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The effect of dual-task difficulty on the inhibition of the motor cortex

Version 2 2024-06-06, 02:09
Version 1 2015-11-12, 16:52
journal contribution
posted on 2024-06-06, 02:09 authored by Daniel CorpDaniel Corp, Mark RogersMark Rogers, George YoussefGeorge Youssef, AJ Pearce
Dual-tasking is intrinsic to many daily activities, including walking and driving. However, the activity of the primary motor cortex (M1) in response to dual-tasks (DT) is still not well characterised. A recent meta-analysis (Corp in Neurosci Biobehav Rev 43:74-87, 2014) demonstrated a reduction in M1 inhibition during dual-tasking, yet responses were not consistent between studies. It was suggested that DT difficulty might account for some of this between-study variability. The aim of this study was to investigate whether corticospinal excitability and M1 inhibition differed between an easier and more difficult dual-task. Transcranial magnetic stimulation (TMS) was applied to participants' abductor pollicis brevis muscle representation during a concurrent pincer grip task and stationary bike-riding. The margin of error in which to maintain pincer grip force was reduced to increase task difficulty. Compared to ST conditions, significantly increased M1 inhibition was demonstrated for the easier, but not more difficult, DT. However, there was no significant difference in M1 inhibition between easy and difficult DTs. The difference in difficulty between the two tasks may not have been wide enough to result in significant differences in M1 inhibition. Increased M1 inhibition for the easy DT condition was in opposition to the reduction in M1 inhibition found in our meta-analysis (Corp in Neurosci Biobehav Rev 43:74-87, 2014). We propose that this may be partially explained by differences in the timing of the TMS pulse between DT studies.

History

Journal

Experimental Brain Research

Volume

234

Pagination

443-452

Location

Germany

ISSN

0014-4819

eISSN

1432-1106

Language

English

Publication classification

C Journal article, C1 Refereed article in a scholarly journal

Copyright notice

2016, Springer International Publishing

Issue

2

Publisher

SPRINGER