Incidental recall on WAIS‐R digit symbol discriminates Alzheimer's and Parkinson's diseases

Abstract

The purpose of this study was to examine how Alzheimer's (n = 37) and Parkinson's (n = 21) patients perform on the incidental recall adaptation to the Digit Symbol of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) and how such performance is related to established cognitive efficiency and memory measures. This adaptation requires the examinee to complete the entire subtest and then, without warning, to immediately recall the symbols associated with each number. Groups did not differ significantly on standard Digit Symbol administration (90 seconds), but on recall Parkinson's patients recalled significantly more symbols and symbol-number pairs than Alzheimer's patients. Using only the number of symbols recalled, discriminate function analysis correctly classified 76% of these patients. Correlations between age-corrected scaled score, symbols incidentally recalled, and established measures of cognitive efficiency and memory provided evidence of convergent and divergent validity. Age-corrected scaled scores were more consistently and strongly related to cognitive efficiency, whereas symbols recalled were more consistently and strongly related to memory measures. These findings suggest that the Digit Symbol recall adaptation is actually assessing memory and that it can be another useful way to detect memory impairment.

Relationship of ethnicity, age, education, and reading level to speed and executive function among HIV+ and HIV– women: The Women's Interagency HIV Study (WIHS) Neurocognitive Substudy

“…Score was the total number of boxes that were correctly filled within the time limit of 90 seconds. An incidental recall condition was added, in which the code table and previous answers were hidden, the nine symbols were shown, and participants were asked to recall the digits that matched the symbols (Demakis, Sawyer, Fritz, & Sweet, 2001; Shuttleworth-Jordan & Bode, 1995; Joy, Fein, & Kaplan, 2003). …”

Frontal Activity during the Digit Symbol Substitution Test Determined by Multichannel Near-Infrared Spectroscopy

“…Poor performance in the DSST has been reported in various psychiatric and neurological disorders like major depression [7] , dementia of Alzheimer's type [7,9] , solvent abuse [8] , Parkinson's disease [9] , alcohol dependence [10] , Huntington's disease [11] , autism spectrum disorders [12] and schizophrenia [6] . The data of our study suggest pervasive increases in oxyHb in the frontal cortex during the DSST with healthy volunteers.…”

Reduced comparison speed during visual search in late life depression

“…Many of the prior studies defined processing speed based on an aggregation of traditional paper-and-pencil neuropsychological measures in which speed of performance is intertwined with the unique stimulus characteristics and demands of the individual tasks. The task demands of these theoretically identified measures of processing speed were as varied as color naming, symbol encoding, visual scanning, motor praxis, and even incidental memory (e.g., Symbol Digit Modalities Test; Demakis, Sawyer, Fritz, & Sweet, 2001). Tests such as these assess the time it takes to complete a complex, multi-domain cognitive operation, and not processing speed per se .…”