Practice makes perfect: the neural substrates of tactile discrimination by Mah-Jong experts include the primary visual cortex.
BACKGROUND
It has yet to be determined whether visual-tactile cross-modal plasticity due to visual deprivation, particularly in the primary visual cortex (V1), is solely due to visual deprivation or if it is a result of long-term tactile training. Here we conducted an fMRI study with normally-sighted participants who had undergone long-term training on the tactile shape discrimination of the two dimensional (2D) shapes on Mah-Jong tiles (Mah-Jong experts). Eight Mah-Jong experts and twelve healthy volunteers who were naïve to Mah-Jong performed a tactile shape matching task using Mah-Jong tiles with no visual input. Furthermore, seven out of eight experts performed a tactile shape matching task with unfamiliar 2D Braille characters.


RESULTS
When participants performed tactile discrimination of Mah-Jong tiles, the left lateral occipital cortex (LO) and V1 were activated in the well-trained subjects. In the naïve subjects, the LO was activated but V1 was not activated. Both the LO and V1 of the well-trained subjects were activated during Braille tactile discrimination tasks.


CONCLUSIONS
The activation of V1 in subjects trained in tactile discrimination may represent altered cross-modal responses as a result of long-term training.
Saito
Daisuke N
DN
Division of Cerebral Integration, National Institute for Physiological Sciences, Okazaki, Japan. sdaisuke@nips.ac.jp <sdaisuke@nips.ac.jp>
Okada
Tomohisa
T
Honda
Manabu
M
Yonekura
Yoshiharu
Y
Sadato
Norihiro
N
D000328:Adult; D004193:Discrimination Learning / Q000502:physiology*; D004569:Electroencephalography; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005074:Evoked Potentials, Visual / Q000502:physiology*; D006801:Humans; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D010812:Physical Stimulation / Q000379:methods; D010988:Play and Playthings; D013647:Task Performance and Analysis; D014110:Touch / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*