Neurophysiologic correlates of cross-language perception of phonetic categories
Anu Sharma, Michael F. Dorman · The Journal of the Acoustical Society of America · 1999
This study examined neurophysiologic correlates of categorical perception of native and non-native phonetic categories. Behavioral and electrophysiologic responses were obtained in Hindi and English listeners, in response to a stimulus continuum of naturally produced, bilabial CV stimuli that differed in VOT from −90 to 0 ms. These speech sounds constitute phonenically relevant categories in Hindi but not in English. As expected, the native Hindi listeners identified the stimuli as belonging to two distinct phonetic categories (/ba/ and /pa/) and their discrimination of a stimulus pair across categories was more accurate than their discrimination of a stimulus pair (of equal VOT change) within the /pa/ category. English listeners discrimination accuracy of within- and across-category pairs was at chance. N100 and MMN cortical-evoked potentials which are considered neural indices of preattentive sensory encoding and discrimination were measured. A double-peaked N100 was elicited in English and Hindi listeners. The first peak was elicited by syllable onset, while the latency of the second peak reflected the VOT lead time. Hindi listeners exhibited robust MMNs for the within- and across-category pairs, while English speakers did not, suggesting that the central sensory representation of certain phonetic categories is at least partially altered by linguistic experience. latency of the second peak reflected the VOT lead time. Hindi listeners exhibited robust MMNs for the within- and across-category pairs, while English speakers did not, suggesting that the central sensory representation of certain phonetic categories is at least partially altered by linguistic experience.