Digit symbol substitution test (DSST) is a
neuropsychological test
Neuropsychological tests are specifically designed tasks that are used to measure a psychological function known to be linked to a particular brain structure or pathway. Tests are used for research into brain function and in a clinical setting f ...
sensitive to brain damage,
dementia
Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...
, age and depression.
The test is not sensitive to the location of brain-damage (except for damage comprising part of the visual field). It consists of (e.g. nine) digit-symbol pairs (e.g. 1/-,2/┴ ... 7/Λ,8/X,9/=) followed by a list of digits. Under each digit the subject should write down the corresponding symbol as fast as possible. The number of correct symbols within the allowed time (e.g. 90 or 120 sec) is measured.
The DSST contained in the
Wechsler Adult Intelligence Scale
The Wechsler Adult Intelligence Scale (WAIS) is an IQ test designed to measure intelligence and cognitive ability in adults and older adolescents. The original WAIS (Form I) was published in February 1955 by David Wechsler, as a revision of the ...
is called 'Digit Symbol' (WAIS-R), 'Digit-Symbol-Coding' (WAIS-III), or most recently, 'Coding' (WAIS-IV). Based on
The Boston Process Approach to assessment, in order to examine the role of memory in Digit-Symbol-Coding performance, WAIS-III (but not WAIS-IV) contains an optional implicit learning test: after the Digit Symbol-Coding test paired and free recall of the symbols is assessed.
[
]
The
National Health and Nutrition Examination Survey
The National Health and Nutrition Examination Survey (NHANES) is a survey research program conducted by the National Center for Health Statistics (NCHS) to assess the health and nutritional status of adults and children in the United States, and t ...
(
NHANES
The National Health and Nutrition Examination Survey (NHANES) is a survey research program conducted by the National Center for Health Statistics (NCHS) to assess the health and nutritional status of adults and children in the United States, and t ...
) administered the DSST to over three thousand participants 60 years and older in 2011–2014. Trained interviewers administered the test at the end of a face-to-face private interview in an examination center and two interviewers independently scored the test. An extensive analysis of these data has been published.
Scores (mean, 25th percentile, 75th percentile) declined with age: 60-69y: 57, 46, 68; 70-79y: 48, 38, 68; 80+y: 40, 29, 49.
See also
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Four boxes test
References
External links
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{{Neuropsychology tests
Neuropsychological tests