Handedness, footedness, and language laterality: evidence from Wada testing

A total of 37 candidates for temporal lobe resection for epilepsy completed the Lateral Dominance Examination, a self-report instrument that measures hand and foot preference. Questionnaire results were compared with speech dominance, which had been determined by Intracarotid Sodium Amytal Procedure. Footedness was as good as handedness as a predictor of language laterality.

Qualitative differences in tactuo-spatial motor learning by left-handers

Tactuo-spatial performance was studied as a function of subject handedness and hand employed in learning and transfer. Seventy-eight dextral and 75 sinistral blindfolded subjects learned a finger-maze with either dominant or nondominant hand. Transfer to the untrained hand was assessed with either an identical or a mirror-image version of the maze. Left hand acquisition required fewer trials; latencies were shorter when the dominant hand was used. All dextrals and those sinistral subjects who used the right hand in acquisition showed superior transfer to the identical maze. Sinistral subjects who used the left hand in acquisition demonstrated facilitated transfer to the mirror image maze. Results are suggested to provide evidence of two qualitatively different hemispheric strategies for encoding tactuo-spatial information.