AGE-DIFFERENCES IN VISUAL-EVOKED POTENTIAL ESTIMATES OF INTERHEMISPHERIC-TRANSFER

Twenty-six younger (ages 18-36 years) and 19 older (ages 60-88 years) healthy right-handed men and women were tested for interhemispheric tr ansfer by using visual evoked potentials to laterally presented checke rboards. Interhemispheric transfer time (IHTT) was estimated by subtra cting latencies for both P100 and N160 peaks of the waveform contralat eral to the stimulus from the waveform ipsilateral to the stimulus for homologous sites. The qualify of interhemispheric transfer was estima ted by comparing peak-to-peak amplitudes for homologous sites. IHTT di d not change across age, but there was a suppression of the waveform o ver the indirectly stimulated hemisphere in the older participants: Th e significance of this finding for age-related changes in functions me diated by the corpus callosum is discussed.