Halstead-Reitan Test Battery: a problem of differential diagnosis.

The Halstead-Reitan Test Battery is one of the most widely recognized neuropsychological test batteries. Many claims have been made as to its validity. Despite these claims, doubts persist. A critical review of the literature shows that the battery can separate brain-damaged patients from normal patients, general medical patients, and patients with certain psychiatric disorders. However, the battery cannot separate brain-damaged patients as a group from schizophrenics as a group, though in individual cases there may exist pathognomonic signs indicating brain damage. The impairment index, as a summary score of the basic tests, as well as other "methods of inference," fail at this point. Four alternatives are discussed. First, brain-damaged patients differ from schizophrenic patients not in test performance but in test-taking behavior. Second, the battery is a valid measure of brain damage but has limited applicability. Third, the battery is a measure not of brain damage but of degree of degradation of psychological processes. And fourth, schizophrenics perform poorly on the battery because they have undetected brain damage. Only the third and fourth alternatives appear viable. Both question the validity of the traditional criteria of brain damage. It is argued that future validation studies of the battery should be of construct validation type and not of the criterion-oriented type, as these are defined by Cronbach and Meehl (1955). Possible procedures for construct validation are briefly discussed.