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Effects of PFC tDCS on Cognitive Control, Attention Lapses and Coordinated Neural Activity in the Theta and Alpha Bands

Not Applicable
Recruiting
Conditions
Healthy
Interventions
Device: Transcranial Direct Current Stimulation
Registration Number
NCT04885322
Lead Sponsor
University of California, Davis
Brief Summary

The purpose of this study is to better understand the neural correlates of higher-order cognition, both in the healthy brain and in schizophrenia, and to determine how these mechanisms are modulated by transcranial direct current stimulation (tDCS) at frontal and occipital scalp sites. Testing the effects of tDCS at these scalp sites on cognitive task performance will help us understand the roles of the brain regions corresponding to these sites during higher-order cognitive processing (language comprehension, cognitive control, and related attention and memory processes). Behavioral and electrophysiological (EEG) measures will be used to assess cognitive performance. Our overarching hypothesis is that stimulating prefrontal circuits with tDCS can improve cognitive control performance, and ultimately performance on a range of cognitive tasks, as compared to stimulating a different cortical region (occipital cortex) or using sham stimulation.

This study is solely intended as basic research in order to understand brain function in healthy individuals and individuals with schizophrenia. This study is not intended to diagnose, cure or treat schizophrenia or any other disease.

Detailed Description

Not available

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
75
Inclusion Criteria
  • between ages of 18 and 50
  • ability to sufficiently speak and understand English so as to be able to understand and complete cognitive tasks
  • ability to give valid informed consent
Exclusion Criteria
  • no history of head trauma
  • no current or previous history of treatment with psychotropic medication
  • corrected vision 20/30 or better
  • tDCS/MRI contraindications, including: pregnancy, ferrous metal in any part of the body, serious medical conditions, claustrophobia, metallic implants, skin damage, conditions such as eczema at electrode sites, cranial pathologies

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
DLPFC StimulationTranscranial Direct Current StimulationIntervention. 20 minutes of 2 mA direct current stimulation over the dorsolateral prefrontal cortex.
Occipital StimulationTranscranial Direct Current StimulationIntervention. 20 minutes of 2 mA direct current stimulation over the occipital cortex.
Sham StimulationTranscranial Direct Current StimulationPlacebo Comparator. 0.5-1 minutes of 2 mA direct current stimulation over the dorsolateral prefrontal cortex followed by 19-19.5 minutes of sham stimulation
Primary Outcome Measures
NameTimeMethod
EEG Attention Lapse Measures on the Change Detection TaskThrough study completion, an average of 1 month

Pre-trial power in the alpha frequency band (8-12 Hz)

EEG Attention Lapse Measures on the Stroop Task EEG Attention Lapse Measures on the Stroop TaskThrough study completion, an average of 1 month

Pre-trial power in the alpha frequency band (8-12 Hz)

Behavioral Attention Lapse Measures on the Change Detection TaskThrough study completion, an average of 1 month

Attention factor (a); Guess factor (g)

Behavioral Cognitive Control Measures on the Stroop TaskThrough study completion, an average of 1 month

Incongruent versus Congruent difference in error rate and reaction time

EEG Cognitive Control Measures on the Stroop TaskThrough study completion, an average of 1 month

response-locked power in the theta frequency band (4-7 Hz)

Behavioral Attention Lapse Measures on the Stroop TaskThrough study completion, an average of 1 month

Error Rate on Incorrect Congruent trials (Full Lapses) and Slow-but-Correct Congruent trials (Partial Lapses)

EEG Cognitive Control Measures on the Change Detection TaskThrough study completion, an average of 1 month

delay period power in the theta frequency band (4-7 Hz)

Delivered tDCS Dose to PFCThrough study completion, an average of 1 month

Estimated electric field in PFC region of interest

Behavioral Cognitive Control Measures on the Change Detection Task Behavioral Cognitive Control Measures on the Change Detection TaskThrough study completion, an average of 1 month

WM storage capacity (k-max)

Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (1)

Imaging Research Center

🇺🇸

Sacramento, California, United States

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