Behavioural data suggests that the processing of auditory, visual and audiovisual speech and biological motion signals may be subserved by specialised processing centres (e.g. [1,2.3]).

We conducted an fMRI study to investigate which areas are involved in the processing of auditory (A), visual (V) and audio-visual (AV) speech, biological motion and scrambled (meaningless) signals.

A localiser experiment was conducted to identify areas that responded to unimodal (A,V) and bimodal (AV) stimuli. Conjunction analysis showed that the pSTS and premotor areas bilaterally responded strongly to speech and biomotion but less to scrambled motion signals. Audiovisual interactions (AV > A+V) were seen in parietal/occipital sulcus, the superior frontal sulcus and the anterior STS.

The areas identified in the first experiment are used as the basis for a region of interest analysis in a second experiment where consistent and inconsistent audiovisual stimuli were presented. We find significantly increased activity in the STS for inconsistent AV stimuli than for matching auditory and visual signals.


[1] Liberman, MIT Press, 1996
[2] Servos et al., Cereb. Cortex, 2002
[3] Tuomainen,Cognition, 96, 2005