Multiple sensorimotor loops converge in the motor cortex to create an adaptable system capable of context-specific sensorimotor control.
Afferent inhibition provides a non-invasive tool to investigate the substrates by which procedural and cognitive control processes interact to shape motor corticospinal projections. Varying the transcranial magnetic stimulation properties during afferent inhibition can probe specific sensorimotor circuits that contribute to short- and long-latency periods of inhibition in response to the peripheral stimulation.
The current study used short- SAI and long-latency LAI afferent inhibition to probe the influence of verbal and spatial working memory load on the specific sensorimotor circuits recruited by posterior-anterior PA and anterior-posterior AP TMS-induced current. Participants completed two sessions where SAI and LAI were assessed during the short-term maintenance of two- or six-item sets of letters verbal or stimulus locations spatial.
The only difference between the sessions was the direction of the induced current. PA SAI decreased as the verbal working memory load increased. The dissociation of short-latency PA and AP sensorimotor circuits and short- and long-latency PA sensorimotor circuits with increasing verbal working memory load support multiple convergent sensorimotor loops that provide distinct functional information to facilitate context-specific supraspinal control.
Citation: Lenizky MW, Meehan SK The effects of verbal and spatial working memory on short- and long-latency sensorimotor circuits in the motor cortex. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
