Peripheral autonomic changes accompanying learning and reaction time performance in older people.

Heart rate, blood pressure, and electrodermal activity were assessed in old (55 to 70) and young (20 to 35) veterans during their performance on serial learning and reaction time tasks. More older than younger subjects exhibited systolic blood pressure increases during the tasks; baseline heart rate was also slower in the older subjects. However, the phasic electrodermal response of the older Ss during the reaction time task was of smaller magnitude than that of the young Ss, and there were no phasic HR differences between the groups. Learning and psychomotor performance of the older subjects who revealed systolic BP pressor responses was significantly better than that of those who showed depressor responses, but this relationship was not obtained in the younger subjects. These relationships were more pronounced on easier than on more difficult tasks.