Altered auditory repetition suppression and MMNm in relation to cognitive tests in older adults.

Cognitive changes with aging have been connected to deficiency in early-stage cortical repetition suppression (RS) and mismatch negativity (MMN). Here, we intended to investigate age-associated alterations of auditory RS and MMN by using a roving standard paradigm, and examine their relations to cognitive performances. Twenty-two young and 22 elderly adults were recorded with a magnetoencephalography. The Chinese Version Verbal Learning Test (CVVLT) and Trail Making Test (TMT) were administered to the older group. Compared to the younger, the elderly exhibited reduced magnitudes of P50m RS in temporal region, and of N100m RS in fronto-temporo-parietal networks. Weaker MMNm responses were also observed. Moreover, practice time of TMT B-A was significantly negatively correlated to magnitude of RS in frontal areas. These findings suggested an age-related decline of early-stage auditory information processing. Conclusively, in the elderly, frontal lobe plays a role in the modulation of automatic cortical filtering and competence of attentional shifting.