Ordered short-term memory differs in signers and speakers: implications for models of short-term memory.
Capacity limits in linguistic short-term memory (STM) are typically measured with forward span tasks in which participants are asked to recall lists of words in the order presented. Using such tasks, native signers of American Sign Language (ASL) exhibit smaller spans than native speakers ([Boutla, M., Supalla, T., Newport, E. L., & Bavelier, D. (2004). Short-term memory span: Insights from sign language. Nature Neuroscience, 7(9), 997-1002]). Here, we test the hypothesis that this population difference reflects differences in the way speakers and signers maintain temporal order information in short-term memory. We show that native signers differ from speakers on measures of short-term memory that require maintenance of temporal order of the tested materials, but not on those in which temporal order is not required. In addition, we show that, in a recall task with free order, bilingual subjects are more likely to recall in temporal order when using English than ASL. We conclude that speakers and signers do share common short-term memory processes. However, whereas short-term memory for spoken English is predominantly organized in terms of temporal order, we argue that this dimension does not play as great a role in signers' short-term memory. Other factors that may affect STM processes in signers are discussed.
Bavelier
Daphne
D
Department of Brain and Cognitive Sciences, University of Rochester, Meliora Hall Box 270268, Rochester, NY 14627-0268, USA. daphne@cvs.rochester.edu
Newport
Elissa L
EL
Hall
Matt
M
Supalla
Ted
T
Boutla
Mrim
M
D000328:Adult; D001288:Attention; D003638:Deafness / Q000151:congenital / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D010700:Phonetics; D012153:Retention, Psychology; D012193:Reversal Learning; D012691:Serial Learning; D012813:Sign Language; D013067:Speech Perception; D013998:Time Perception; D014706:Verbal Learning