Processing of acoustic and phonological information of lexical tones at pre-attentive and attentive stages

Abstract

While Mismatch Negativity (MMN) and P300 have been found to correlate with the processing of acoustic and phonological information involved in speech perception, there is controversy surrounding how these two components index acoustic and/or phonological processing at pre-attentive and attentive stages. The current study employed both passive and active oddball paradigms to examine neural responses to lexical tones at the two stages in Cantonese speakers, using the paradigm of categorical perception (CP) where the between- and within-category deviants share the same acoustic distance from the standard but differ in the involvement of phonological information. We failed to observe a CP effect in P300, which might indicate that this component doesn’t necessarily index phonological processing, while MMN does, as reflected by the finding of a greater MMN amplitude elicited from the between-category than within-category deviant. Nevertheless, phonological processing might be overridden by acoustic processing among participants who were sensitive to pitch.