Functional Dissociation of Mismatch Negativity From Late Discriminative Negativity Across the Adult Lifespan.

The mismatch negativity (MMN) is elicited by infrequent acoustic changes (such as pitch, frequency, and duration of tones) and by violations of higher-order, abstract auditory patterns. In these latter cases, the MMN can be accompanied by a lesser-known event-related potential termed the late discriminative negativity (LDN). To date, examination of the LDN has been primarily centered on childhood development; whether the LDN is reliably elicited across the adult lifespan and how its functional significance differs from the MMN remain unclear. This study examined the MMN and LDN recorded from 92 adults (18-86 years, 47 females) elicited by changes in pitch contour within short (500 ms) five-tone sequences. Subsequent incidental memory for the standard and deviant tone sequences was tested against similar lures and dissimilar foils. Data-driven analyses showed that the LDN was reliably visible from young to older adulthood and remained stable through adulthood, in contrast to age-related declines in MMN. Furthermore, MMN amplitude was robustly associated with age and subsequent memory performance, whereas LDN amplitude showed weak and inconsistent associations with age and hearing acuity. Results extend prior developmental work by revealing a reliable LDN throughout adulthood and are consistent with the LDN as a marker of prediction error for higher-order, gestalt properties of auditory perception. Taken together, the MMN and LDN are both generated by discrepancies between incoming sensory input and predicted regularities but are temporally distinct and show differential associations with age and memory performance, suggesting a functional dissociation between early and late indices of oddball detection.