Language laterality in left-handers assessed by unilateral E.C.T.

A method for assessing language laterality (namely testing for dysphasia after unilateral E.C.T. to each side of the head) that has been shown to be reliable in right-handed patients has been used in a series of 24 left-handers free from cerebral disease. Results in these 24 patients, combined with those in 13 patients either tested by a previous method or suffering from organic cerebral disease, indicate that language is predominantly represented in the left hemisphere in about 70 per cent of left-handers. Neither degree of sinistrality as measured by the Oldfield score, nor a positive family history, reliably predicted language laterality.