Psychophysical and Electrophysiological Measures of Frequency Modulation Sensitivity: Effects of Age and Interaural Modulator Phase

The results support the hypothesis of diminishing temporal fine-structure processing as a function of age. For behavioral FM detection, middle-age and older adults had poorer thresholds for out-of-phase FM than young adults, with functions for in- and out-of-phase FM converging at a lower rate. For the ACC test, this was demonstrated by reduced intertrial phase coherences in the older participants. Although there were general similarities between the behavioral and electrophysiological data patterns, some differences were observed, and further study is required to clarify underlying mechanism(s). The study broadly demonstrates that objective measures can be used to gauge temporal processing, in parallel to behavioral measures, and so can be applied in situations where subjective assessment is challenging.