Face and mouth inversion effects on visual and audiovisual speech perception

Three experiments examined whether image manipulations known to disrupt fac e perception also disrupt visual speech perception. Research has shown that an upright face with an inverted mouth looks strikingly grotesque whereas an inverted face and an inverted face containing an upright mouth look rela tively normal. The current study examined whether a similar sensitivity to upright facial context plays a role in visual speech perception. Visual and audiovisual syllable identification tasks were tested under 4 presentation conditions: upright face-upright mouth, inverted face-inverted mouth, inve rted face-upright mouth, and upright face-inverted mouth. Results revealed that for some visual syllables only the upright face-inverted mouth image d isrupted identification. These results suggest that upright facial context can play a role in visual speech perception. A follow-up experiment testing isolated mouths supported this conclusion.