Functional specificity in the motor system: Evidence from coupled fMRI and kinematic recordings during letter and digit writing

Marieke Longcamp, Aurélie Lagarrigue, Bruno Nazarian, Muriel Roth, Jean-Luc Anton, Francois-Xavier Alario, Jean-Luc Velay
2014 Human Brain Mapping  
A few intriguing neuropsychologial studies report dissociations where agraphic patients are severely impaired for writing letters whereas they write digits nearly normally. Here, using functional magnetic resonance imaging (fMRI) together with graphic tablet recordings, we tested the hypothesis that the motor patterns for writing letters are coded in specific regions of the cortex. We found a set of three regions that were more strongly activated when participants wrote letters than when they
more » ... ote digits and whose response was not explained by low-level kinematic features of the graphic movements. Two of these regions (left dorsal premotor cortex and supplementary motor complex) are part of a motor control network. The left premotor activation belongs to what is considered in the literature a key area for handwriting. Another significant activation, likely related to phoneme-tographeme conversion, was found in the right anterior insula. This constitutes the first neuroimaging evidence of functional specificity derived from experience in the cortical motor system. Hum Brain Mapp 00:000-000, 2014. V C 2014 Wiley Periodicals, Inc.
doi:10.1002/hbm.22606 pmid:25093278 fatcat:hawsdhld4nfyxmiv7x73f5bnv4