Abstract

Clinical neuropsychology is a relatively new and increasingly significant field of study. In 1979 the American Psychological Association created a special division for members interested in clinical neuropsychology, signaling the growing interest in the applied study of brain-behavior relationships. Clinical neuropsychology had its beginnings in many different disciplines, including experimental psychology, cognitive psychology, clinical psychology, neurology and neurophysiology. Thus it is truely an interdisciplinary science, diverse in methodology and theoretical models. In order to present important issues in neuropsycho logical research, researchers have identified three basic dimensions. The three dimensions include: 1) subject variables (normal subject groups: age, education, occupation, intelligence, socioeconomic siatus, handedness, sex, psychological factors, medical controIs, developmental disabilities; psychiatric patients; malingerers; brain-damaged patients), 2) measurement issues (psychometrics, behavioral assessment, physiological measures), and 3) time parameters. The interaction of these design problems-subject variables, measurement, and time parameters-complicates any experimental or quasi-experimental study of brain-behavior relationships in clinical neuropsychology. Unlike a pure experimental model, in the typical neuropsychological investigation, many independent variables are uncontrollable, such as type, magnitude and site of lesion, behavioral effects, and patient characteristics, thereby increasing error variance. Recognition of methodological issues can certainly lead to more careful planning of one's research, including collection of comprehensive subject data, multidimensional measurement, follow-up testing, and consideration of statistical problems.