Cortical Dynamics of Inhibitory Control: A Concurrent tDCS-MEG Study (CDIC-tDCS)

Measuring Cortical Dynamics of Inhibitory Control Before, During and After Transcranial Direct Current Stimulation (tDCS)

This study aims to use concurrent Transcranial Direct Current Stimulation (tDCS) and Magnetoencephalography (MEG) with measures of impulsivity to examine the neurobiological underpinnings of rapid response impulsivity (RRI) and how these can be modified using tDCS in healthy subjects.

Study Overview

• Status: Completed
• Conditions: Impulsive Behavior
• Intervention / Treatment: Device: Anodal tDCS; Device: Sham tDCS

Detailed Description

Concurrent tDCS-MEG parallel arms single-blinded experimental design (right anodal v sham tDCS) will be employed in this study. The study will be conducted at the University of Nottingham, using a sample of student volunteers. This study aims to examine the influence of anodal tDCS on beta-band and alpha-band oscillatory activities, using an anti-saccade task administered before, during and after tDCS stimulation. It can potentially help understand the neurobiological mechanisms underpinning rapid response impulsivity and how these can be influenced by tDCS.

The research hypotheses are that (i) a generalised mechanism for top-down inhibitory control will play a vital role, whereby prefrontal beta-band activity initiates alpha-band activity for functional inhibition over the frontal eye fields and other areas in the neurocircuitry involved in RRI; (ii) anodal tDCS (as opposed to sham) delivered over the right DLPFC will enhance this mechanism; and (iii) there will be no significant correlations between measures of self-report impulsivity and performance on the anti-saccade task and measures of oscillatory activity.

• Study Type: Interventional
• Enrollment (Actual): 36
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Notts
    • Nottingham, Notts, United Kingdom, NG7 2TU
      • University of Nottingham

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 40 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• University students and staff
• Aged 18-40

Exclusion Criteria:

• Individuals with epilepsy and other neurological conditions, history of significant head injury, substance misuse, major mental disorder and those receiving psychotropic medication.
• Contraindications to use of Magnetic Resonance (pacemakers, metal implants, aneurysm clips)
• Pregnancy.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Anodal tDCS; The anodal tDCS electrode will be placed over the area corresponding to the right DLPFC (F4 of the EEG10-20 international system). The anodal tDCS condition will use a constant current of 2mA, delivered via gradual increase and decrease over 10 seconds at the onset and offset of stimulation (current ramps), respectively.	Device: Anodal tDCS; The experimental condition will use a constant current of 2mA for 20 minutes, delivered via gradual increase and decrease over 10 seconds at the onset and offset of stimulation (current ramps), respectively.
Sham Comparator: Sham tDCS; The sham (cathodal) electrode will be placed over the left supraorbital ridge. The current will be delivered only in the first 10 seconds, after which the stimulation will cease but with the electrodes still in place throughout the session.	Device: Sham tDCS; The anodal electrode will be placed over the supreorbital ridge. The current will be delivered only in the first 10 seconds, after which the stimulation will cease but with the electrodes still in place throughout the session. The session will last for 20 minutes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total number of correct anti-saccade (AS) trials	A measure of rapid response impulsivity (inhibitory control)	Change from baseline after 20 minutes of tDCS

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total number of correct pro-saccade (PS) trials	A behavioral measure of rapid response impulsivity (inhibitory control)	Change from baseline after 20 minutes of tDCS
Saccade latency for anti-saccade (AS) trials	A behavioral measure of rapid response impulsivity (inhibitory control)	Change from baseline after 20 minutes of tDCS
Saccade latency for pro-saccade (PS) trials	A behavioral measure of rapid response impulsivity (inhibitory control)	Change from baseline after 20 minutes of tDCS
Total Scores on the UPPS+P Impulsive Behaviour Scale	A self-report measure of impulsivity	Baseline
Alpha and Beta band activity	A Cortical measure of inhibitory control recorded using Magnetoencephalography (MEG). MEG is a brain imaging technique.	Change from baseline after 20 minutes of tDCS

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Alpha and Beta band activity	Evaluation of mechanism of action of tDCS using MEG data	During 20 minutes of tDCS stimulation

Collaborators and Investigators

• Sponsor: Najat Khalifa
• Collaborators: University of Nottingham; Medical Research Council
• Investigators: Principal Investigator: Najat Khalifa, DM, University of Nottingham

Study record dates

Study Major Dates

• Study Start (Actual): September 15, 2018
• Primary Completion (Actual): February 14, 2019
• Study Completion (Actual): February 28, 2019

Study Registration Dates

• First Submitted: March 14, 2018
• First Submitted That Met QC Criteria: March 23, 2018
• First Posted (Actual): March 30, 2018

Study Record Updates

• Last Update Posted (Actual): February 25, 2020
• Last Update Submitted That Met QC Criteria: February 24, 2020
• Last Verified: February 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Impulsive Behavior
• Other Study ID Numbers: CiC2017051; 199-1801 (Other Identifier: Research Ethics - University of Nottingham)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

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