Evidence for effects of phonological correspondence between visible speech and written syllables

The present study investigated compatibility effects between written and spoken syllables. Participants saw the syllables "Ba" or "Da" printed on a speaker's mouth that was articulating either /b wedge / or /d wedge /. Participants classified either the printed syllable or the mouth movement by pressing a left or right key. Responses were faster when mouth movement and letters were congruent regardless of imperative stimulus dimension. As the two stimulus dimensions (mouth movements and letters) showed dimensional overlap, but did not overlap with the response, stimulus-response compatibility was ruled out according to some models. It is argued that the compatibility effect was due to the competition of phonological codes at a stage preceding response selection. Also, the results lend support to the view that Stroop-like tasks are ambiguous with regard to the locus of compatibility effects. Stimulus-response and stimulus-stimulus compatibility may be observed.