Cognitive Event-Related Potential Responses Differentiate Older Adults with and without Probable Mild Cognitive Impairment.

Background: Older adults rarely seek cognitive assessment, but often visit other healthcare professionals (e.g., audiologists). Noninvasive clinical measures within the scopes of practice of those professions sensitive to cognitive impairment are needed. Purpose: This study examined the differences of probable mild cognitive impairment (MCI) on latency and mean amplitude of the P3b auditory event-related potential. Method: Fifty-four participants comprised two groups according to cognitive status (cognitively normal older adults [CNOA], n = 25; probable MCI, n = 29). P3b was recorded using an oddball paradigm for speech (/ba/, /da/) and non-speech (1000, 2000 Hz) stimuli. Amplitudes and latencies were compared from six electrodes (FPz, Fz, FCz, Cz, CPz, Pz) between groups across stimulus probability and type. Results: CNOA participants had larger P3b mean amplitudes for deviant stimuli than those with probable MCI. Group effects of latency were isolated to deviant stimuli at FCz only when those with unclear P3bs were included. Findings did not covary with age or education. Overall, CNOAs showed a large P3b oddball effect while those with probable MCI did not. Conclusions: P3b can be used to show electrophysiological differences between older adults with and without probable MCI. These results support the development of educational materials targeting professionals using auditory-evoked potentials.