title: Impaired verbal short-term memory in Down syndrome reflects a capacity limitation rather than atypically rapid forgetting.
abstract: Individuals with Down syndrome suffer from relatively poor verbal short-term memory. Recent work has indicated that this deficit is not caused by problems of audition, speech, or articulatory rehearsal within the phonological loop component of Baddeley and Hitch's working memory model. Given this, two experiments were conducted to investigate whether abnormally rapid decay underlies the deficit. In a first experiment, we attempted to vary the time available for decay using a modified serial recall procedure that had both verbal and visuospatial conditions. No evidence was found to suggest that forgetting is abnormally rapid in phonological memory in Down syndrome, but a selective phonological memory deficit was indicated. A second experiment further investigated possible problems of decay in phonological memory, restricted to item information. The results indicated that individuals with Down syndrome do not show atypically rapid item forgetting from phonological memory but may have a limited-capacity verbal short-term memory system.
authors.affiliation: Department of Experimental Psychology, University of Bristol, Bristol BS8 1TN, UK. h.purser@bristol.ac.uk
authors.forename: Harry R
authors.initials: HR
authors.lastname: M Purser
authors.forename: Christopher
authors.initials: C
authors.lastname: Jarrold
mesh_terms: D000328:Adult; D004314:Down Syndrome / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000453:epidemiology*; D008570:Memory, Short-Term; D009483:Neuropsychological Tests; D010700:Phonetics; D012720:Severity of Illness Index; D013997:Time Factors; D014825:Vocabulary