Spatial offset of test field elements from surround elements affects the strength of motion aftereffects

Static movement aftereffects (MAEs) were measured after adaptation to vertical square-wave luminance gratings drifting horizontally within a central window in a surrounding stationary vertical grating. The relationship between the stationary test grating and the surround was manipulated by varying the alignment of the stationary stripes in the window and those in the surround, and the type of outline separating the window and the surround [no outline, black outline (invisible on black stripes), and red outline (visible throughout its length)]. Offsetting the stripes in the window significantly increased both the duration and ratings of the strength of MAEs. Manipulating the outline had no significant effect on either measure of MAE strength. In a second experiment, in which the stationary test fields alone were presented, participants judged how segregated the test field appeared from its surround. In contrast to the MAE measures, outline as well as offset contributed to judged segregation. In a third experiment, in which test-stripe offset was systematically manipulated, segregation ratings rose with offset. However, MAE strength was greater at medium than at either small or large (180 degrees phase shift) offsets. The effects of these manipulations on the MAE are interpreted in terms of a spatial mechanism which integrates motion signals along collinear contours of the test field and surround, and so causes a reduction of motion contrast at the edges of the test field.     

Neonatal odor-shock conditioning alters the neural network involved in odor fear learning at adulthood

Adult learning and memory functions are strongly dependent on neonatal experiences. We recently showed that neonatal odor-shock learning attenuates later life odor fear conditioning and amygdala activity. In the present work we investigated whether changes observed in adults can also be observed in other structures normally involved, namely olfactory cortical areas. For this, pups were trained daily from postnatal (PN) 8 to 12 in an odor-shock paradigm, and retrained at adulthood in the same task. (14)C 2-DG autoradiographic brain mapping was used to measure training-related activation in amygdala cortical nucleus (CoA), anterior (aPCx), and posterior (pPCx) piriform cortex. In addition, field potentials induced in the three sites in response to paired-pulse stimulation of the olfactory bulb were recorded in order to assess short-term inhibition and facilitation in these structures. Attenuated adult fear learning was accompanied by a deficit in 2-DG activation in CoA and pPCx. Moreover, electrophysiological recordings revealed that, in these sites, the level of inhibition was lower than in control animals. These data indicate that early life odor-shock learning produces changes throughout structures of the adult learning circuit that are independent, at least in part, from those involved in infant learning. Moreover, these enduring effects were influenced by the contingency of the infant experience since paired odor-shock produced greater disruption of adult learning and its supporting neural pathway than unpaired presentations. These results suggest that some enduring effects of early life experience are potentiated by contingency and extend beyond brain areas involved in infant learning.     

Emotional catharsis and aggression revisited: heart rate reduction following aggressive responding

The authors tested two components of the catharsis theory of aggression: physiological tension reduction and aggressive drive reduction. On the basis of work in the stress-aggression literature, they also examined the moderating effect of impersonal stress exposure on cathartic reductions in heart rate following aggressive responding. Participants were instructed to administer nonaggressive (correct button) or aggressive (shock button) responses to a frustrating confederate in a laboratory aggression paradigm, and half the participants were exposed to an impersonal stressor (aversive air blasts) during the procedure. Heart rate was recorded before and after the participants administered the aggressive or nonaggressive response. Analyses revealed that participants exhibited reductions in heart rate following aggressive but not nonaggressive responding, but this was the case only for those not exposed to the impersonal stressor. Heart rate reductions during the experimental blocks actually predicted the most intense aggression in a subsequent block of trials. The results are considered in light of different theories of aggression by J. E. Hokanson (1974) and L. Berkowitz (1990) and have implications for interventions with anger-prone individuals.     

Deterring malingered psychopathology: The effect of warning simulating malingerers

The utility of a warning to deter malingering on measures of personality and psychopathology was examined. Sixty‐seven first year psychology students were randomly assigned to one of three conditions: unwarned malingerers, warned malingerers, and controls. Participants in the two malingering groups were given a financial incentive to simulate believable psychological impairment. Warned malingerers received an additional warning that the tests could detect malingering and that detection would result in loss of course credit. Controls received standardized test instructions. It was hypothesized that the malingering incentive would be sufficient to induce malingering, but that a deterrence theory warning would have a subsequent deterrent effect. Between‐groups analyses indicated that the warning used in this study significantly altered test performance on the Personality Assessment Inventory (PAI) and revised Symptom Checklist 90 (SCL‐90‐R). Warned malingerers scored significantly lower (faked less) than unwarned malingerers on the majority of the psychopathology scales and frequently approximated control group performances. These results support the effectiveness of a warning to complement existing malingering detection methods. Copyright © 2009 John Wiley & Sons, Ltd.     

Self-perceived weight in adolescents: Over-estimation or under-estimation?

Prevalence of obesity has increased worldwide in the past 20 years, but it is not known whether this has resulted in increased numbers of young adults feeling overweight. This study evaluated weight self-perception in a large, multi-ethnic sample of 14-15 years old (n=4167) in London, UK as part of a longitudinal, school-based study of health behaviours. Weight perceptions were recorded on a simple scale from 'too thin' to 'too fat'. Results indicated that under-estimation was more common than over-estimation, with more than a quarter of overweight or obese adolescents unaware of their excess weight. Under-estimation was greatest among boys and ethnic minorities. It may be timely to reassess weight control advice given to adolescents.     

Are Gay Men in Worse Mental Health than Heterosexual Men? The Role of Age, Shame and Guilt, and Coming-Out

Previous studies reporting that gay individuals are in worse mental health than heterosexuals have typically employed young or mixed-age samples, ignoring the role of age. Mental health problems may show greater age-related improvement among gay than heterosexual men as indicated by the findings of the present study. In this study, the following indices of mental health are examined, and found to be comparable, among 86 heterosexual and 81 gay men aged 18–48: depression, suicidality, anger, anxiety, negative self-esteem, emotional instability, and lack of emotional responsiveness. Most indices show age-related effects among gay men, with less severe symptoms reported by older individuals. Among heterosexual men, effects of age are less widespread, although older men do report fewer symptoms of anger. Chronic shame and chronic guilt are related to mental health problems and a lessening in shame accounted, in part, for the age-related decline in depression among gay men. Different approaches to disclosing/concealing sexual identity are also linked with shame, guilt, and mental health among gay men.