P300, handedness, and corpus callosal size: gender, modality, and task

The P300 event-related potential (ERP) was elicited in left- and right-hand ed young adult male and female subjects (n = 20/group), with auditory and v isual stimulus modalities from single-stimulus and oddball tasks. P300 ampl itude was larger across all conditions for left- compared to right-handed s ubjects at anterior and central electrode sites. P300 latency was shorter a cross all conditions for left- compared to right-handers. Task type did not affect the ERP handedness differences. Male and female subjects demonstrat ed comparable ERP handedness effects, although smaller P300 components were obtained for males compared to females. When considered in the context of previously reported corpus callosal size differences for left- vs. right-ha nded and male vs. female participants, the findings suggest that the P300 r eflects callosal size and inter-hemispheric transmission efficacy. (C) 1999 Elsevier Science B.V. All rights reserved.