Attention resources and visible speech encoding in older and younger adults

Two experiments investigated adult age differences in the distribution of attention across a speaker's face during auditory-visual language processing. Dots were superimposed on the faces of speakers for 17-ms presentations, and participants reported the spatial locations of the dots. In Experiment 1, older adults showed relatively better detection performance at the mouth area than the eye area compared to younger adults. In Experiment 2, in the absence of audible language, both age groups did not differentially focus on the mouth area. The results are interpreted in light of Massaro's (1998, Perceiving talking faces: From speech perception to a behavioral principle. Cambridge, MA: MIT Press) theoretical framework for understanding auditory-visual speech perception. It is claimed that older adults' greater reliance on visible speech is due to a reallocation of resources away from the eyes and toward the mouth area of the face.