[Disordered behavioral control in psychiatric illnesses. Neurophysiological aspects of impulsive behavior]

Dysfunction of behavioral control represents a central component of many psychiatric disorders and may be connected with self-mutilating and antisocial behavior. However, only a few studies have investigated objective assessment and quantification of impulsive behavior, which is relevant for psychiatric practice and research. Because new techniques enable objective assessment of behavior generation and execution, the current knowledge about neurophysiological aspects of behavioral control is summarized.

The contemporary literature on neuronal mechanisms of initiation and execution of behavior and movements and new neurophysiological methods and findings are discussed in respect to their application in psychiatry.

Behavior, defined as movements of a body in time and space, is the result of cortical and subcortical processes. These consist of two general components: (1) perception and selection of a stimulus and (2) execution of a movement, including decision and planning phases. Planning and execution, modulated by cognition and emotions, are dependent on the balance of inhibitory and excitatory aspects of behavior control. Combined detection of electrical brain activity and kinematic analysis of peripheral movements enables the analysis of control mechanisms.

Impulsiveness and inhibition of behavior depend on neuronal control mechanisms which can be analyzed by neurophysiological methods. Objective assessment of impulsive behavior related to psychiatric disturbances including eating disorders, substance abuse, and personality disorders may clarify underlying neurobiological mechanisms and enable rational pharmaco- and psychotherapeutic interventions.