Research article

Practice makes perfect: the neural substrates of tactile discrimination by Mah-Jong experts include the primary visual cortex

Daisuke N Saito^1,2 , Tomohisa Okada¹ , Manabu Honda³ , Yoshiharu Yonekura⁴ and Norihiro Sadato^1,2,5

¹  Division of Cerebral Integration, National Institute for Physiological Sciences, Okazaki, Japan

²  JST (Japan Science and Technology Corporation)/RISTEX (Research Institute of Science and Technology for Society), Kawaguchi, Japan

³  Department of Cortical Function Disorders, National Institute of Neuroscience, National Center for Neurology and Psychiatry, Tokyo, Japan

⁴  Biomedical Imaging Research Center, University of Fukui, Fukui, Japan

⁵  Department of Functional Neuroimaging, Faculty of Medical Sciences, University of Fukui, Fukui, Japan

author email corresponding author email

BMC Neuroscience 2006, 7:79doi:10.1186/1471-2202-7-79

Published:	5 December 2006

Abstract

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.

Conclusion

The activation of V1 in subjects trained in tactile discrimination may represent altered cross-modal responses as a result of long-term training.