ASA 125th Meeting Ottawa 1993 May

4pPP3. Serial position effects in temporal pattern discrimination.

Toktam Sadralodabai

Robert D. Sorkin

DeMaris A. Montgomery

Dept. of Psychol., Univ. of Florida, Gainesville, FL 32611

Observers were presented with two successive 8-tone sequences; the task was to discriminate between the temporal patterns defined by the inter-tone intervals in each sequence (average inter-tone interval=50 ms, tone duration=25 ms, tone frequency=1000 or 2500 Hz). The observers had to indicate whether the two patterns on each trial were the same or different. A conditional-on-a-single-stimulus (COSS) technique [B. C. Berg, J. Acoust. Soc. Am. 86, 1743--1746 (1991)] was used to evaluate the salience of each temporal position. The probability of responding DIFFERENT is computed given the magnitude of |t[sub 1,i]-t[sub 2,i]|, the absolute difference between the inter-tone intervals at each serial position (i=1,2,...,7). The temporal information in the first and last positions had the greatest influence on the observer's response. These results have implications for models of temporal pattern discrimination. [Work supported by AFOSR.]