Towards a Heuristic Neuropsychological Model of Adjudicative Competency

This study sought to delineate the neuropsychological processes that undergird the psycho-legal concept of competency to stand trial (CST). Accordingly, we retrospectively examined the relationship between clinical judgments of competence or incompetence of defendants committed to a maximum-security psychiatric facility and neuropsychological measures of cognitive and social intelligence and declarative memory. Results indicated that both groups (competent and incompetent) showed similar levels of depressed cognitive intelligence with Wechsler full-scale IQ levels falling in the upper end of the borderline range. Compared with defendants clinically judged as incompetent, defendants recommended as competent scored significantly higher on measures of social intelligence and episodic memory, with the most pronounced advantage occurring on tests of verbal memory that place heavy demands on encoding, consolidation, and retrieval of aurally presented narrative material. Cognitive capacities in areas of social intelligence and episodic memory may play critical roles in developing a heuristic neuropsychological model of CST. The evaluation of these domains offers implications for the assessment, restoration, and understanding of CST.