Right- and left-handed counting of braille dots in subjects unaccustomed to braille.

Previous work has shown that children acquainted with Braille can usually read better with their left than with their right hand. It is also known that, at least in right-handed people, the right cerebral hemisphere is dominant for counting dots. The present paper compares, in right-handed subjects unacquainted with Braille, the comparative skill of right and left middle (M) and index (I) fingers in counting Braille dots. In one experiment with 30 subjects no significant difference was found between LI and RI fingers. Another experiment failed to reveal any R/L differences although it detected a superiority of I over M fingers at P less than 0-025. When the task was split between the two I fingers working simultaneously they performed significantly (P less than 0-001) better than when working alone. This latter finding is thought to have a bearing on the failure to detect R/L differences; other possible explanations of the findings are also discussed.