HD-tDCS Over the dACC in High Trait Impulsivity

Not Applicable

Completed

• Conditions: Impulsive Behavior
• Interventions: Device: Sham High Definition transcranial Direct Current Stimulation (HD-tDCS); Device: Active High Definition transcranial Direct Current Stimulation (HD-tDCS)

• Registration Number: NCT04290533
• Lead Sponsor: Monash University

Brief Summary

Psychological disorders characterized by impulsivity often show alterations in dorsal anterior cingulate cortex (dACC) activity. Recent research has therefore focused on non-invasive neurostimulation therapies for the modulation of functional activity in the dACC. To date there has only been one proof-of-concept study providing evidence for modulating dACC activity with non-invasive electrical neurostimulation (e.g. transcranial electrical stimulation). Since transcranial Direct Current Stimulation (tDCS) is relatively safe, tolerable, and mobile as compared to other neurostimulation techniques, it is worthwhile looking further into the effects of tDCS on functional dACC activity. The aim of the present research is to explore whether HD-tDCS can induce changes in the dACC in individuals with high trait impulsivity (N=20) in a double-blind cross-over study. Functional changes in dACC activity will be measured by the error related negativity (ERN), which is an event related potential generated by the dACC. The ERN is less pronounced in people that score high on impulsivity. It is therefore expect enhanced ERN amplitudes after HD-tDCS over the dACC. In addition, performance on the multisource interference task will be used as measure of dACC activity. It is hypothesize that increased dACC activity will be related to decreased impulsivity in high impulsive individuals as shown by improved inhibitory control on the Go/NoGo task. The results of the study may have implications for patient populations that are characterized by impulsivity.

Detailed Description

Not available

Study Timeline

• Study Start: 2019-03-04
• Primary Completion: 2019-12-15
• Study Completion: 2020-01-15
• Study First Submitted: 2020-02-18
• Study First Submitted QC: 2020-02-26
• Study First Posted: 2020-03-02
• Status Verified: 2021-05
• Last Update Submitted: 2021-05-13
• Last Update Posted: 2021-05-17

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 23

Inclusion Criteria

• Right-handed
• Score > 46 on SUPPS-P

Exclusion Criteria

• Score low on trait impulsivity as determined by a score of < 47 on the SUPPS-P short form
• History of DSM-5 defined neurological illness, mental illness or traumatic brain injury,
• Currently taking any psychoactive medications,
• Have metal anywhere in the head, except the mouth. This includes metallic objects such as screws, plates and clips from surgical procedures.
• Currently pregnant or lactating,
• Being left-handed

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Sham HD-tDCS	Sham High Definition transcranial Direct Current Stimulation (HD-tDCS)	-
Active HD-tDCS	Active High Definition transcranial Direct Current Stimulation (HD-tDCS)	-

Primary Outcome Measures

Name	Time	Method
Change in error related negativity (ERN) measured by electroencephalography (EEG) after active and sham HD-tDCS	Baseline, directly after (active vs. sham) HD-tDCS, and 30 min after (active vs. sham) HD-tDCS.	To measure changes in electrophysiological measures of error processing after active vs. sham HD-tDCS
Change in NoGo P3 measured by electroencephalography (EEG) after active and sham HD-tDCS	Baseline, directly after (active vs. sham) HD-tDCS, and 30 min after (active vs. sham) HD-tDCS.	To measure changes in electrophysiological measures of motor inhibitory control processes after active vs. sham HD-tDCS
Change in NoGo N2 measured by electroencephalography (EEG)	Baseline, directly after (active vs. sham) HD-tDCS, and 30 min after (active vs. sham) HD-tDCS.	To measure changes in electrophysiological measures of early inhibitory control processes after active vs. sham HD-tDCS

Secondary Outcome Measures

Name	Time	Method
Change in reaction times post incorrect trials during Go/NoGo task after active vs. sham HD-tDCS	Baseline, directly after (active vs. sham) HD-tDCS, and 30 min after (active vs. sham) HD-tDCS.	To measure the effect of active vs. sham HD-tDCS on post-error slowing as behavioural measure of error processing.
Change in percentage of correct nogo trials on Go/NoGo task after active vs. sham HD-tDCS	Baseline, directly after (active vs. sham) HD-tDCS, and 30 min after (active vs. sham) HD-tDCS.	To measure the effect of active vs. sham HD-tDCS on accuracy on trials for which responses have to be inhibited. Represents a measure of change in inhibitory control.
Change in reaction times on Go trials during Go/NoGo task after active vs. sham HD-tDCS	Baseline, directly after (active vs. sham) HD-tDCS, and 30 min after (active vs. sham) HD-tDCS.	To measure changes in speed of motor responses during Go/NoGo task differences after active vs. sham HD-tDCS
Change in interference effect on multisource interference task (MSIT) after active vs. sham HD-tDCS	Baseline, directly after (active vs. sham) HD-tDCS, and 30 min after (active vs. sham) HD-tDCS.	The interference effect is calculated by subtracting the mean reaction time for congruent trials from the mean reaction time for incongruent trials. A larger interference effect reflects worse performance and is suggested to reflect decreased dACC activity.

Trial Locations

Locations (1)

Monash University, BrainPark; 🇦🇺 Melbourne, Victoria, Australia