Ecologic validity in neuropsychological assessment: prediction of wayfinding.

This study compared the ability of clinical and ecologic simulation measures to predict performance on environment-specific criterion measures of wayfinding. Thirty-one unilateral stroke participants comprised the right and left hemisphere groups (16 patients with left sided and 15 patients with right sided strokes). Participants completed a battery of clinical tasks (e.g., traditional paper-and-pencil measures of visualization, mental rotation, visual memory and spatial orientation), ecologic simulations (e.g., slide route recall and visualization of a model town from differing perspectives) and environment specific criterion tasks (e.g., route recall and directional orientation). The groups were equivalent in age, sex, education, handedness, and weeks since stroke. Both ecologic simulation tasks were found to have fairly good internal consistency and 1 simulation task was significantly related to real world wayfinding. Of the clinical tasks, 1 visual memory test was correlated with a directional orientation criterion task, but none correlated with route navigation ability. Results are consistent with literature purporting the benefits of ecologic simulation tasks as predictors of real world functioning.

Clinical utility of Wechsler Memory Scale-Revised and predicted IQ discrepancies in closed head injury.

Comparisons between Wechsler Memory Scale-Revised (WMS-R) indexes and Wechsler Adult Intelligence Scale-Revised (WAIS-R) IQ scores have been proposed to identify severity of memory deficits. However, many neurologic conditions reduce both intellectual and memory functioning, and thus, examining differences between these scores may be of little value. Closed head injured subjects who completed the WMS-R were divided into either mild injury (MI, n = 41) or moderate/severe (SI, n = 41) injury groups based on trauma severity indicators and were matched on age and level of education. The Oklahoma Premorbid Intelligence Estimation (OPIE), a regression formula that takes into account demographic variables as well as IQ performance, was calculated for each subject. Discrepancy scores were calculated between predicted IQ scores and WAIS-R IQ and WMS-R indexes. SI head-injured subjects displayed significantly larger discrepancies (19 points) between OPIE scores and Delayed Recall Indexes from the WMS-R than the MI subjects (10 points). Significantly larger percentages of subjects in the SI group displayed significant (>SD) reductions in many of the WMS-R and WAIS-R scores from estimates than subjects in the MI group. Comparing current memory functioning to estimates of premorbid intellectual ability appears to be a sensitive indicator of presence and degree of intellectual and memory dysfunction in head trauma patients. Results also provide evidence that estimates of premorbid intellectual ability can serve as estimates of premorbid memory functioning.