Visual interference on speech perception is greater at word offset than onset.
Poster Presentation

Sheila Crewther
La Trobe University

Ayla Barutchu
La Trobe University

David Crewther
Swinburne University of Technology

     Abstract ID Number: 99
     Full text: Not available
     Last modified: March 26, 2007
     Presentation date: 07/07/2007 10:00 AM in Quad Maclauren Hall
     (View Schedule)

Abstract
Background: The present study aimed to investigate visual influences on speech perception at word onset and offset in real and pseudos words using the McGurk and Reverse-McGurk Illusions.
Method: Forty-one healthy young adults were allocated into two groups (lip-reading and hearing group). Participants were presented with consonant-vowel-consonant real words and pseudo-words with an audiovisual discrepancy positioned at word onset or offset. Audiovisual discrepancies were produced by dubbing /b/ and /p/ over the lip-movents of /g/ and /k/, respectively. In the hearing and lip-reading conditions participants were instructed to write down what they heard and lip-read, respectively.
Results: The McGurk and the Reverse-McGurk Effects were observed with both real and pseudo words. More responses were consistent with the visual component of the stimuli when the audiovisual discrepancy was positioned at word offset compared to word onset in both real and pseudo words.
Conclusion: The McGurk and Reverse-McGurk Effects are robust illusions that occur with real and pseudo words. The magnitude of the perceptual interference of vision on speech perception is dependent on the position of the audiovisual discrepancy, and is significantly greater at word offset compared to word onset.