QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, August 5, 2009, 29(31):9819-9825; doi:10.1523/JNEUROSCI.6018-08.2009

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Möttönen, R. Articles by Watkins, K. E. PubMed PubMed Citation Articles by Möttönen, R. Articles by Watkins, K. E.

 Previous Article  |  Next Article 

Behavioral/Systems/Cognitive
Motor Representations of Articulators Contribute to Categorical Perception of Speech Sounds

Riikka Möttönen^1,2 and Kate E. Watkins^1,2

¹Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, United Kingdom, and ²Centre for Functional Magnetic Resonance Imaging of the Brain, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom

Correspondence should be addressed to Dr. Riikka Möttönen, Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford OX1 3UD, UK. Email: riikka.mottonen{at}psy.ox.ac.uk

Listening to speech modulates activity in human motor cortex. It is unclear, however, whether the motor cortex has an essential role in speech perception. Here, we aimed to determine whether the motor representations of articulators contribute to categorical perception of speech sounds. Categorization of continuously variable acoustic signals into discrete phonemes is a fundamental feature of speech communication. We used repetitive transcranial magnetic stimulation (rTMS) to temporarily disrupt the lip representation in the left primary motor cortex. This disruption impaired categorical perception of artificial acoustic continua ranging between two speech sounds that differed in place of articulation, in that the vocal tract is opened and closed rapidly either with the lips or the tip of the tongue (/ba/–/da/ and /pa/–/ta/). In contrast, it did not impair categorical perception of continua ranging between speech sounds that do not involve the lips in their articulation (/ka/–/ga/ and /da/–/ga/). Furthermore, an rTMS-induced disruption of the hand representation had no effect on categorical perception of either of the tested continua (/ba/–da/ and /ka/–/ga/). These findings indicate that motor circuits controlling production of speech sounds also contribute to their perception. Mapping acoustically highly variable speech sounds onto less variable motor representations may facilitate their phonemic categorization and be important for robust speech perception.

---

Received Dec. 18, 2008; revised June 8, 2009; accepted July 8, 2009.

Correspondence should be addressed to Dr. Riikka Möttönen, Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford OX1 3UD, UK. Email: riikka.mottonen{at}psy.ox.ac.uk

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help