the study period
- Normal or corrected-to-normal vision (≥ 20/40) as assessed by standard visual acuity test
- Able to understand and provide written informed consent
Exclusion criteria
- History of neurological disorders (e.g., epilepsy, stroke, traumatic brain injury)
- Presence of other major psychiatric disorders (e.g., bipolar disorder, major depressive disorder)
- Previous receipt of non-invasive brain stimulation (e.g., tACS, tDCS, rTMS)
- History of substance dependence or abuse within the past 6 months
- Metal implants in the head or skull (e.g., cochlear implants, deep brain stimulators)
- Pregnancy or breastfeeding
- Presence of skin lesions, wounds, or sensitive skin at electrode placement sites (Fpz, AF7, AF8, F5, F6)
Where it is running
1 location listed.
- The Fourth People's Hospital of Hefei - Hefei, Anhui, China