Evidence for the pathological right-handedness hypothesis.
The present study investigated handedness of 109 Korean patients with temporal lobe epilepsy (TLE) and 120 normal control participants. Left TLE was associated with a significantly raised incidence of left-handers relative to normal controls. More important for the present purpose, right TLE was associated with a significantly raised incidence of strong right-handers relative to normal controls. This finding indicates that certain early damage to the right brain causes a mild hypofunction of the left hand in natural weak right-handers, which in turn causes the patient to switch to strong right-handedness. To the authors' knowledge, this finding provides the 1st empirical evidence supporting the pathological right-handedness hypothesis. Prior failure to find evidence of pathological right-handedness may reflect the low base rate of natural left-handers rather than true absence of pathological right-handers.
Kim
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Department of Rehabilitation Psychology, Taegu University, South Korea. hongkn@biho.taegu.ac.kr
Yi
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Son
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Kim
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D000328:Adult; D001288:Attention / Q000502:physiology; D001925:Brain Damage, Chronic / Q000503:physiopathology / Q000523:psychology; D004292:Dominance, Cerebral / Q000502:physiology; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D013702:Temporal Lobe / Q000503:physiopathology