Fighting experiences and natural killer cell activity in male laboratory mice

There is currently much interest in the potential impact of psychological factors on immune responses. An attempt was made to assess the effects of dominant/subordinate polarity in male mice on the cytotoxic activities of their natural-killer (NK) cells. On the basis of repeated agonistic encounters, categories of subordinate and dominat animals were selected. These animals were compared with manipulated controls (introduced to a novel test cage without an opponent on each occasion) and undisturbed controls (who remained in isolation without manipulation). In terms of NK activity, immunosuppression was observed in both dominant and subordinate categories when compared to undisturbed controls. There were, however, no differences between the fighting exposed subjects and the manipulated controls, suggesting that stress accounts for any changes. © 1994 Wiley-Liss, Inc.     

Hungry people prefer larger bodies and objects: The importance of testing boundary effects

Several lab-based studies have indicated that when people are hungry, they judge larger women's bodies as more attractive, compared to when they are satiated. These satiety-dependent judgements are assumed to provide explanatory power when it comes to the noted cross-cultural differences in attitudes towards women's adiposity, whereby people who live in regions that are under greater nutritional stress tend to have more favourable attitudes towards bigger bodies. However, it is premature to assume that women's bodies are the proper or actual domain of the satiety-dependent judgement shifts found within research study testing contexts until stimuli other than female bodies have also been tested: The research programme falls into the trap of confirmation bias unless we also seek out disconfirmatory evidence and test the boundaries of the effects of hunger. Accordingly, we collected attractiveness judgements of female and male bodies manipulated to vary in size by varying level of adiposity, and objects manipulated to vary in size, from 186 participants who also reported their current hunger level. We found that larger sizes of stimuli in general, and women's bodies in particular, especially when judged by women, were judged as more attractive by the hungrier participants. We discuss these patterns in the context of the Insurance Hypothesis, the Environmental Security Hypothesis, and the impact of hunger on acquisition.     

Paths from core belief disruption to post-traumatic stress symptoms and post-traumatic growth among Korean undergraduates: The mediating role of rumination

The post-traumatic growth (PTG) model proposes that cognitive processing is a key mechanism that leads to growth in the aftermath of traumatic events. Building upon the PTG model, the present study examined the paths from the disruption of core beliefs to post-traumatic stress symptoms (PTSS) and PTG via intrusive and deliberate rumination. The sample includes 370 Korean undergraduate students who reported at least one highly stressful experience in their lifetime. Structural equation modeling demonstrated that disruption of core beliefs predicted PTG both directly and indirectly through multiple pathways: via deliberate rumination, intrusive rumination, and the path from intrusive to deliberate rumination. The disruption of core beliefs positively predicted PTSS only through intrusive rumination. No bivariate relationship was found between PTSS and PTG. These findings support the different roles of intrusive rumination and deliberate rumination in mediating the paths from disruption of core beliefs to PTSS and PTG. Implications and limitations of this study were discussed.     

Regression II. Development through regression

As shown in our previous paper (‘Regression I. Experimental approaches to regression’, JAP, 65, 2, 345-65), the common mechanism of regression can be described as reversible dedifferentiation, which is understood as a relative increase of the proportion of low-differentiated (older) systems in actualized experience. Experimental data show that regression following disease (chronic tension headache) is followed by adaptation and an increase in system differentiation in that experience domain which contains systems responsible for that adaptation. The results of mathematical modelling support the idea that reversible dedifferentiation can be one of the mechanisms for increasing the effectiveness of adaptation through learning. Reversible dedifferentiation, which is phenomenologically described as regression, is a general mechanism for restructuring the organism-environment interactions in situations where behaviours that were effective in the past become ineffective. Reversible dedifferentiation has evolved as a component of adaptation when new behaviours are formed and large-scale modifications in the existing behaviours are required in the face of changes in the external and/or internal environment. Thus, the authors believe that this article provides evidence for Jung’s view that regression is not only a ‘return’ to past forms of thinking, affects and behaviour, but that regressive processes provide a significant impetus for psychological growth and development.     

Triggering Creative Self-Efficacy to Increase Employee Innovation Behavior in the Hospitality Workplace

This study investigated how creative personality, psychological empowerment, and job stress affect creative self-efficacy and innovative behavior in hospitality employees. A hypothesized moderating role of knowledge-sharing role in the relationship between creative self-efficacy and innovative behavior was also tested. Three hundred and thirty-nine employees and 89 supervisors employed by International Tourist Hotels in Taiwan participated in the study. A structural equation modeling analysis indicated that creative self-efficacy significantly mediates the effects of creative personality and psychological empowerment on innovative behavior in the hospitality industry. The positive effect of creative self-efficacy on innovative behavior was larger in high knowledge-sharing work environments than in low knowledge-sharing work environments. Theoretical and practical implications are further discussed.     

Pregrouping aggression and defense scores influences alcohol consumption for dominant and subordinate rats in visible burrow systems

Five male/two female rat colonies were established in visible burrow systems, with males selected for pregrouping attack scores and also evaluated in open field and cat odor tests. Dominant-subordinate pregrouping attack differences suggested that the males becoming dominant are those showing more persistent and higher level attack. For six colonies showing dominant-subordinate behavioral differences, pregrouping defense tests failed to predict subordinate status. However, pregrouping defense scores were reliably correlated with subordinate pre-postgrouping change scores for voluntary ethanol consumption. Subordinates showed higher ranked ethanol consumption than dominants, but these groups were not different on pregrouping ethanol consumption. Subordinate postgrouping ethanol consumption was positively correlated with pregrouping attack toward an adult intruder, consonant with previous findings that highly aggressive subordinates are the targets of more intense attack by dominants. These results provide further support for a view that subordination stress increases voluntary ethanol consumption in male rats and suggest some additional individual differences factors that may be involved in increased ethanol consumption for male subordinates. © 1992 Wiley-Liss, Inc.     

Effect of Acute Psychological Stress on Motion-in-Depth Perception: An Event-Related Potential Study

The present study explored the intrinsic event-related potential (ERP) features of the effects of acute psychological stress on the processing of motion-in-depth perception using a dual-task paradigm. After a mental arithmetic task was used to induce acute psychological stress, a collision task was used to evaluate motion-in-depth perception. The error value and average amplitude of late slow waves (SW) were significantly larger for the earlier colliding spheres’ than for the later colliding spheres. The P1 peak latency in the left occipital region was significantly shorter than that of the right occipital region in the motion-in-depth perception task. Compared to the control condition, the estimated value of residual time-to-collision and error value were significantly reduced, and the N1 peak amplitude and the SW averaged amplitude were significantly increased in the stress condition. Longer motion-in-depth time improved discrimination accuracy and decreased the investment of cognitive resources. Acute psychological stress increased behavioral performance and enhanced attention resources on the motion-in-depth perception task together with greater investment of cognitive resources.     

Hair sampling for cortisol analysis with mother-toddler dyads living in low-income homes

BackgroundA first step to advance stress science research in young children is understanding the relationship between chronic stress in a mother and chronic stress in her child. One non-invasive measure of chronic stress is hair cortisol. However, little is known about strategies for hair sampling in mother-toddler dyads living in low-income homes in the U.S. To address prior limitations, the purpose of this study was to understand the feasibility of sampling hair for cortisol analysis in mother-toddler dyads living in low-income homes in the U.S. We examined feasibility related to participation, eligibility, and gathering an adequate hair sample weight.MethodsWe approached 142 low-income, racially diverse, urban-dwelling mothers who were participating in an ongoing longitudinal birth cohort study for informed consent to cut approximately 150 hairs from the posterior vertex of their scalp and their toddlers’ (20–24 months) scalp. We demonstrated the process of sampling hair with a hairstyling doll during home visits to the mother and toddler using rounded-end thinning shears.ResultsOverall, 94 of 142 mother-toddler dyads (66 %) participated in hair sampling. The most common reason for participation refusal was related to hairstyle. All but three hair samples were of adequate weight for cortisol extraction.DiscussionThe findings from this study can help researchers address sampling feasibility concerns in hair for cortisol analysis research in mother-toddler dyads living in low-income homes in the U.S.     

急性应激损害对威胁刺激的注意解除

急性应激会增强个体对威胁刺激的注意偏向, 但急性应激是增强了对威胁刺激的注意定向还是损害了对威胁刺激的注意解除还不清楚。本研究采用社会评估冷压任务和点探测任务, 结合事件相关电位技术, 考察急性应激对威胁刺激注意偏向影响的认知机制。在进行社会评估冷压任务后, 应激组个体的状态焦虑和皮质醇浓度显著升高。在注意偏向中, 应激组对威胁刺激的注意解除比控制组更慢, 应激组和控制组在对威胁刺激的注意定向上无显著差异。ERP结果上, 威胁刺激诱发应激组比控制组产生了更负的SPCN, 在N2pc上没有显著差异。应激组和控制组皮质醇增量的差异和N2pc、SPCN的组间差异均有显著正相关。这些结果说明, 急性应激增强对威胁刺激的注意偏向是因为其损害个体对威胁刺激的注意解除, 这可能是因为急性应激损害了与注意解除相关的额-顶网络的功能所致。     

Antecedents of fathers’ perception of child behavior at child age 12 months

This study investigates whether fathers’ adverse childhood experiences (ACE) and attachment style reported during pregnancy predict fathers’ perception of child behavior assessed 12 months postpartum, expressed by the Parenting Stress Index (PSI), Child Domain. Prospective fathers (N = 835) were recruited to “The Little in Norway (LiN) study” (Moe & Smith) at nine well-baby clinics in Norway, with data collection composed of five time points during pregnancy and two time points postpartum (6 and 12 months). The main analyses included linear regression, path-analysis modeling, and intraclass correlation based on mixed effects modeling. First, linear regression analyses showed that neither fathers’ ACE nor attachment style significantly predicted perceived child behavior postpartum directly. Furthermore, path analyses showed that ACE and less secure attachment style (especially avoidant attachment) measured early in pregnancy strongly predicted negatively perceived child behavior, mediated by fathers’ mental health symptoms during pregnancy and partner disharmony postpartum. Second, intraclass correlation analyses showed that fathers’ perceived child behavior showed substantial stability between 6 and 12 months postpartum. Family interventions beginning in pregnancy may be most beneficial given that fathers’ early experiences and perceptions of attachment in pregnancy were associated with later partner disharmony and stress.