Substance use/abuse as a predictor to illegal and violent behavior: A review of the relevant literature

The preponderance of the research evidence supports the conclusion that abuse of certain types of illicit drugs, separately from the abuse of alcohol, predisposes to subsequent violent behavior. The relationship of cocaine/crack to violent crime has been established more clearly for users of crack in inner city areas than it has for those who are users of other forms of cocaine in the general population.In regard to any race/ethnic or socioeconomic factors in the relationships between substance use/abuse and violent behavior, most clearly established is that a higher proportion of young Black males, compared to other race/ethnic groups, are actively involved in dealing cocaine/crack in some inner city poverty areas.As for gender differences, the research evidence indicates that alcohol abuse as a predictor to and a precipitant of violent behavior, is more clearly established for males than for females. Drug abuse, as distinct from alcohol abuse, has been found to predict subsequent violent behavior, for females as well as for males. “Co-morbidity,” the combination of substance use with and psychopathology, appears more likely to predict for females to later violent behavior. Psychopathology and mental health problems are less likely to predict occurrence of either violent or criminal behavior in the future than are either alcohol abuse or drug abuse.     

Visual inertia of rotating 3-D objects

Five experiments were designed to determine whether a rotating, transparent 3-D cloud of dots (simulated sphere) could influence the perceived direction of rotation of a subsequent sphere. Experiment 1 established conditions under which the direction of rotation of a virtual sphere was perceived unambiguously. When a near-far luminance difference and perspective depth cues were present, observers consistently saw the sphere rotate in the intended direction. In Experiment 2, a near-far luminance difference was used to create an unambiguous rotation sequence that was followed by a directionally ambiguous rotation sequence that lacked both the near-far luminance cue and the perspective cue. Observers consistently saw the second sequence as rotating in the same direction as the first, indicating the presence of 3-D visual inertia. Experiment 3 showed that 3-D visual inertia was sufficiently powerful to bias the perceived direction of a rotation sequence made unambiguous by a near-far luminance cue. Experiment 5 showed that 3-D visual inertia could be obtained using an occlusion depth cue to create an unambiguous inertia-inducing sequence. Finally, Experiments 2, 4, and 5 all revealed a fast-decay phase of inertia that lasted for approximately 800 msec, followed by an asymptotic phase that lasted for periods as long as 1,600 msec. The implications of these findings are examined with respect to motion mechanisms of 3-D visual inertia.