Asymmetrical transfer of braille acquisition between hands.

Two experiments are presented which demonstrate asymmetrical transfer for tactual recognition of individual braille letters in sighted subjects, a task usually associated with right hemisphere specialization. Right-handers were studied in Experiment 1, left- and right-handers in Experiment 2. Poor transfer of training from the right hand to the left hand was observed for right-handed subjects in both experiments. The same was true for one group of left-handers (who wrote with the "inverted" position). For another group (who wrote with the "noninverted" position), no disadvantage was associated with opposite-hand training for either hand. The role of hemispheric specialization of function in determining the direction of greater transfer is discussed, and it is argued that handwriting posture may be an index of the degree of functional "connectedness" of the two hemispheres in left-handers.