Analysis of substitution test performance using eye movement and video data.

Substitution tests continue to enjoy widespread popularity in applied neuropsychology. Though highly sensitive, these tests lack specificity, and substitution test decrements are often reported in terms that bear little relation to cognitive or other psychological theory. Objectives were to quantify, using eye movement/video analysis, subitem performance elements for the Wechsler Adult Intelligence Scale-Revised (WAIS-R) Digit Symbol Test (DST); to assess the relative contribution of each of these to standard WAIS-R DST performance in a group; and to assess whether wearing the eye-movement measuring equipment interfered with test performance.