Perceptual representations of phonotactically illegal syllables.

Listeners often categorize phonotactically illegal sequences (e.g., /dla/ in English) as phonemically similar legal ones (e.g., /gla/). In an earlier investigation of such an effect in Japanese, Dehaene-Lambertz, Dupoux, and Gout (2000) did not observe a mismatch negativity in response to deviant, illegal sequences, and therefore argued that phonotactics constrain early perceptual processing. In the present study, using a priming paradigm, we compared the event-related potentials elicited by Legal targets (e.g., /gla/) preceded by (1) phonemically distinct Control primes (e.g., /kla/), (2) different tokens of Identity primes (e.g., /gla/), and (3) phonotactically Illegal Test primes (e.g., /dla/). Targets elicited a larger positivity 200-350 ms after onset when preceded by Illegal Test primes or phonemically distinct Control primes, as compared to Identity primes. Later portions of the waveforms (350-600 ms) did not differ for targets preceded by Identity and Illegal Test primes, and the similarity ratings also did not differ in these conditions. These data support a model of speech perception in which veridical representations of phoneme sequences are not only generated during processing, but also are maintained in a manner that affects perceptual processing of subsequent speech sounds.