The neural correlates of alcohol-related aggression

Alcohol intoxication is implicated in approximately half of all violent crimes. Over the past several decades, numerous theories have been proposed to account for the influence of alcohol on aggression. Nearly all of these theories imply that altered functioning in the prefrontal cortex is a proximal cause. In the present functional magnetic resonance imaging (fMRI) experiment, 50 healthy young men consumed either a low dose of alcohol or a placebo and completed an aggression paradigm against provocative and nonprovocative opponents. Provocation did not affect neural responses. However, relative to sober participants, during acts of aggression, intoxicated participants showed decreased activity in the prefrontal cortex, caudate, and ventral striatum, but heightened activation in the hippocampus. Among intoxicated participants, but not among sober participants, aggressive behavior was positively correlated with activation in the medial and dorsolateral prefrontal cortex. These results support theories that posit a role for prefrontal cortical dysfunction as an important factor in intoxicated aggression.     

Does the use of natural stimuli facilitate amodal completion in pigeons?

Three experiments were carried out to investigate whether amodal completion in pigeons can be facilitated by the use of colour photographs instead of highly artificial stimuli such as geometrical shapes. Ten pigeons were trained in a go/no-go procedure to discriminate between photographs of complete and of incomplete pigeon figures. In the subsequent test, the birds classified pictures of partly occluded pigeons as though they were complete (experiment 1). However, we found evidence that classification was based on spurious stimulus features that paralleled the intended class rule of figural completeness versus incompleteness. In particular, classification was shown to be guided by white background gaps that separated the parts of the fragmented pigeon figures (experiment 2), as well as by cues related to overall Gestalt (experiment 3). In summary, the present results indicate that the use of more natural stimuli such as photographs instead of geometrical shapes is insufficient for providing amodal completion in pigeons. It is suggested that a combination of various cues, including, eg, 3-D information and common motion in addition to surface and contour properties, may be required to induce a perceptual bias favouring visual completion of occluded portions.     

Mood and memory for tightly organized social information

The frequently cited finding that mood-congruent information can be better recalled than mood-incongruent information is tested using categorically organized stimulus material which imposes a systematic structure on the recall process. A target person was described with respect to six categories of social behaviour, with predominantly desirable behaviours in some categories and predominantly undesirable behaviours in others. Participants were induced either an elated mood state or a neutral state using Velten's procedure. Instructions (impression formation versus memory) were also manipulated. Although the mood manipulation apparently worked and did influence the impression judgments of the target person, it did not selectively facilitate the recall of mood-congruent material, neither at the level of specific items nor at the categorical level. However, when only deviating behaviours are considered which do not fit the structural constraints, mood-congruent information is indeed better recalled. To interpret these results, it is argued that the manifestation of mood effects depends on the restrictions of different tasks or response modes. Three other findings were obtained: Superior recall of redundant, structurally consistent information compared with deviating information; an advantage of positive over negative information which is confined to the impression formation condition; and, surprisingly, an incongruency effect for the encoding mood which may reflect the deeper processing of incongruent material.     

Generalisierte Angststörung

The core features of generalized anxiety disorder (GAD) are excessive worry about various topics which are perceived as uncontrollable and mostly last for at least 6 months. Worrying is accompanied by a number of symptoms (e.g. muscle tension and irritability). Various etiological models suggest that avoidance of internal processes (e.g. cognitive, emotional, and physical) by worrying is central to the development and maintenance of GAD. Empirically well supported cognitive-behavioral interventions are worry exposure, applied relaxation, treating metacognitions, intolerance of uncertainty and negative problem orientation. Initial studies indicate the efficacy of mindfulness and acceptance-based approaches as well as psychodynamic approaches to treat GAD. The present article reports central diagnostic procedures, important differential diagnoses and illustrates actual (psycho) therapeutic treatment options.     

Lactation and stress: protective effects of breast-feeding in humans

Whilst most research on breast-feeding has been designed to assess its importance for infant health or to find a human nutrient replacement for infant formula, the effects of breast-feeding on maternal health have received little scientific attention. In several animal studies lactation has been shown to be associated with a marked blunting of physiological and behavioral responses to physical and psychological stress. However, the literature on the effects of lactation on stress in humans remains limited. This review focuses primarily on recent findings on the effects of breast-feeding on neuroendocrine and behavioral responses to acute stress exposure in lactating women. The available data suggest that breast-feeding suppresses the hypothalamic-pituitary-adrenal (HPA) axis response to physical and psychosocial stress. However, lactation in women, in contrast to lactating rats, does not seem to result in a general restraint of the endocrine stress response during the whole period of lactation. Recent data strongly suggest that the blunted HPA axis response to stress in women seems to be counterbalanced if the acute stressor, at least when of a psychosocial nature, occurs later than 1 h after suckling. Further elucidation of the underlying psychobiological mechanisms involved in suppressed stress responses during lactation will no doubt lead to new insights into improved health sequelae of breast-feeding in women and to a better understanding of the psychobiology of human stress protection in general.     

Now I see it but you don't: 14-month-olds can represent another person's visual perspective

Twelve- and 14-month-old infants' ability to represent another person's visual perspective (Level-1 visual perspective taking) was studied in a looking-time paradigm. Fourteen-month-olds looked longer at a person reaching for and grasping a new object when the old goal-object was visible than when it was invisible to the person (but visible to the infant). These findings are consistent with the interpretation that infants 'rationalized' the person's reach for a new object when the old goal-object was out of sight. Twelve-month-olds did not distinguish between test conditions. The present findings are consistent with recent research on infants' developing understanding of seeing.