Categorical Perception of Consonants and Vowels: Evidence from a Neurophonetic Model of Speech Production and Perception

While the behavioral side of categorical perception in speech is already well investigated, little is known concerning its underlying neural mechanisms. In this study, a computer-implemented neurophonetic model of speech production and perception is used in order to elucidate the functional neural mechanisms responsible for categorical perception. 20 instances of the model ("virtual listeners/speakers") underwent a speech acquisition training procedure and then performed behavioral tests, i.e. identification and discrimination experiments based on vocalic and CV-syllabic speech stimuli. These virtual listeners showed the expected behavioral results. The inspection of the neural organization of virtual listeners indicated clustering in the case of categorical perception and no clustering in the case of non-categorical (continuous) perception for neurons representing the stimuli. These results highlight a possible neural organization underlying categorical and continuous perception.

[1]  James L. McClelland,et al.  Categorization and discrimination of nonspeech sounds: differences between steady-state and rapidly-changing acoustic cues. , 2004, The Journal of the Acoustical Society of America.

[2]  M. V. Velzen,et al.  Self-organizing maps , 2007 .

[3]  Terry G. Halwes,et al.  Discrimination in speech and nonspeech modes , 1971 .

[4]  P. Kuhl.  Early language acquisition: cracking the speech code , 2004, Nature Reviews Neuroscience.

[5]  Satrajit S. Ghosh,et al.  Neural modeling and imaging of the cortical interactions underlying syllable production , 2006, Brain and Language.

[6]  Bernd J. Kröger,et al.  Towards a neurocomputational model of speech production and perception , 2009, Speech Commun..

[7]  Anna Esposito.  Verbal and Nonverbal Communication Behaviours, COST Action 2102 International Workshop, Vietri sul Mare, Italy, March 29-31, 2007, Revised Selected and Invited Papers , 2007, COST 2102 Workshop.

[8]  J. Rauschecker,et al.  Vowel sound extraction in anterior superior temporal cortex , 2006, Human brain mapping.

[9]  David A. Medler,et al.  Cerebral Cortex doi:10.1093/cercor/bhi040 Cerebral Cortex Advance Access published February 9, 2005 , 2022 .

[10]  P. D. Eimas,et al.  The Relation between Identification and Discrimination along Speech and Non-Speech Continua , 1963 .

[11]  S. Grossberg,et al.  Neural network models of categorical perception , 2000, Perception & psychophysics.

[12]  B. C. Griffith,et al.  The discrimination of speech sounds within and across phoneme boundaries. , 1957, Journal of experimental psychology.

[13]  S. L. Campbell,et al.  Frequency and frequency-ratio resolution by possessors of absolute and relative pitch: examples of categorical perception. , 1994, The Journal of the Acoustical Society of America.

[14]  Peter Birkholz,et al.  A Gesture-Based Concept for Speech Movement Control in Articulatory Speech Synthesis , 2007, COST 2102 Workshop.

[15]  Randall D. Beer,et al.  The Dynamics of Active Categorical Perception in an Evolved Model Agent , 2003, Adapt. Behav..

[16]  A. Liberman,et al.  The Identification and Discrimination of Synthetic Vowels , 1962 .

[17]  A. Braun,et al.  Auditory lexical decision, categorical perception, and FM direction discrimination differentially engage left and right auditory cortex , 2004, Neuropsychologia.