None listed
Conditions
Brief summary
Motor imagery (MI) refers to the mental simulation of movement in the absence of overt movement. A strong body of evidence suggests that MI activates the human motor system in similar ways to actual movement. For example, the time taken to mentally simulate movement correlates with actual movement time, while there is considerable overlap in the neural systems activated during real and imagined movement. Interestingly, MI based interventions have shown moderate effect at improving motor ability in healthy adults (e.g. athletes) and patient groups (e.g. stroke). In some cases MI appears to be an effective adjunct to actual movement therapies for improving action efficiency. However, evidence as to the efficacy of MI therapies nonetheless remains mixed. Research, in large part, has attributed this to a poor understanding of the neural basis of MI. To this end, the putative role of important ‘motor’ structures such as the primary motor cortex (PMC) and the Supplementary motor cortices (SMA) remain debated. Clarifying the role of the PMC and SMA in MI is critical to developing a unified account of motor control, and the development of effective interventions for those with motor difficulties. Aim: The proposed study will aim to clarify the role of the PMC and SMA in MI in samples of young adults (18 to 35 years) with and without movement problems.
Interventions
Eligible participants will be invited to attend 3 x 1 hour assessment sessions which will each be separated by at least one week.
At the commencement of each session, participants will be given a safety questionnaire to assess their eligibility for Transcranial magnetic stimulation (TMS). Those who meet project eligibility will then proceed with the session. During each session, they will first undergo single-pulse TMS to determine their resting motor threshold, administered by a member of the
Eligible participants will be invited to attend 3 x 1 hour assessment sessions which will each be separated by at least one week. At the commencement of each session, participants will be given a safety questionnaire to assess their eligibility for Transcranial magnetic stimulation (TMS). Those who meet project eligibility will then proceed with the session. During each session, they will first undergo single-pulse TMS to determine their resting motor threshold, administered by a member of the research team (which includes postgraduate research students). They will then be administered one of the following three continuous theta burst stimulation (cTBS) procedures: active cTBS to either the left primary motor cortex (PMC) or left supplementary motor area (SMA), or sham cTBS to the PMC or SMA. With respect to the latter sham cTBS session, half of participants will have the PMC stimulated during the 'sham' session, and the other half the SMA- this process will be randomized. During 'active' sessions, cTBS will be delivered at 70% of an individual’s “motor threshold” and involve delivery of 3 pulses within .06 seconds, repeated every .2 seconds (5 times per second) for 40 seconds. Following administration of the respective cTBS protocol, participants will then complete two computer tasks: one requiring them to determine the laterality of hand stimuli; and the second requiring them to determine whether alphanumeric stimuli presented are the correct or incorrect orientation. Finally, at the end of each session, single-pulse TMS will be re-administered to determine whether resting motor threshold has altered during the session.
Sponsors
Deakin University
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Diagnosis
Masking
Blinded (masking used) (Subject, Caregiver)
Eligibility
Sex/Gender
All
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
Young adults will have age-appropriate motor skill and will not present with a prior diagnosis of a motor related medical disorder, neurodevelopmental disorder or intellectual impairment. OR Adults with motor skill significantly below that expected of their age. This atypical motor skill will not be otherwise explained by a relevant diagnosed medical condition, neuro developmental disorder or intellectual disability.
Exclusion criteria
Anyone who demonstrates a contra-indication for TMS. This includes (but is not limited to): • History of seizure • Previous clinical EEG where presence of seizure activity has not been excluded • Professional driver or machine operator • Previous brain surgery or brain injury • Ferromagnetic metal in the head outside of the mouth • Implanted medical device • Serious or unstable illness or medical condition • Current or suspected pregnancy or current lactation • Any illicit drug use within past 7 days • Any alcohol use in past 12 hours, or more than 3 standard drinks in past 24 hours Recent insomnia or another form of sleep deprivation Further, children will not be asked to participate in this project since their inclusion is not required (or necessary) for the study aims to be achieved. People with intellectual or mental impairment and those highly dependent on medical care will be excluded since some health conditions are contraindicators of the TMS procedure that we propose to adopt in this project. These are appropriately (as per Deakin University procedures) screened for as part of the proposed screening protocol described later. People whose primary language is not English will be disadvantaged on some of the assessment tasks which were developed, and where appropriately normed, for English speaking individuals. Accordingly, these assessments are unlikely to provide a true representation of a non-English speaking individuals' abilities and hence they will be excluded from participation. In the case of the exclusion of pregnant women, pregnancy is a contraindication of the TMS procedures that we propose to adopt in this project.
Outcome results
None listed