This procedure assumes that the subject’s “true” maximum length (ML) span can be assessed by only four list presentations: two at the ML and two above. A second, more serious problem relates to the suboptimal sampling of list lengths that bound the subjects’ maximal DS: testing ceases as soon as the subject misses two lists of the same length. This procedure is relatively inefficient for subjects with normal memory spans (e.g., 7 digits in FS) because eight trials are delivered before the subject reaches list lengths that challenge memory capacity. First, WMS-III testing involves the presentation of two digit lists at each span length, beginning with three digits in FS testing and two digits in BS testing. There are also two problems in the methods used by the Wechsler Memory Scale-III (WMS-III) ( Wechsler, 1997b) to sample digit list lengths.
Digit span wais example code#
Certain digit sequences (e.g., the local telephone area code) may inflate digit span in geographic regions where particular digit sequences are overlearned and underestimate span where digit sequences conflict with previously overlearned strings (e.g., the digit sequence “415” in a region where the local telephone area code is “451”). In addition, the digits in each list are not selected randomly. First, because each list is read aloud by an examiner there are variations in the rate, intensity, emphasis and clarity of digit enunciations on each presentation as well as variations in clarity between different examiners ( Reeves, Schmauder, & Morris, 2000 Silverman, 2007). In traditional DS testing digit salience is influenced by two factors. The total number of lists reported correctly is combined across forward span (FS) and backward span (BS) to produce a Wechsler total correct score.
Digit span wais example trial#
Testing ceases when the subject fails to accurately report either trial at one sequence length or when the maximal list length is reached (9 digits forward, 8 backward). Digit sequences are presented beginning with a length of two digits and two trials are presented at each increasing list length. In each case, digit span is measured for forward and reverse-order (backward) recall of digit sequences. For decades they have been a component of the widely used Wechsler memory scales (WMS) and Wechsler intelligence scales for adults and children ( Wechsler, 1997a, 1997b). Both poorer DSS performance and the presence of perseveration can offer useful clinical information on the context of a thorough evaluation of the aMCI/DAT spectrum.Īlzheimer disease WAIS-IV digit span sequencing working memory.Measures of forward and backward digit span (DS) are among the oldest and most widely used neuropsychological tests of short-term verbal memory ( Richardson, 2007). Discontinuation of DSS due to cross-task perseveration was frequently seen in, although not unique to, the DAT group.
Conclusions: The DS sequencing results differed between the three clinical groups, which is consistent with the hypothesis that working memory declines would be evident on this measure. Digit Span Sequencing was significantly different in each group (DAT < aMCI < SCC), with a high rate of the DAT group showing cross-task perseveration. Results: Those with DAT performed significantly worse for DS Forward, Backward, and Total Score versus those with aMCI and SCC, whose performances were similar. This resulted in a sample of 290 individuals with DAT, 255 with aMCI, and 161 with SCC.
Method: Seven hundred and six individuals were drawn from 1256 consecutive referrals who underwent a standard neuropsychological evaluation and obtained a consensus diagnosis from a neuropsychologist and a neurologist of DAT, aMCI, or having SCC. This study examines performance on DS for individuals from a memory disorder clinic diagnosed with amnestic mild cognitive impairment (aMCI), probable dementia of the Alzheimer type (DAT), or those with subjective cognitive complaints (SCC). Objective: The Digit Span (DS) subtest from the Wechsler Adult Intelligence Scale-4 th Edition (WAIS-IV) was updated to better measure working memory which is potentially clinically relevant as prior unreplicated studies showed that sequencing tasks differentiated normal from neurologic groups.
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