Factors affecting performance on a temporal interval discrimination task during adolescence and young adulthood

Auditory temporal processing typically matures well into adolescence. We investigated the cognitive and neurophysiological factors that affect performance on a temporal interval discrimination task during adolescence and young adulthood (age 10–24 years). Psychometric functions were measured using the method of constant stimuli. Stimuli consisted of two 1-kHz, 15-ms tones separated by a standard interval of 100 ms or a signal interval of 100 ms + Dt. Listeners chose which of the three sounds had the longer interval (3AFC). Results were highly variable, and some listeners of all ages were excluded due to an inability to complete the task or poorly fit psychometric functions. Stepwise regressions were conducted to determine the factors affecting performance. Unexpectedly, thresholds (66.67% correct) did not change with age. However, they were predicted by gender (better thresholds in men), auditory working memory, sustained attention, attention switching, and auditory encoding (amplitude of the N1 and latency of the P1 from the acoustic change complex). Slopes were predicted by log-transformed age (steeper slopes with increasing age), gender (steeper slopes in men), auditory working memory, attention switching, and vocabulary. Neither model predicted more than 40% of the variance, suggesting that other factors contributed to the high variability in performance. [Funded by NIDCD.]