J. Devin McAuley
Dept. of Comput. Sci., Cognitive Sci. Prog., Indiana Univ., Bloomington, IN 47405
A ``biologically inspired'' entrainment mechanism is presented which captures certain aspects of human time perception. The adaptive oscillator model has three main properties: (1) a preferred oscillation period, (2) a gradient-descent procedure which incrementally adapts this period so that the oscillator becomes synchronized with ``rhythmic'' aspects of the stimulus pattern, and (3) a decay term which drives the system back toward its preferred period. To compare model performance to human data, the adaptive oscillator is trained using a simulated 2AFC adaptive-tracking procedure to discriminate tempo changes across a range of interonset intervals (100--1500 ms). It has been shown that human subjects, performing the task described above, exhibit maximum tempo sensitivity between 300--800 ms; increasing the number of isochronous intervals improves thresholds in a roughly uniform way across the investigated range of interonset intervals [Drake and Botte, Percept. Psychophys. 54(3), 277--286 (1993)]. The performance of the model provides a qualitative match to the Drake and Botte data in a more biologically plausible manner than the ``multiple-look'' model proposed by these authors. [Work supported by NIMH.]