Theoretical and Review Articles
Working Memory for Sign Language: A Window Into the
Architecture of the Working Memory System
Margaret Wilson
Karen Emmorey
The Salk Institute for Biological Studies
Traditionally, working memory has been divided into two
major domains: verbal and visuo-spatial. The verbal domain
of working memory can be characterized either by its relationship
to language or by its grounding in auditory processing.
Because of this ambiguity, languages that are not auditory
and vocal (i.e., signed languages) pose a challenge to
this conception of working memory. We describe several experiments
with deaf users of American Sign Language (ASL)
that explore the extent to which the architecture of working
memory is determined by the constraints of auditory and visual
processing and the extent to which it is determined by the
characteristics of language. Various working memory effects
were investigated: phonological similarity, word length, and
articulatory suppression. The pattern of evidence strongly
supports the existence of a sign-based "rehearsal loop"
mechanism parallel to the speech-based rehearsal loop. However,
we also discuss evidence pointing to differences between
the speech loop and the sign loop from forward and backward
digit span tasks with deaf and hearing subjects. Despite their
similarities based on linguistic properties, the speech loop
and the sign loop appear to diverge due to the differing processing
demands of audition and vision. Overall, the results
suggest that the architecture of working memory is shaped
both by the properties of language structure and by the constraints
imposed by sensorimotor modality.
