more adequately define the error involved in clinical neuropsychological assessment.
The validity of clinical neuropsychological assessment techniques can be more rigorously addressed using the framework of traditional test theory as well as the framework of more innovative approaches. In addition to specifying and limiting the populations in which valid conclusions can be drawn using a certain assessment instrument, we should choose our validation criteria with consideration of the question to be answered. In other words, a broader and more thoughtful choice of external validation criteria is needed in the research conducted. Rather than assuming that noncognitive variables have minimal impact on neuropsychological performance, these variables should be studied explicitly.
It is puzzling that clinical neuropsychological assessment and psychophysiological assessment have not overlapped to a greater extent. Both assessment paradigms utilize the central nervous system as the mediating operator. There are some intriguing data suggesting that inclusion of psychophysiological data can augment the methods of the neuropsychological evaluation. Damasio, Tranel, and Damasio ( 1990) compared a small (N = 5) group of participants with bilateral lesions in the orbital and lower mesial frontal lobes with participants with lesions in other parts of the cortex and control participants. The measure of interest was electrodermal response to pictures with strong implied meanings (e.g., mutilation, nudity). The bifrontal lesion subjects were deficient in eliciting somatic markers in the form of electrodermal amplitude. This set of results may help explain why bifrontal lesion subjects may have difficulty in making social judgments even though their performance on standard neuropsychological tests may be adequate.
In general, a broader conceptualization of the components of validity and of the methods of evaluating these components will help advance the field. Typically, the components have been thought of as monolithic information; however, it is likely that the relations among variables will need to be investigated across the age span, a notion to which the previous discussions have only alluded. Finally, the newer categories of ecological validity and descriptive validity will increase our knowledge of test interpretation if future work provides empirical explication.
Adams W., & Sheslow D. ( 1990). Wide range assessment of memory and learning: Administration manual. Wilmington, DE: Jastak.