Abstract phoneme representations in the left temporal cortex: magnetic mismatch negativity study

We investigated the brain mechanisms enabling one auto-matically discriminate phoneme category irrespective of the large inter-speaker variability in the acoustic features of the voices. For this purpose, subjects were presented with 450 different speech stimuli, each uttered by a different speaker, belonging to three vowel categories, while a 306-channel magnetoencephalogram (MEG) was obtained to record the magnetic counterpart of the mismatch negativity (MMNm), elicited only when sensory memory traces for repetitive sounds are formed in the auditory cortex. Despite this wide acoustic variation, category changes elicited prominent MMNm responses, which were considerably stronger in the left than in the right hemisphere in the right-handed subjects. These results implicate the presence of long-term memory traces for vowels, which can recognize the vowel-specific invariant code enabling correct vowel percept even in the presence of realistic acoustic variation.

[1]  Emmanuel Dupoux,et al.  Electrophysiological Correlates of Phonological Processing: A Cross-linguistic Study , 2000, Journal of Cognitive Neuroscience.

[2]  R. Ilmoniemi,et al.  Magnetoencephalography-theory, instrumentation, and applications to noninvasive studies of the working human brain , 1993 .

[3]  O Bertrand,et al.  Analysis of speech sounds is left-hemisphere predominant at 100-150ms after sound onset. , 1999, Neuroreport.

[4]  R. Ilmoniemi,et al.  Combined mapping of human auditory EEG and MEG responses. , 1998, Electroencephalography and clinical neurophysiology.

[5]  Risto Näätänen,et al.  Neuronal populations in the human brain extracting invariant relationships from acoustic variance , 1999, Neuroscience Letters.

[6]  I. Winkler,et al.  ‘Primitive intelligence’ in the auditory cortex , 2001, Trends in Neurosciences.

[7]  M. Tervaniemi,et al.  Neural representations of abstract stimulus features in the human brain as reflected by the mismatch negativity. , 1994, Neuroreport.

[8]  G. Dehaene-Lambertz.  Electrophysiological correlates of categorical phoneme perception in adults , 1997, Neuroreport.

[9]  R Näätänen,et al.  Phonetic invariance in the human auditory cortex. , 1993, Neuroreport.

[10]  D. Poeppel,et al.  Auditory Cortex Accesses Phonological Categories: An MEG Mismatch Study , 2000, Journal of Cognitive Neuroscience.

[11]  I. Winkler,et al.  The concept of auditory stimulus representation in cognitive neuroscience. , 1999, Psychological bulletin.

[12]  I. Winkler,et al.  Memory prerequisites of mismatch negativity in the auditory event-related potential (ERP). , 1993, Journal of experimental psychology. Learning, memory, and cognition.

[13]  M Yumoto,et al.  Brain lateralization for mismatch response to across- and within-category change of vowels , 2001, Neuroreport.

[14]  R. Ilmoniemi,et al.  Language-specific phoneme representations revealed by electric and magnetic brain responses , 1997, Nature.

[15]  R. Näätänen.  The perception of speech sounds by the human brain as reflected by the mismatch negativity (MMN) and its magnetic equivalent (MMNm). , 2001, Psychophysiology.

[16]  I. Winkler,et al.  Preattentive extraction of abstract feature conjunctions from auditory stimulation as reflected by the mismatch negativity (MMN). , 2001, Psychophysiology.

[17]  S. Palva,et al.  Discrimination of Speech and of Complex Nonspeech Sounds of Different Temporal Structure in the Left and Right Cerebral Hemispheres , 2000, NeuroImage.