The test is not sensitive to the location of brain-damage (except for damage comprising part of the visual field).
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 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[5]) contains an optional implicit learning test: after the Digit Symbol-Coding test paired and free recall of the symbols is assessed.
[6][7][8][9] The National Health and Nutrition Examination Survey (NHANES) administered the DSST to over three thousand participants 60 years and older in 2011–2014.