Multiple looks and temporal integration

Abstract

Recent research on temporal resolution indicates that a person can listen using a temporal window with a time constant of less than 10 ms. A basic question is how information from these brief “looks” is combined and processed. The initial focus is on the old problem of temporal integration and data are reported from an experiment similar to Zwislocki's two-click experiment [J. Zwislocki, J. Acoust. Soc. Am. 32, 1046–1059 (1960)]. The data are well described by assuming true integration for brief click separations and by assuming two independent looks for separations longer than approximately 10 ms. Thus the data are more consistent with multiple looks than with true, long-duration temporal integration. To account for more general “integration” phenomena, a simple multiple-look strategy is compared with neural summation using spike data recorded from the auditory nerve of chinchilla for CF tones. The decision statistic is either an optimally weighted combination of the spike count from contiguous short bins (looks) or the total spike count summed over the duration of the tone. The time-intensity trading functions (threshold for d′ = I versus duration) for these schemes are very similar. This demonstrates, consistent with intuition, that a multiple-look scheme can show integration-like behavior and that such behavior does not imply true integration. [Work supported by NS12125.]