Understanding and Preventing Violence, Volume 2: Biobehavioral Influences (1994)
Chapter: PSYCHOPHYSIOLOGIC APPROACH
and communication may contribute to a misinterpretation of events and motives in an interpersonal encounter; this in turn could precipitate a violent encounter. Similarly, poor verbal abilities and communication skills could contribute to peer rejection in childhood, which in combination with other later social and situational factors could predispose to alienation and, ultimately, to violence. Alternatively, left-hemisphere dysfunction could result in verbal deficits that lead to school failure, which in turn could lead to violence. Left-hemisphere dysfunction may, however, be a result (rather than the cause) of violent behavior, since blows to the head and falls may result in concussion and damage to the cortex.
Another major source of damage to the brain that may have profound and irreversible consequences for adaptive behavior is in environmental toxins. Maternal use of ethanol (as in beverage alcohol) has effects on the fetus that may persist for many years, and are manifest in poorer attention at ages 4, 7, and older (Streissguth et al., 1984, 1986, 1989). The effects of lead on cognitive and social adaptation have been the focus of investigation by Needleman and collaborators (1990); even relatively "small" elevations of lead in the body are associated with poor attention, academic failure, and other impairment in life success. Maternal use of cocaine, opiates, and tobacco has also been shown to have a deleterious effect on the neurobehavioral capacities of the infant and developing child. These early effects may be associated, as well, with long-term academic and social failures (summarized in Mirsky and Siegel, in this volume).
Large-scale epidemiologic and prospective studies are required in order to help elucidate the etiologic significance of neuropsychologic impairment for violence. One limitation of neuropsychologic studies, however, is that they are only indirect measures of brain dysfunction; additional statements regarding brain dysfunction in violence can be made on the basis of future studies that combine neuropsychologic testing with electroencephalogram (EEG) and positron emission tomography (PET) measures of brain activity.
PSYCHOPHYSIOLOGIC APPROACH
Neurochemical, neuroanatomic, and neurophysiologic research on violent behavior faces formidable difficulties. Measurement of the central neurologic processes is costly, often invasive, and difficult to implement so as to observe the processes during reactions to transitory situations in the social environment. To cope with these difficulties, an alternative approach to the study of
