Somatotopy and temporal dynamics of sensorimotor interactions: evidence from double afferent inhibition

Tamè, Luigi, Pavani, Francesco, Braun, Christoph, Salemme, Romeo, Farnè, Alessandro, Reilly, Karen T. (2015) Somatotopy and temporal dynamics of sensorimotor interactions: evidence from double afferent inhibition. European Journal of Neuroscience, 41 (11). pp. 1459-1465. ISSN 0953-816X. (doi:10.1111/ejn.12890)

Abstract

Moving and interacting with the world requires that the sensory and motor systems share information, but while some information about tactile events is preserved during sensorimotor transfer the spatial specificity of this information is unknown. Afferent inhibition studies, in which corticospinal excitability is inhibited when a single tactile stimulus is presented before a transcranial magnetic stimulation pulse over the motor cortex, offer contradictory results regarding the sensory-to-motor transfer of spatial information. Here, we combined the techniques of afferent inhibition and tactile repetition suppression (RS: the decreased neurophysiological response following double stimulation of the same vs. different fingers) to investigate whether topographic information is preserved in the sensory-to-motor transfer in humans. We developed a double afferent inhibition paradigm to examine both spatial (same vs. different finger) and temporal (short vs. long delay) aspects of sensorimotor interactions. Two consecutive electrocutaneous stimuli (separated by either 30 or 125 ms) were delivered to either the same or different fingers on the left hand (i.e., index finger stimulated twice or middle finger stimulated before index finger). Information about which fingers were stimulated was reflected in the size of the motor responses in a time-constrained manner: corticospinal excitability was modulated differently by same and different finger stimulation only when the two stimuli were separated by the short delay (p=.004). We demonstrate that the well-known response of the somatosensory cortices following repetitive stimulation is mirrored in the motor cortex and that corticospinal excitability is modulated as a function of the temporal and spatial relationship between afferent stimuli.

Item Type:	Article
DOI/Identification number:	10.1111/ejn.12890
Uncontrolled keywords:	SENSORIMOTOR INTERACTIONS BETWEEN FINGERS
Subjects:	B Philosophy. Psychology. Religion
Divisions:	Faculties > Social Sciences > School of Psychology Faculties > Social Sciences > School of Psychology > Cognitive Psychology
Depositing User:	Luigi Tame
Date Deposited:	23 Jan 2019 15:46 UTC
Last Modified:	30 May 2019 08:43 UTC
Resource URI:	https://kar.kent.ac.uk/id/eprint/71603 (The current URI for this page, for reference purposes)
Tamè, Luigi:	https://orcid.org/0000-0002-9172-2281