The Effects of tDCS on the Neuronal Mechanisms of Cognitive Control in Schizophrenia

Not Applicable

Terminated

• Conditions: Schizophrenia
• Interventions: Device: Transcranial Direct Current Stimulation

• Registration Number: NCT03077347
• Lead Sponsor: University of California, Davis

Brief Summary

The purpose of this study is to better understand the neural correlates of cognitive control (CC) deficits in schizophrenia and determine how these mechanisms can be modulated by transcranial direct current stimulation (tDCS). CC is a critical neurocognitive process that is required for flexible, directed thought and action based on goals and intentions. Identifying and developing paradigms to improve CC is therefore a mental health priority. Current theories of CC postulate that recruitment of the dorsolateral prefrontal cortex (DLPFC) is essential for this process by maintaining high-level information that it can then use to orchestrate patterns of activation in other brain networks to support optimal performance. tDCS is a safe, noninvasive method of modulating regional brain excitability via brief (15-20 m) application of a weak (1-2 mA) current. The goal of the proposed experiments is to combine tDCS with functional magnetic resonance imaging (fMRI) to test the hypotheses that 1) acute tDCS over the DLPFC can improve performance during a CC task (the dot pattern expectancy (DPX) variant of the AX-Continuous Performance Task) in schizophrenia patients and healthy control subjects, and 2) acute tDCS over the DLPFC can increase recruitment of the DLPFC during the DPX. Effects of tDCS on brain functional connectivity (during CC as well as during the resting state) will also be examined, as well as effects on an episodic memory task. The current study will be the first to use functional magnetic resonance imaging (fMRI) to examine the effects of tDCS on the neuronal mechanisms of CC in schizophrenia, and has potentially important implications for therapeutic development for this treatment refractory yet disabling aspect of the illness.

Detailed Description

Not available

Basic Information
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Recruitment & Eligibility
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Study & Design
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Trial Locations

Study Timeline

• Study First Submitted: 2017-03-01
• Study First Submitted QC: 2017-03-06
• Study First Posted: 2017-03-10
• Study Start: 2017-04-01
• Primary Completion: 2023-02-23
• Study Completion: 2023-02-23
• Status Verified: 2023-10
• Results First Submitted: 2024-03-26
• Results First Submitted QC: 2024-05-18
• Last Update Submitted: 2024-05-18
• Results First Posted: 2024-06-13
• Last Update Posted: 2024-06-13

Recruitment & Eligibility

• Status: TERMINATED
• Sex: All
• Target Recruitment: 6

Inclusion Criteria

Not provided

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Exclusion Criteria

Not provided

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Experimental Stimulation Followed by Sham	Transcranial Direct Current Stimulation	Experimental stimulation administered followed by 24-48 hour washout, then sham stimulation. Experimental Intervention. 20 minutes of 2 mA direct current stimulation over the dorsolateral prefrontal cortex Placebo Comparator. 1 minute of 2 mA direct current stimulation over the dorsolateral prefrontal cortex followed by 19 minutes of sham stimulation.
Sham Followed by Experimental Stimulation	Transcranial Direct Current Stimulation	Sham stimulation administered followed by 24-48 hour washout, then experimental stimulation. Experimental Intervention. 20 minutes of 2 mA direct current stimulation over the dorsolateral prefrontal cortex Placebo Comparator. 1 minute of 2 mA direct current stimulation over the dorsolateral prefrontal cortex followed by 19 minutes of sham stimulation.

Primary Outcome Measures

Name	Time	Method
Behavioral Response	Assessment will begin immediately following stimulation and last for up to an hour.	Cognitive control-related performance (d-prime context) associated with the task (Dot-Probe Expectancy Task).; The d-prime context index was calculated by computing a d-prime index from hits on AX trials and false alarms on BX trials as Z(H) - Z(F), with H representing hits on AX trials, F representing false alarms on BX trials, and Z representing the z-transform of a value.; Positive d-prime values indicate more cognitive control, and negative values indicate less cognitive control.
Dorsolateral Prefrontal Cortex Response	Assessment will begin immediately following stimulation and last for up to an hour.	Blood oxygen level-dependent response of the dorsolateral prefrontal cortex during a cognitive control task (Dot-Probe Expectancy Task)

Trial Locations

Locations (1)

Imaging Research Center, University of California Davis Medical Center; 🇺🇸 Sacramento, California, United States