Perceptually relevant remapping of human somatotopy in 24 hours.

James Kolasinski,Saad Jbabdi,John P Logan,Tamar R Makin,Stuart Clare,Heidi Johansen-Berg,Charlotte J Stagg

doi:10.7554/elife.17280

James Kolasinski, Saad Jbabdi + Show 5 more

Open Access

https://doi.org/10.7554/elife.17280

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Abstract

Experience-dependent reorganisation of functional maps in the cerebral cortex is well described in the primary sensory cortices. However, there is relatively little evidence for such cortical reorganisation over the short-term. Using human somatosensory cortex as a model, we investigated the effects of a 24 hr gluing manipulation in which the right index and right middle fingers (digits 2 and 3) were adjoined with surgical glue. Somatotopic representations, assessed with two 7 tesla fMRI protocols, revealed rapid off-target reorganisation in the non-manipulated fingers following gluing, with the representation of the ring finger (digit 4) shifted towards the little finger (digit 5) and away from the middle finger (digit 3). These shifts were also evident in two behavioural tasks conducted in an independent cohort, showing reduced sensitivity for discriminating the temporal order of stimuli to the ring and little fingers, and increased substitution errors across this pair on a speeded reaction time task.

Highlights

Evidence for experience-dependent plasticity in the adult mammalian brain exists across a variety of sensory modalities (Fu and Zuo, 2011)
Considerable emphasis has been placed upon cross-sectional differences in the cortical organisation of SI observed in specialist populations, such as musicians, or patients with sensorimotor dysfunction, such as focal dystonia (Elbert et al, 1995; Bara-Jimenez et al, 1998; Nelson et al, 2009; Kalisch et al, 2009)
We first asked whether the amount of cortical overlap between digit representations in SI changed after the gluing manipulation in comparison with two control sessions using the phase-encoding fMRI data

Summary

Introduction

Evidence for experience-dependent plasticity in the adult mammalian brain exists across a variety of sensory modalities (Fu and Zuo, 2011). An alternative hypothesis posited that compensatory behaviour during the 24 hr gluing manipulation would promote changes in the cortical representations of adjacent, but unaffected digits. We first asked whether the amount of cortical overlap between digit representations in SI changed after the gluing manipulation in comparison with two control sessions using the phase-encoding fMRI data.

Results

Conclusion