Emotional processing and frontal asymmetry in impulsive aggressive individuals

• Impulsive aggressors have more right frontal activity at rest than controls.
• Impulsive aggressors have more right frontal activity during emotional stimuli.
• Impulsive aggressors have difficulty responding to emotional stimuli.

Right frontal cortical activity, thought to reflect increased activity in withdrawal-related systems, has been observed in angry and anxious samples. The current study attempted to examine this effect in impulsive aggressive individuals (IAs) and nonaggressive controls. Impulsive aggression is a reactive violent response characterized by loss of behavioral control and previous physiological studies have found IAs have sensory and informational processing deficits. In Study 1, undergraduate volunteers (n = 10 IAs, n = 14 controls) completed a resting EEG and IAs showed more right frontal cortical activity than controls at rest. In Study 2, we replicated this result with undergraduate males (n = 15 IAs, n = 15 controls) and demonstrated that not only did IAs have more right frontal activity at rest than controls, controls were able to switch between the behavioral inhibition system (BIS) and behavioral activation system (BAS) depending on exposure to affective stimuli, whereas IAs could not. Results indicated IAs likely have an overactive BIS, and thus have difficulty recognizing emotional stimuli, suggesting a dysfunction in emotional arousal. Future directions are discussed.