ASA 127th Meeting M.I.T. 1994 June 6-10

4pSP4. The time course of neighborhood and lexical effects in phoneme identification.

Rochelle Newman

James R. Sawusch

Paul Luce

Dept. of Psychol., SUNY at Buffalo, Buffalo, NY 14260

Previously, results were presented suggesting that neighborhood density could have effects similar to those of lexical status in phoneme identification tasks. In a typical task demonstrating a lexical effect, subjects might hear two series, one ranging from ``bag'' to ``pag,'' while the other varied from ``pal'' to ``bal.'' Subjects were more likely to classify the ambiguous stimuli from each series as members of the category which makes a word (they would classify ambiguous items as ``b'' in the bag-pag series but as ``p'' in the pal-bal series). In a similar task where none of the four endpoints were words, it was found that subjects classified the ambiguous items as members of the category which had a greater neighborhood density. Variability in previous lexical reports of effects may have been caused by these neighborhood differences. The results of new experiments will be reported that examined neighborhood effects with lexical items and lexical effects without neighborhood differences, along with a framework for a model that explains these effects and their timecourse. [Work supported by NIDCD Grant No. DC00219 to SUNY at Buffalo and an NSF Graduate Fellowship to the first author.]