Effects of normal aging on event-related potentials and oscillatory brain activity during a haptic repetition priming task.

This study reports neural repetition effects in young and older adults while performing a haptic repetition priming task consisting in the detection of the bilateral symmetry of familiar objects. To examine changes in event-related potentials (ERPs) and induced brain oscillations of object repetition priming with aging, we recorded EEGs of healthy groups of young (n=14; mean age=29.93 years) and older adults (n=15; mean age=66.4). Both groups exhibited similar behavioral haptic priming across repetitions, although young adults responded faster than the older group. Young and older adults showed ERP repetition enhancement at the 500-900 ms time window. In contrast, only the young participants showed ERP repetition suppression at the 1200-1500 ms segment. The results from the induced oscillations showed more positive amplitudes in young than in older adults at theta, alpha and beta frequencies (4-30 Hz). In addition, we found amplitude modulation related to stimulus repetition in the upper alpha and low beta sub-bands only in young adults (1250-1750 ms).The results suggest that although behavioral priming is spared with age, normal aging affects ERPs and oscillatory responses when performing an incidental priming symmetry detection task with haptically explored objects.