Working memory, deafness and sign language.

Working memory (WM) for sign language has an architecture similar to that for speech-based languages at both functional and neural levels. However, there are some processing differences between language modalities that are not yet fully explained, although a number of hypotheses have been mooted. This article reviews some of the literature on differences in sensory, perceptual and cognitive processing systems induced by auditory deprivation and sign language use and discusses how these differences may contribute to differences in WM architecture for signed and speech-based languages. In conclusion, it is suggested that left-hemisphere reorganization of the motion-processing system as a result of native sign-language use may interfere with the development of the order processing system in WM.