Auditory and Visual Recognition Memory in Normal Aging and Parkinson's Disease: An Event-Related Potential Study

Recognition memory was studied In the normal subjects and patients with Parkinson's disease (PD) using continuous auditory and visual recognition memory tasks and event-related potentials (ERPs). In both auditory and visual tasks, the accuracy of old/new responses for words or faces was decreased in normal elderly subjects and decreases even in patients with PD compared to the normal young subjects. In the auditory task, ERP repetition effects were found in the normal young subjects at lags 0,1 and 6, while no repetition effects were evident for lag 6 repetition in the normal elderly subjects and patients with PD. There was a significant difference in ERP amplitudes for new words between normal elderly subjects and patients with PD. In the visual task, both normal groups showed the ERP repetition effect for lag 0 repetition, while the effect in the PD group was not noted even for the lag 0 repetition. The PD patients showed a more positive ERP amplitude than control subjects. Our data suggest that recognition memory for both auditory and visual stimuli declines in normal advancing age and declines even more in patients with PD. In addition, recognition memory deficits in PD may result, at least partly from the impairment of context integration process.