Alternation behavior, spatial discrimination, and reversal disturbances following 6-hydroxydopamine lesions in the nucleus accumbens of the rat

The effects of dopaminergic depletion of the nucleus accumbens was tested in various behavioral tasks such as alternation, spatial discrimination, and reversal learning, and in an extinction paradigm in a T maze. Animals with lesions showed impairment of spontaneous alternation behavior, disturbances in the acquisition of spatial discrimination, and great difficulty in reversing previously learned habits. In the extinction phase, experimental animals are unable to adjust their behavior, and continue to choose the previously reinforced arm of the T maze. It is suggested that the nucleus accumbens plays an important role in the transition of motivation into action, and that dopamine has a facilitatory influence on the mediation of these processes.     

The Egocentricity Index and Self-Esteem in court ordered psychiatric evaluations

An attempt was made to test the hypothesis that the Egocentricity Index (Exner, 1974), a ratio which incorporates pair and reflection responses, is related to self-esteem. Sixty criminal defendants referred for psychiatric evaluation were routinely administered the Rorschach. After all other testing was completed the subjects were asked to complete the Coopersmith Self-esteem Inventory. Results found no significant relationships between the Egocentricity Index and self-esteem as measured by the Coopersmith. It was recommended that the Egocentricity Index not be used as a measure of self-esteem until research evidence to support its use in this manner is provided.     

Juvenile homicide: The need for an interdisciplinary approach

Most of the empirical literature on juvenile homicide has emerged from the clinical experience of mental health professionals who have diagnosed and/or treated youngsters who killed. After a critical review of this literature, data on 787 juvenile homicide offenders are presented and discussed. These data indicate that intrafamilial killings represent but a small fraction of all homicides perpetrated by juveniles and that there are clear differences between intrafamilial and extrafamilial juvenile homicides.     

Adjustment to rape

This questionnaire study of rape victims' reactions, causal attributions for the rape, coping behaviors after the rape, and psychological adjustment to the rape were examined. As in previous research, high levels of behavioral and characterological self-blame for rape were found. Contrary to prior hypotheses, behavioral self-blame was not associated with good adjustment. Rather, both behavioral and characterological self-blame were associated with poor adjustment. Societal blame was the only causal attribution for rape that was unassociated with adjustment. Remaining at home and withdrawing from others were both associated with poor adjustment, and the use of stress reduction techniques was associated with good adjustment. The implications of the results for theories of victimization and for clinical interventions with rape victims are discussed.     

Real and virtual features in texture perception

The texton theory of preattentive texture perception was recently adopted over a prior model based on the global computation of dipole statistics. It is shown here that the dipole model remains a necessary adjunct unless the texton theory is modified to distinguish real from virtual features of texture perception.     

Does placebo response mediate runner's high?

It is proposed that runner's high is mediated by increased endorphin release as induced by placebo responses arising from subjective expectancies and setting.     

Disturbances in exploratory behavior and functional recovery in the Y and radial mazes following dopamine depletion of the lateral septum

The effects of 6-hydroxydopamine (6-OHDA) injected into the lateral septum in rats were investigated for spontaneous alternation behavior in a Y maze and for spatially oriented behavior in an 8-arm radial maze. The performance of the animals in these tests was assessed under two physiological states, food-satiated and food-deprived. The selective depletion of septal dopaminergic concentrations leads to behavioral disturbances in both the Y and the radial mazes. These deficits disappeared when the animals with 6-OHDA lesions were food-deprived. These results confirm other studies from our laboratory and support two conclusions. First, lesions of dopaminergic neurons lead to behavioral impairments which resemble those found after the total lesion of the structure they innervate. Second, these behavioral impairments are responsive to therapeutic treatments, manipulations of the internal or external environment, or the level of arousal, since under certain conditions a recovery of function can occur in the absence of dopaminergic neurons. These two points provide additional support for a nonspecific role for the dopaminergic neurons originating in the ventral tegmental area. These neurons could have a permissive role in the functioning of the forebrain structures they innervate.