Phonological similarity effects in memory for serial order of cued speech

Experiment I investigated memory for serial order by congenitally, profoundly deaf individuals, 6-22 years old, for words presented via Cued Speech (CS) without sound. CS is a system that resolves the ambiguity inherent in speechreading through the addition of manual cues. The phonological components of CS are mouth shape, hand shape, and hand placement. Of interest was whether the recall of serial order was lower for lists of words similar in both mouth shape and hand placement, or similar in mouth shape only, or in hand placement only than for control lists designed to minimize these similarities. Deaf participants showed lower performance on the three similar lists than the control lists, suggesting that deaf individuals use the phonology of CS to support their recall. In Experiment II, the same lists were administered to two groups of hearing participants. One group, experienced producers of CS, received the CS stimuli without sound; the other group, unfamiliar with CS, received the CS stimuli audiovisually. Participants experienced with CS showed no effect of hand placement similarity, suggesting that this effect may be related to the linguistic experience of deaf participants. The recency effect was greater in the hearing group provided with sound, indicating that the traces left by auditory stimuli are perceptually more salient than those left by the visual stimuli encountered in CS.