The effects of handedness on event-related potentials in a rhyme-matching task.

Event-related potentials (ERPs) were recorded from one midline and three pairs of homotopic lateral sites while subjects determined whether or not sequentially presented words rhymed. ERPs from 11 left-handed males with a family history of sinistrality were compared with those from 12 right-handers, none of whom had such a family history. As in previous work (e.g. Rugg, M. D. Neuropsychologia 22, 435-443, 1984) the slow negative wave developing during the interval in which subjects waited for the final word was more negative from left-hemisphere electrodes, and the rhyme/non-rhyme differences in the ERPs following this word were greater over the right hemisphere. Neither of these asymmetries differed between the left and right-handers. Possible reasons for the occurrence of these ERP asymmetries during rhyme-matching are discussed, and it is suggested that the aspect(s) of linguistic processing tapped by this task, and influencing concurrently recorded ERPs, may be similarly lateralised in the brains of left- and right-handers.