Does sound location influence reaction times to audiovisual speech?
Hanna Puharinen, Kaisa Tiippana, Riikka Möttönen, Mikko Sams
Poster
Last modified: 2008-05-13
Abstract
In IMRF2006 we showed that audiovisual speech perception can be influenced by sound location, depending on the direction of spatial attention. Auditory attention was manipulated by varying the probability of auditory stimulus presentations from different locations (centre, i.e. face location, and 45/90 deg left/right). Attention was directed spatially by presenting the majority (90%) of auditory stimuli from one location. In Experiment 1, the major location was in the centre, which resulted in an enhanced McGurk effect (i.e. conflicting visual speech altered the auditory speech percept) in the centre. In Experiment 2, the major location was 90 deg left, which resulted in a stronger McGurk effect on the left and centre relative to the right side. Now, we show that reaction times in this experiment are affected, too, so that for congruent audiovisual stimuli (matching visual and auditory speech) they are overall shorter than for McGurk stimuli, and specifically they tend to be shorter in the attended location. This suggests that processing speed of matching audiovisual information is faster, and more sensitive to the manipulation of spatial attention than that of conflicting audiovisual information.
