Prolactin and paternal care: comparison of three species of monogamous new world monkeys (Callicebus cupreus,Callithrix jacchus,and Callimico goeldii)

The authors explored whether prolactin is associated with paternal care in 3 monkey species: titi monkey (Callicebus cupreus), common marmoset (Callithrix jacchus), and Goeldi's monkey (Callimico goeldii). They compared prolactin levels in fathers before and after infant birth as well as between fathers and nonfathers. C. cupreus fathers carry infants almost exclusively, have higher prolactin levels than nonfathers, but show no prolactin increase after infant birth. C. goeldii fathers carry infants only after 3 weeks, show an increase in prolactin levels during the precarrying period, but do not have higher levels than nonfathers. C jacchus fathers are the primary carriers, have higher prolactin levels than nonfathers, and show a trend for a prolactin increase after the birth of infants. In conclusion, species differences in the patterns of prolactin secretion were evident and reflect the different paternal roles.     

New methodology applied to bonnet macaques (Macaca radiata) to address some contradictory evidence on manual asymmetries in Old World monkeys

Seven bonnet macaques (Macaca radiata) with strong hand preferences in performing a computer-generated joystick task that required directing a cursor to contact a small stationary target on a monitor were given comparable experience with each hand on the task over a 5-week period. Hand use was randomly restricted to either only the left or only the right hand across trials by automatically inputting into a computer the unique identification numbers of microchips implanted in the forearms of each macaque. Subsequent presentation of a novel task requiring maintenance of contact between a cursor and a moving target revealed no performance difference between preferred and nonpreferred hands or between left and right hands on the basis of number of errors or time to complete the task. The findings suggest that the strong hand preference for these tasks does not derive from a performance advantage for the preferred hand.     

GENDER'S ROLE IN RESPONSES TO INFERTILITY

Infertility is a major life stressor that affects approximately 10% of U.S. married couples. Infertile women and men have reported experiencing depression, helplessness, and marital strain. Given U.S. society's emphasis on women's role as mothers, it has been suggested that women's lives are more disrupted by infertility than those of men. This hypothesis was supported in a survey of 185 infertile couples and 90 presumed fertile couples. Infertile wives, as compared to their husbands, perceived their fertility problem as more stressful, felt more responsible for and in control of their infertility, and engaged in more problem-focused coping. Infertile husbands experienced more home life stress and lower home life performance than did their wives. These differences were not found for presumed fertile couples. Both infertile and presumed fertile wives experienced more depression, more sexual dissatisfaction, and lower self-esteem than did their husbands. Theoretical and counseling implications of these findings are discussed.     

The effects of post-encoding stress on recognition memory: examining the impact of skydiving in young men and women

Prior studies have indicated that post-encoding stress can protect memories from the effects of forgetting, and this has been taken as evidence that stress facilitates memory consolidation. However, it is not known whether stress acts by directly influencing the strength of the underlying memories or whether it influences the generation process that plays a critical role in tests such as free recall. To address this issue, we examined the effects of stress produced by skydiving on recognition memory for negative and neutral pictures. Relative to a non-stress control condition, post-encoding stress in males was found to increase recognition memory for neutral pictures. However, stress was not found to improve recognition for emotional pictures, nor was it found to influence recognition memory in female participants. Additional analysis of recognition performance suggested that stress increased familiarity-based recognition rather than recollection. This study indicates that stress can improve familiarity-based recognition, thus showing that stress directly increases the strength of the underlying memories.     

Imitation from 12 to 24 months in autism and typical development: a longitudinal Rasch analysis

The development of imitation during the second year of life plays an important role in domains of sociocognitive development such as language and social learning. Deficits in imitation ability in persons with autism spectrum disorder (ASD) from toddlerhood into adulthood have also been repeatedly documented, raising the possibility that early disruptions in imitation contribute to the onset of ASD and the deficits in language and social interaction that define the disorder. This study prospectively examined the development of imitation between 12 and 24 months of age in 154 infants at familial risk for ASD and 78 typically developing infants who were all later assessed at 36 months for ASD or other developmental delays. The study established a developmental measure of imitation ability and examined group differences over time, using an analytic Rasch measurement model. Results revealed a unidimensional latent construct of imitation and verified a reliable sequence of imitation skills that was invariant over time for all outcome groups. Results also showed that all groups displayed similar significant linear increases in imitation ability between 12 and 24 months and that these increases were related to individual growth in both expressive language and ratings of social engagement but not in fine motor development. The group of children who developed ASD by age 3 years exhibited delayed imitation development compared with the low-risk typical outcome group across all time-points, but were indistinguishable from other high-risk infants who showed other cognitive delays not related to ASD.     

On the Interaction of Prior Knowledge and Stimulus Structure in Category Learning

Contemporary theories of categorization propose that concepts are coherent in virtue of being embedded in a network of theories about the world. Those theories function to pick out some of the many possible features of a set of objects as most salient for purposes of classification, a process that is complex and still poorly understood (Murphy & Medin, 1985). Part of what makes this account incomplete is a lack of information as to (1) what makes a feature salient on a given occasion and (2) how feature salience interacts with category structure to determine the course of learning. We report on the results of three studies of category learning using complex schematic drawings to show that (1) the contrast set defined by one's initial encounters with category exemplars can be a source of individual differences in feature salience assignments; (2) such effects are short-lived in the face of clear evidence about actual feature diagnosticity; and (3) more robust prior hypotheses interact with category structure to either enhance learning or impede it. The enhancement occurs when the hypothesis emphasizes category-relevant features, even if the hypothesis is in fact incorrect. A hypothesis that assigns high salience to irrelevant features impedes learning. Learning does occur as feedback concerning category structure leads to enhanced salience for relevant features. Salience of irrelevant features remains high, however, suggesting that such learning as occurs involves augmentation and not total revision of the (incorrect) prior hypothesis.     

Inequalities of power and sexual problems

The proposition that sexual problems can emerge as a response to structural inequalities of power is explored by reference to a case which forms part of our current clinical work and research in this area. It is suggested that inequalities of power between heterosexual partners and societal 'discourses' which support the use of sexuality, predominantly by women, as an influence strategy, can serve to promote the development and maintenance of sexual symptoms as forms of covert power struggles. An integration is attempted of systemic and feminist theories with some practical suggestions for therapists working with couples with sexual problems.     

Development of a short form Social Interaction Anxiety (SIAS) and Social Phobia Scale (SPS) using nonparametric item response theory: the SIAS-6 and the SPS-6

Shortened forms of the Social Interaction Anxiety Scale (SIAS) and the Social Phobia Scale (SPS) were developed using nonparametric item response theory methods. Using data from socially phobic participants enrolled in 5 treatment trials (N = 456), 2 six-item scales (the SIAS-6 and the SPS-6) were developed. The validity of the scores on the SIAS-6 and the SPS-6 was then tested using traditional methods for their convergent validity in an independent clinical sample and a student sample, as well as for their sensitivity to change and diagnostic sensitivity in the clinical sample. The scores on the SIAS-6 and the SPS-6 correlated as well as the scores on the original SIAS and SPS, with scores on measures of related constructs, discriminated well between those with and without a diagnosis of social phobia, providing cutoffs for diagnosis and were as sensitive to measuring change associated with treatment as were the SIAS and SPS. Together, the SIAS-6 and the SPS-6 appear to be an efficient method of measuring symptoms of social phobia and provide a brief screening tool.     

Eliciting and maintaining ruminative thought: the role of social-evaluative threat

This study tested whether a performance stressor characterized by social-evaluative threat (SET) elicits more rumination than a stressor without this explicit evaluative component and whether this difference persists minutes, hours, and days later. The mediating role of shame-related cognition and emotion (SRCE) was also examined. During a laboratory visit, 144 undergraduates (50% female) were randomly assigned to complete a speech stressor in a social-evaluative threat condition (SET; n = 86), in which an audience was present, or a nonexplicit social-evaluative threat condition (ne-SET; n = 58), in which they were alone in a room. Participants completed measures of stressor-related rumination 10 and 40 min posttask, later that night, and upon returning to the laboratory 3-5 days later. SRCE and other emotions experienced during the stressor (fear, anger, and sadness) were assessed immediately posttask. As hypothesized, the SET speech stressor elicited more rumination than the ne-SET speech stressor, and these differences persisted for 3-5 days. SRCE-but not other specific negative emotions or general emotional arousal-mediated the effect of stressor context on rumination. Stressors characterized by SET may be likely candidates for eliciting and maintaining ruminative thought immediately and also days later, potentially by eliciting shame-related emotions and cognitions.