Auditory-Visual Speech Processing (AVSP'99)

August 7-10, 1999
Santa Cruz, CA, USA

Activation In Auditory Cortex by Speechreading in Hearing People: fMRI Studies

Ruth Campbell (1), G. Calvert (2), M. Brammer (3), M. MacSweeney (1), S. Surguladze (3), P. McGuire (3), B. Woll (4), S. Williams (1), E. Amaro (5), A.S. David (3)

(1) University College London, UK
(2) FMRIB Centre, University of Oxford, UK
(3) Institute of Psychiatry, London, UK
(4) City University, London, UK
(5) University of Sao Paolo, Brasil

Which brain networks support simple silent speechreading (identifying spoken numbers by eye alone)? We summarize recent fMRI findings that show auditory cortex is reliably activated by seen speech. Activation of these regions is robust under numerous testing conditions, and parts of the network are specific to speechreading rather than viewing faces performing rhythmic lower face movements that cannot be construed as speech (facial gurning). In one adult with a longstanding malfunction of auditory cortex, speechreading was both functionally impaired and cortically anomalous. Areas traditionally described as auditory cortex are probably specialized for the perception of natural segmented language, rather than for the perception of heard signals.

Full Paper

Bibliographic reference.  Campbell, Ruth / Calvert, G. / Brammer, M. / MacSweeney, M. / Surguladze, S. / McGuire, P. / Woll, B. / Williams, S. / Amaro, E. / David, A.S. (1999): "Activation in auditory cortex by speechreading in hearing people: fMRI studies", In AVSP-1999, paper #7.