ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

2pPP42. Temporally directed attending in the discrimination of tempo: Further support for an entrainment model.

J. Devin McAuley

Dept. of Comput. Sci., Cognitive Science Program, Indiana Univ., Bloomington, IN 47405

Gary R. Kidd

Dept. of Speech and Hear. Sci., Indiana Univ., Bloomington, IN 47405

The effect of deviations from temporal expectations on tempo discrimination was investigated using four-tone isochronous sequences. On each trial, a standard sequence was followed by a comparison sequence that was slightly faster or slower than the standard. Listeners judged which sequence was faster. Temporal deviations consisted of advancing or delaying the onset of the comparison pattern in relation to an onset predicted by an extension of the periodicity of the standard (i.e., an ``expected'' onset, based on an entrainment model's predictions). The interonset-interval in the standard sequence was always 400 ms, and the onset of the comparison sequence was manipulated in relation to an ``expected'' interval of 800 ms between the onset of the last tone of the standard sequence and the onset of the comparison sequence. Discrimination thresholds were determined for conditions in which the comparison pattern onset was early, late, or at the expected temporal location. Thresholds for ``early'' conditions were found to be significantly higher than for the ``expected'' condition, but this was not the case for ``late'' conditions. These data will be compared with the quantitative predictions of an entrainment model [McAuley and Kidd, 3257 (1994)]. [Work supported by NIMH and NIDCD.]