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

Najat Khalifa

Status: Completed

Conditions: Impulsive Behavior

Treatments: Device: Sham tDCS; Device: Anodal tDCS

Study type: Interventional

Funder types: Other

Identifiers

NCT03484377

199-1801 (Other Identifier)

CiC2017051

Details and patient eligibility

About

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.

Full 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.

Enrollment: 36 patients

Sex: All

Ages: 18 to 40 years old

Volunteers: Accepts Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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36 participants in 2 patient groups

Anodal tDCS

Experimental group

Description:

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.

Treatment:

Device: Anodal tDCS

Sham tDCS

Sham Comparator group

Description:

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.

Treatment:

Device: Sham tDCS