TY - JOUR
T1 - Neural Correlates of Speech Segregation Based on Formant Frequencies of Adjacent Vowels
AU - Alain, Claude
AU - Arsenault, Jessica S.
AU - Garami, Linda
AU - Bidelman, Gavin M.
AU - Snyder, Joel S.
N1 - Publisher Copyright:
© The Author(s) 2017.
PY - 2017/1/19
Y1 - 2017/1/19
N2 - The neural substrates by which speech sounds are perceptually segregated into distinct streams are poorly understood. Here, we recorded high-density scalp event-related potentials (ERPs) while participants were presented with a cyclic pattern of three vowel sounds (/ee/-/ae/-/ee/). Each trial consisted of an adaptation sequence, which could have either a small, intermediate, or large difference in first formant (I "f 1) as well as a test sequence, in which I "f 1 was always intermediate. For the adaptation sequence, participants tended to hear two streams ("streaming") when I "f 1 was intermediate or large compared to when it was small. For the test sequence, in which I "f 1 was always intermediate, the pattern was usually reversed, with participants hearing a single stream with increasing I "f 1 in the adaptation sequences. During the adaptation sequence, I "f 1-related brain activity was found between 100-250 ms after the /ae/ vowel over fronto-central and left temporal areas, consistent with generation in auditory cortex. For the test sequence, prior stimulus modulated ERP amplitude between 20-150 ms over left fronto-central scalp region. Our results demonstrate that the proximity of formants between adjacent vowels is an important factor in the perceptual organization of speech, and reveal a widely distributed neural network supporting perceptual grouping of speech sounds.
AB - The neural substrates by which speech sounds are perceptually segregated into distinct streams are poorly understood. Here, we recorded high-density scalp event-related potentials (ERPs) while participants were presented with a cyclic pattern of three vowel sounds (/ee/-/ae/-/ee/). Each trial consisted of an adaptation sequence, which could have either a small, intermediate, or large difference in first formant (I "f 1) as well as a test sequence, in which I "f 1 was always intermediate. For the adaptation sequence, participants tended to hear two streams ("streaming") when I "f 1 was intermediate or large compared to when it was small. For the test sequence, in which I "f 1 was always intermediate, the pattern was usually reversed, with participants hearing a single stream with increasing I "f 1 in the adaptation sequences. During the adaptation sequence, I "f 1-related brain activity was found between 100-250 ms after the /ae/ vowel over fronto-central and left temporal areas, consistent with generation in auditory cortex. For the test sequence, prior stimulus modulated ERP amplitude between 20-150 ms over left fronto-central scalp region. Our results demonstrate that the proximity of formants between adjacent vowels is an important factor in the perceptual organization of speech, and reveal a widely distributed neural network supporting perceptual grouping of speech sounds.
UR - http://www.scopus.com/inward/record.url?scp=85010304147&partnerID=8YFLogxK
U2 - 10.1038/srep40790
DO - 10.1038/srep40790
M3 - Article
C2 - 28102300
AN - SCOPUS:85010304147
VL - 7
JO - Scientific Reports
JF - Scientific Reports
M1 - 40790
ER -