| A heuristic model of the physiological substrate of personality structure was developed from a review of recent neurological and physiological psychology literature. The formulation of the model was based on assumptions that the phylogenetic transition from instinctive responding to self-determined behavior required the evolution of automatic neural mechanisms to insure that the organism would monitor the environment for significant stimuli, be motivated to respond in the presence of those stimuli, and mobilize the appropriate psychological operations to determine the form of that response. Functional elements of these basic mechanisms were identified and a functional meta-system was outlined which would organize the elements and optimize the utilization of lateralized cognitive processes in the interest of assuring the emission of adaptive behavior.; The proposed model suggests that certain psychodiagnostic entities might be classified as hyper- and hypo-dominance spectrum disorders based on the form of dysfunction within the meta-system. The ability of the model to predict membership in diagnostic categories was tested by assigning 42 adult psychiatric inpatient and outpatient subjects to hyper-dominant and hypo-dominant groups by diagnosis, according to the constructs of the model, and comparing performance on instruments shown to be sensitive to right and left cerebral hemisphere dysfunction. The Street Gestalt Completion Test and the Object Assembly, Similarities, and Information Subtests of the Wechsler Adult Intelligence Scale-Revised were administered to each subject. An abbreviated form of the Minnesota Multiphasic Personality Inventory (MMPI) was used to compare symptomology between groups.; Significant between-group differences (p < 0.001) in the ratios of test scores sensitive to right versus left cognitive functioning were found in the predicted directions, while the groups did not differ in overall performance on the instruments. Significant differences (p < 0.005) in the ratios of selected MMPI clinical scales, in the predicted direction, provided further support for the hypothesized relationship between lateralized cognitive functioning, symptomology, and diagnosis.; It was concluded that the proposed model provides tenable and potentially useful operational definitions of personality functions and psychopathology. Results were discussed in terms of their implications for psychotherapeutic interventions and additional methods to test the validity of the model. |
