Title
Writing's shadow: corticospinal activation during letter observation.
Abstract
We can recognize handwritten letters despite the variability among writers. One possible strategy is exploiting the motor memory of orthography. By using TMS, we clarified the excitatory and inhibitory neural circuits of the motor corticospinal pathway that might be activated during the observation of handwritten letters. During experiments, participants looked at the handwritten or printed single letter that appeared in a random order. The excitability of the left and right primary motor cortex (M1) was evaluated by motor-evoked potentials elicited by single-pulse TMS. Short interval intracortical inhibition (SICI) of the left M1 was evaluated using paired-pulse TMS. F waves were measured for the right ulnar nerve. We found significant reduction of corticospinal excitability only for the right hand at 300-400 msec after each letter presentation without significant changes in SICI. This suppression is likely to be of supraspinal origin, because of no significant alteration in F-wave amplitudes. These findings suggest that the recognition of handwritten letters may include the implicit knowledge of "writing" in M1. The M1 activation associated with that process, which has been shown in previous neuroimaging studies, is likely to reflect the active suppression of the corticospinal excitability.
Year
DOI
Venue
2012
10.1162/jocn_a_00205
J. Cognitive Neuroscience
Keywords
Field
DocType
right hand,primary motor cortex,left m1,corticospinal activation,motor memory,letter observation,handwritten letter,right ulnar nerve,paired-pulse tms,motor corticospinal pathway,corticospinal excitability,m1 activation,dam
Neuroscience,Muscle memory,Implicit knowledge,Psychology,Excitatory postsynaptic potential,Inhibitory postsynaptic potential,Orthography,Neuroimaging,Biological neural network,Primary motor cortex
Journal
Volume
Issue
ISSN
24
5
1530-8898
Citations 
PageRank 
References 
1
0.39
8
Authors
6
Name
Order
Citations
PageRank
Masahiro Nakatsuka111.40
Mohamed Nasreldin Thabit210.39
Satoko Koganemaru310.39
Ippei Nojima451.16
Hidenao Fukuyama511419.80
T Mima6186.26