Using a clinically aggressive sample to examine the association between impulsivity, executive functioning, and verbal learning and memory.

Impulsive behavior has been conceptualized from several vantage points including biological, sociological and psychological phenomenon. A comprehensive review of the empirical literature revealed that there is a paucity of research examining the association between working memory, executive functioning and impulsivity. A total sample of 170 aggressive outpatient participants was recruited for the study. Participants were administered a comprehensive neuropsychological battery. Principal components analysis of the 19 CVLT indices revealed five factors, accounting for 68% of the total variance. Results from the canonical correlation revealed one significant canonical variate with loadings from three CVLT factors (General Verbal Learning, Response Discrimination, and Proactive Interference), two executive functioning measures (Trail Making Test and Controlled Oral Word Association Test), and one impulsivity subscale (Attentional Impulsiveness). The findings of this study underscore the importance of memory functioning in determining impulsive aggressive behavior.

Characterizing aggressive behavior in a forensic population.

The concept of a dichotomous versus a continuous aggression model continues to be debated within the research literature. The Impulsive/Premeditated Aggression Scale (IPAS; M. S. Stanford, R. J. Houston, C. W. Mathias, et al., 2003) is a newly developed self-report instrument designed to classify an individual's aggressive behavior as predominantly premeditated or predominantly impulsive. The IPAS consists of 30-items that are scored on a 5-point Likert scale. This study used a nonrandom sample of convenience (N = 85) from a forensic state hospital. Principal-components analysis of the 30 items revealed 2 distinct factors (Impulsive and Premeditated Aggression), which accounted for 33% of the variance. The results of this study further validate the bimodal classification of aggression through its application to a forensic sample. The implications for general assessment, diagnosis, and treatment are discussed.