TY - JOUR
T1 - Speech-evoked activity in primary auditory cortex
T2 - effects of voice onset time
AU - Steinschneider, Mitchell
AU - Schroeder, Charles E.
AU - Arezzo, Joseph C.
AU - Vaughan, Herbert G.
N1 - Funding Information:
This research was supported in part by Grants DC00657 from NIH, MH06723 from NIMH, 90-31 from the McDonnell-Pew Program in Cognitive Neuroscience, and the Rose F. Kennedy Center at Albert Einstein College of Medicine Core Grant.
PY - 1994/1
Y1 - 1994/1
N2 - Neural encoding of temporal speech features is a key component of acoustic and phonetic analyses. We examined the temporal encoding of the syllables /da/ and /ta/, which differ along the temporally based, phonetic parameter of voice onset time (VOT), in primary auditory cortex (A1) of awake monkeys using concurrent multilaminar recordings of auditory evoked potentials (AEP), the derived current source density, and multiunit activity. A general sequence of A1 activation consisting of a lamina-specific profile of parallel and sequential excitatory and inhibitory processes is described. VOT is encoded in the temporal response patterns of phase-locked activity to the periodic speech segments and by "on" responses to stimulus and voicing onset. A transformation occurs between responses in the thalamocortical (TC) fiber input and A1 cells. TC fibers are more likely to encode VOT with "on" responses to stimulus onset followed by phase-locked responses during the voiced segment, whereas A1 responses are more likely to exhibit transient responses both to stimulus and voicing onset. Relevance to subcortical speech processing, the human AEP and speech psychoacoustics are discussed. A mechanism for categorical differentiation of voiced and unvoiced consonants is proposed.
AB - Neural encoding of temporal speech features is a key component of acoustic and phonetic analyses. We examined the temporal encoding of the syllables /da/ and /ta/, which differ along the temporally based, phonetic parameter of voice onset time (VOT), in primary auditory cortex (A1) of awake monkeys using concurrent multilaminar recordings of auditory evoked potentials (AEP), the derived current source density, and multiunit activity. A general sequence of A1 activation consisting of a lamina-specific profile of parallel and sequential excitatory and inhibitory processes is described. VOT is encoded in the temporal response patterns of phase-locked activity to the periodic speech segments and by "on" responses to stimulus and voicing onset. A transformation occurs between responses in the thalamocortical (TC) fiber input and A1 cells. TC fibers are more likely to encode VOT with "on" responses to stimulus onset followed by phase-locked responses during the voiced segment, whereas A1 responses are more likely to exhibit transient responses both to stimulus and voicing onset. Relevance to subcortical speech processing, the human AEP and speech psychoacoustics are discussed. A mechanism for categorical differentiation of voiced and unvoiced consonants is proposed.
KW - (Monkeys)
KW - Auditory evoked potentials
KW - Categorical perception
KW - Current source density
KW - Multiunit activity
KW - Phonetics
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U2 - 10.1016/0168-5597(94)90005-1
DO - 10.1016/0168-5597(94)90005-1
M3 - Article
C2 - 7508851
AN - SCOPUS:0028049227
SN - 0168-5597
VL - 92
SP - 30
EP - 43
JO - Electroencephalography and Clinical Neurophysiology/ Evoked Potentials
JF - Electroencephalography and Clinical Neurophysiology/ Evoked Potentials
IS - 1
ER -