Neuroimaging and Neuropsychological Assessment

Abstract

Within the first 30 years of this century, patients with various forms of brain damage began to be evaluated with test instruments designed to assess “mental abilities” (Anastasi, 1988). In 1935 Ward Halstead began his systematic research in brain—behavior relationships which, in turn, led one of his students, Ralph Reitan, to initiate his clinical research and standardization of tests designed specifically to evaluate brain function through behavior (Reitan & Wolfson, 1985). During this period, the typical methodology in defining “brain damaged” or “organic” groups under investigation was to take cases with objective physical exam criteria (e.g., paralysis on one side of the body following a stroke or head injury, specific type of EEG abnormality, etc.) or patients who had been operated on neurosurgically wherein the brain could be directly inspected (see review by Bigler, Yeo, & Turkheimer, 1989). The obvious limitations of such methodologies lie with their inability to specifically quantify exact areas/regions of structural brain damage. What this fostered early in this century and through the decades up until the 1970s was a unitary concept of “brain damage” or “organicity” (see Bigler & Erfurth, 1983). During this era this conceptualization of “brain injury” resulted in a clear lack of precision in defining independent variables (IV) for the study of brain—behavior relationships in humans. This restriction in what could be defined as an IV in the classification of brain injury was due to the lack of any standardized in vivo method to quantify structural brain damage. For example, in 1964 Reitan stated:

Even though a surgeon’s instruments may impose themselves upon the situation in one way or another, the underlying condition of pathology is inevitably difficult to describe in complete or fully accurate terms. Consequently, many unknowns are undoubtedly present to influence the variance of psychological measurements even in the best-designed investigations. (pp. 295–296)