ANZCTR - Registration

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Trial registered on ANZCTR

Registration number

ACTRN12622000871741

Ethics application status

Approved

Date submitted

14/06/2022

Date registered

20/06/2022

Date last updated

20/06/2022

Date data sharing statement initially provided

20/06/2022

Type of registration

Retrospectively registered

Titles & IDs

Public title

Degree of habitual behaviour modulation of non-invasive brain stimulation effects on cognitive flexibility in healthy participants.

Scientific title

Degree of habitual behaviour modulation of non-invasive brain stimulation effects on cognitive flexibility in healthy participants.

Secondary ID [1]

Nil known

Universal Trial Number (UTN)

Trial acronym

Linked study record

Health condition

Health condition(s) or problem(s) studied:

Learning

Condition category

Condition code

Mental Health

Studies of normal psychology, cognitive function and behaviour

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

In this study, all participants will first complete a self-report report measure of habitual behaviour called Creatures of Habit Scale.

Second, they will then complete a well-established neuropsychological measure of cognitive flexbility known as the Wisconsin Card Sorting Test. The test will be administered in the lab using a piece of software called PEBL.

Third, they will undergo either cathodal transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (dlPFC) or sham (control). The order of tDCS allocation will be randomized for each participant. To avoid potential carryover effects of tDCS, as this is a crossover design, each session will be separated by at least 72 hours.

A current at 1.5 mA will be delivered for 10 minutes while the participant is relaxed plus the additional duration of the Wisconsin Card Sorting test (approximately 7 minutes) with additional 30-second fade-in/fade-out periods. A current of 1.5 mA has been selected because 2.0 mA can compromise tDCS blinding in repeated measures/crossover designs.

Testing will be carried out by an honours research student supervised by the PI and carried out in the Mind & Body lab at Murdoch University.

Intervention code [1]

Treatment: Devices

Intervention code [2]

Behaviour

Comparator / control treatment

For sham (control) stimulation, a current of 1.5 mA will be faded in over 30 seconds and then switched off. Double blinding will be achieved using the neuroConn study mode software and a different experimenter inputted a pre-assigned numerical code into the tDCS device to select the experimental condition (sham vs.cathodal).

Control group

Placebo

Outcomes

Primary outcome [1]

Total errors in the Wisconsin Card Sorting task

Timepoint [1]

Immediately before tDCS (sham or cathodal) and 10 minutes following tDCS activation across two experimental sessions.

Primary outcome [2]

Perseverative errors in Wisconsin Card Sorting Test

Timepoint [2]

Immediately before tDCS (sham or cathodal) and 10 minutes following tDCS activation across two experimental sessions.

Primary outcome [3]

Reaction times in the Wisconsin Card Sorting task

Timepoint [3]

Immediately before tDCS (sham or cathodal) and 10 minutes following tDCS activation across two experimental sessions.

Secondary outcome [1]

Failure to maintain set in the Wisconsin Card Sorting task

Timepoint [1]

Immediately before tDCS (sham or cathodal) and 10 minutes following tDCS activation across two experimental sessions.

Eligibility

Key inclusion criteria

• You are aged between 18 and 50 years (the upper age limit of 50 years has been selected as there is some evidence that mild cognitive decline begins past this age)
• You are in good health
• You agree to fast 3 hours prior to testing (only water or herbal tea allowed) (glucose levels are known to modulate performance in several cognitive domains. By having all participants fast for 3 hours prior to testing, we can rule out an enhancing effect of glucose on the cognitive flexibility task).

Minimum age

18 Years

Maximum age

50 Years

Sex

Both males and females

Can healthy volunteers participate?

Yes

Key exclusion criteria

Participants will not be able to participate if they:
• Suffer from cardiac, hepatic, renal, and/or neurological disorders
• Have damaged or diseased skin on your face and scalp, or a sensitive scalp
• Have a history of alcohol or drug addiction, or severe psychiatric illness
• Are receiving drug treatment which may lower seizure threshold (i.e. epilepsy)
• Are pregnant
• Are sleep deprived (less than 6 hours a day)
• Have metallic dental fillings, orthodontic appliances, a cardiac pacemaker, cochlear
implant, and/or surgical clips

Study design

Purpose of the study

Treatment

Allocation to intervention

Randomised controlled trial

Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)

I, as the researcher randomising the participant do not know what the next treatment allocation will be as testing is carried out by my students.

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

Simple randomisation using a randomisation table created by computer software (i.e. computerised sequence generation)

Masking / blinding

Blinded (masking used)

Who is / are masked / blinded?

The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes

Intervention assignment

Crossover

Other design features

Phase

Not Applicable

Type of endpoint/s

Efficacy

Statistical methods / analysis

Recruitment

Recruitment status

Recruiting

Date of first participant enrolment

Anticipated

Actual

14/06/2022

Date of last participant enrolment

Anticipated

16/09/2022

Actual

Date of last data collection

Anticipated

16/09/2022

Actual

Sample size

Target

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

Funding & Sponsors

Funding source category [1]

University

Name [1]

Murdoch University

Address [1]

90 South Street, Murdoch, 6150, WA.

Country [1]

Australia

Primary sponsor type

University

Name

Murdoch University

Address

90 South Street, Murdoch, 6150, WA.

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Address [1]

Country [1]

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

Murdoch University Human Research Ethics Committee

Ethics committee address [1]

90 South Street, Murdoch, 6150, WA

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

Approval date [1]

09/06/2022

Ethics approval number [1]

Summary

Brief summary

We are trying to establish whether the degree to which one self-reports to be low or high in habitual behaviour can in turn affect the efficacy of non-invasive brain stimulation on measures of cognitive flexibility. Our hypothesis is that performance on cognitive flexibility will be worst for those high in habitual behaviour when receiving inhibitory non-invasive brain stimulation but not during control/sham stimulation.

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

Dr Luca Aquili

Address

Murdoch University
90 South Street,
Murdoch, 6150,
WA

Country

Australia

Phone

+61 89360 2348

Fax

[email protected]

Contact person for public queries

Name

Luca Aquili

Address

Murdoch University
90 South Street,
Murdoch, 6150,
WA

Country

Australia

Phone

+61 89360 2348

Fax

[email protected]

Contact person for scientific queries

Name

Luca Aquili

Address

Murdoch University
90 South Street,
Murdoch, 6150,
WA

Country

Australia

Phone

+61 89360 2348

Fax

[email protected]

Data sharing statement

Will individual participant data (IPD) for this trial be available (including data dictionaries)?

No/undecided IPD sharing reason/comment

What supporting documents are/will be available?

Doc. No.	Type	Citation	Link	Email	Other Details	Attachment
16370	Ethical approval					384215-(Uploaded-14-06-2022-16-54-57)-Study-related document.pdf

Results publications and other study-related documents

Documents added manually

Type	Is Peer Reviewed?	DOI	Citations or Other Details	Attachment
Study results article	Yes		Yatan, G., Lim, L. W., & Aquili, L. (2023). Routin... [More Details]	384215-(Uploaded-27-03-2023-18-47-51)-Journal results publication.pdf

Documents added automatically

Source	Title	Year of Publication	DOI
Embase	Routine behaviour, a putative dopamine marker, predicts cognitive flexibility by tDCS of the dlPFC.	2023	https://dx.doi.org/10.1016/j.brs.2023.01.1676

N.B. These documents automatically identified may not have been verified by the study sponsor.

Trial Review

Documents added manually

Documents added automatically