The role of interhemispheric inhibition mechanisms during partial response inhibition of prepared motor actions.

Day, Alice Catherine (2020). The role of interhemispheric inhibition mechanisms during partial response inhibition of prepared motor actions. University of Birmingham. M.Sc.

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Abstract

One aspect of impulse control in human motor behaviour is the cancellation of part of an action without warning, while the remaining parts continue. Previous research has highlighted a distinct pattern of corticomotor excitability modulation, whereby excitability increases with the anticipation of movement, then is inhibited when required actions are suddenly altered, and finally reinitiated with the required response. The present study aimed to investigate interhemispheric inhibitory mechanisms between the two primary motor cortices as a possible method of partial response inhibition modulation. Transcranial magnetic stimulation was given to participants while they performed an anticipatory response inhibition task in the form of a bimanual index finger abduction task, intercepting a target line with two rising bars on a screen. Occasionally, participants were required to inhibit the finger abduction response of either one or both index fingers. When inhibiting the left-hand response and continuing the right, there was a dissociation in interhemispheric inhibition post stop cue, with interhemispheric inhibition being released onto the responding hand and increased for the cancelled hand. This dissociation suggests interhemispheric inhibition allows for the uncoupling of motor actions before the subsequent reinitiation of required responses. Interhemispheric inhibition is therefore fundamental to partially inhibiting movement responses.

Type of Work:

Thesis (Masters by Research > M.Sc.)

Award Type:

Masters by Research > M.Sc.

Supervisor(s):