Psychometric properties of an adolescent version of the Barratt Impulsiveness Scale-11 for a sample of Italian high school students

The purpose of this study was to extend the development of the Italian version of the Barratt Impulsiveness Scale for use with adolescents. The analyses which led to the development of this version were based on data from 563 high school students. The internal consistency was good (Cronbach alpha=.78). A confirmatory factor analysis identified six first-order factors which converged into two second-order factors, a General Impulsiveness factor and a Nonplanning Impulsiveness factor. The General Impulsiveness factor included motor and attention or cognition items. The second-order factors differed from those obtained with the adult Italian version as well as the American version. Possible reasons for these differences are discussed. The new version correlated significantly with self-report measures of aggression and Attention-Deficit/Hyperactivity Disorder as well as with frequency of alcohol use and cigarette smoking.     

The influence of object size and surface shape on shape constancy from stereo

The failure of shape constancy from stereoscopic information is widely reported in the literature. In this study we investigate how shape constancy is influenced by the size of the object and by the shape of the object's surface. Participants performed a shape-judgment task on objects of five sizes with three different surface shapes. The shapes used were: a frontoparallel rectangle, a triangular ridge surface, and a cylindrical surface, all of which contained the same maximum depth information, but different variations in depth across the surface. The results showed that, generally, small objects appear stretched and large objects appear squashed along the depth dimension. We also found a larger variance in shape judgments for rectangular stimuli than for cylindrical and ridge-shaped stimuli, suggesting that, when performing shape judgments with cylindrical and ridge-shaped stimuli, observers rely on a higher-order shape representation.     

Extinction training regulates neuroadaptive responses to withdrawal from chronic cocaine self-administration

Cocaine produces multiple neuroadaptations with chronic repeated use. Many of these neuroadaptations can be reversed or normalized by extinction training during withdrawal from chronic cocaine self-administration in rats. This article reviews our past and present studies on extinction-induced modulation of the neuroadaptive response to chronic cocaine in the mesolimbic dopamine system, and the role of this modulation in addictive behavior in rats. Extinction training normalizes tyrosine hydroxylase levels in the nucleus accumbens (NAc) shell, an effect that could help ameliorate dysphoria and depression associated with withdrawal from chronic cocaine use. Extinction training also increases levels of GluR1 and GluR2/3 AMPA receptor subunits, while normalizing deficits in NR1 NMDA receptor subunits, in a manner consistent with long-term potentiation of excitatory synapses in the NAc shell. Our results suggest that extinction-induced increases in AMPA and NMDA receptors may restore deficits in cortico-accumbal neurotransmission in the NAc shell and facilitate inhibitory control over cocaine-seeking behavior. Other changes identified by gene expression profiling, including up-regulation in the AMPA receptor aggregating protein Narp, suggest that extinction training induces extensive synaptic reorganization. These studies highlight potential benefits for extinction training procedures in the treatment of drug addiction.     

Presleep attributions about arousal during sleep: nocturnal panic

This study examined the role of presleep attributions about physiological events during sleep in nocturnal panic attacks. Patients who regularly experienced nocturnal panic were physiologically monitored as audio signals were presented during sleep. They were randomly assigned to 1 of 3 conditions: expected, in which signals of intense physiological changes were expected; unexpected, in which signals of intense physiological changes were not expected; or control, involving distinctly different signals unrelated to physiological responses. The unexpected condition led to substantially more self-reported distress and panic attacks. The experimental conditions did not elicit different autonomic reactions, but those who panicked showed stronger physiological responses than those who did not panic. The findings are consistent with a cognitive model of nocturnal panic attacks.     

Perceptions of leader-member exchange: comparison of permanent and temporary employees

This study was done to explore how perceived scores for leader-member exchange varies among temporary employees and permanent employees. Study of 158 subordinates indicated no significant difference between the two member groups.     

Correcting correlation coefficients for group heterogeneity when one variable is a dichotomy

A method is illustrated for estimating correlation coefficients and mean criterion scores in a full-range population from bivariate distributions available in a selected sample when the criterion is a dichotomy. The proposed method requires only the assumptions needed for use of formulas for correcting correlation coefficients for restriction of range when both variables are continuous and is suitable for use when restriction is due to either direct or indirect selection.The research reported in this paper was sponsored by the 6570th Personnel Research Laboratory, AMD, under AFSC Project 7717.