Visual Perception of Glides Versus Vowels: The Effect of Dynamic Expectancy

Does the visual perception of glides require a d y n a m i c representation? In our previous experiments on the visual perception of rounding, we argued against the mandatory status of dynamic representations for visual vowels. In this paper, we focus on a specifically temporal contrast between the French vowel [y] and the corresponding [ÿ] glide. Results are twofold. First: for subjects who use this contrast, we demonstrate that the duration of the static phase of rounding provides a basic correlate of the vowel vs. glide identification. Second: a gating experiment indicates that the intrinsically dynamic nature of the glide is not exploited until subject expectancy is oriented towards motion processing. Again we cannot support an exclusive visual dynamic representation neither for vowels nor glides.