Selective adaptation of VOT in Polish

In order to test the hypothesis that selective adaptation and range effects in speech perception are produced by the same proccesses, we compared the size of range effects and adaptation effects for monolingual Polish and English subjects. Previous work has indicated that Polish speakers show much larger range effects in phonetic categorization of VOT than do English speakers. We therefore tested the adaptation effect of a +70 ms VOT stimulus on the perception of two apical VOT continua (ranging from −70 to +30 and −30 to +70 ms VOT). Eight monolingual Polish and English subjects participated. As in our previous work, Poles showed large range effects in categorizing VOT stimuli. (Their mean boundaries were at −3.4 vs 8.4 ms VOT.) They also showed substantial selective adaptation boundary shifts (mean = 18.2 ms), which were reliably larger than the adaptation effects shown by the English speakers (mean = 7.6 ms). Thus, the Polish speakers' perception of VOT is more sensitive than English speakers' to both selective adaptation and range effects, as a unitary model for adaptation and range effects would predict.