Sleep deprivation impairs object recognition in mice

Many studies in animals and humans suggest that sleep facilitates learning, memory consolidation, and retrieval. Moreover, sleep deprivation (SD) incurred after learning, impaired memory in humans, mice, rats, and hamsters. We investigated the importance of sleep and its timing in an object recognition task in OF1 mice subjected to 6h SD either immediately after the acquisition phase (0-6 SD) or 6h later (7-12 SD), and in corresponding undisturbed controls. Motor activity was continuously recorded with infrared sensors. All groups explored two familiar, previously encountered objects to a similar extent, both at the end of the acquisition phase and 24h later during the test phase, indicating intact familiarity detection. During the test phase 0-6 SD mice failed to discriminate between the single novel and the two familiar objects. In contrast, the 7-12 SD group and the two control groups explored the novel object significantly longer than the two familiar objects. Plasma corticosterone levels determined after SD did not differ from time-matched undisturbed controls, but were significantly below the level measured after learning alone. ACTH did not differ between the groups. Therefore, it is unlikely that stress contributed to the memory impairment. We conclude that the loss of sleep and the activities the mice engaged in during the SD, impaired recognition memory retrieval, when they occurred immediately after acquisition. The delayed SD enabled memory consolidation during the 6h when the mice were allowed to sleep, and had no detrimental effect on memory. Neither SD schedule impaired object familiarity processing, suggesting that only specific cognitive abilities were sensitive to the intervention. Sleep may either actively promote memory formation, or alternatively, sleep may provide optimal conditions of non-interference for consolidation.     

Goal Motives, Well-Being, and Physical Health: Happiness and Self-Realization as Psychological Resources Under Challenge

An integrative model of goal motives, well-being, and physical health was tested within three studies. Study 1 demonstrated that pursuing autonomous goals was positively associated with both happiness and self-realization, whereas pursuing controlled goals was negatively associated with self-realization, but unrelated to happiness. Study 1 further revealed that self-realization was negatively associated with physical symptoms, whereas happiness was unrelated to the symptoms. Study 2 replicated the findings of Study 1 while showing that academic stress mediated the relationship between self-realization and physical symptoms. Finally, Study 3 replicated the findings of Studies 1 and 2 and additionally demonstrated that academic coping mediated the relationship between self-realization and academic stress. These findings are discussed in terms of their theoretical implications and directions for future research are proposed.

A randomised worksite comparison of acceptance and commitment therapy and stress inoculation training

In this comparative intervention study, 107 working individuals with above average levels of distress were randomly assigned to one of three conditions: acceptance and commitment therapy (ACT; n = 37); stress inoculation training (SIT; n = 37); or a waitlist control group (n = 33). The interventions were delivered to small groups in the workplace via two half-day training sessions. ACT and SIT were found to be equally effective in reducing psychological distress across a three month assessment period. Mediation analysis indicated that the beneficial impact of ACT on mental health resulted from an increase in psychological flexibility rather than from a change in dysfunctional cognitive content. Contrary to hypothesis, a reduction in dysfunctional cognitions did not mediate change in the SIT condition. Results suggest that the worksite may offer a useful, yet underutilised, arena for testing cognitive-behavioural theories of change.     

Comparative analysis of integrative self-knowledge, mindfulness, and private self-consciousness in predicting responses to stress in Iran

Previous research has established that awareness of self-experience is a stress resistance resource. The present study conducted an analysis of measures that record different aspects of self-awareness (private self-consciousness, mindfulness, and integrative self-knowledge) to explain this stress-resistance effect in a sample of Iranian university students (N = 186). These students responded to Mindfulness Attention Awareness, Private Self-Consciousness, Integrative Self-Knowledge, and Perceived Stress Scales just before the stress of a 20-day final examination period, and they then responded to Symptom Checklist and Vitality measures at four-day intervals during the final examinations. Prior to final examinations, the three self-awareness variables correlated positively with each other and negatively with perceived stress. Regression analyses of the data obtained during final examinations identified mindfulness to be a better operationalization of this stress-resistance resource than private self-consciousness. Specifically, mindfulness but not private self-consciousness was a positive predictor of vitality and a negative predictor of symptoms. Hierarchical regression analyses also demonstrated that mindfulness and integrative self-knowledge both explained resistance to physical symptoms, while integrative self-knowledge functioned as a protective factor toward one's vitality. These data confirm the positive impact that self-awareness has during stress and highlight the importance of considering both mindfulness and integrative self-knowledge in understanding stress-resistance processes.     

Les troubles des comportements alimentaires chez des étudiants de première année : une étude prospective multigroupes

There is increasing use of the phrase “campus eating symptoms” to describe regular binge eating (together with frequent exercise, and occasional reliance on vomiting or laxatives), concerns about body image, depressive symptoms, stress, and university adjustment problems among students. Incidence of eating disorders in the early grades of university is increasing, and the period from age 17–19 years (peak of bulimia) which corresponds to the beginning of study at university is critical. Given the stressful environment that is the 1st academic year, it is useful to consider eating disorders risk factors.

Method

Our study is longitudinal. At the beginning, the participants consisted of 1110 freshmen. Data regarding adjustment to university, gender, body image, BMI, transactional variables (perceived stress and coping) and eating disorders (EAT-26) were collected. At T2 (end of academic year), 556 students were recruited to reassess their eating behaviours. The aim of the study was to test gender invariance of a theoretical eating disorders model including all these variables and eating disorders measured a year apart from a mixed population integrating the university for the first times. This model assumes that these variables exert direct effects on eating disorders as measured in time one who in turn will affect the stability of these troubles a year later. Although very little research include boys in the study of eating disorders, the results of our multi-group analysis support the idea of the existence of sex differences in eating disorder predictors: the only common predictor of eating disorders among girls and boys was the use emotion-focused coping. Among boys, the best predictors of eating disorders were problem-focused coping, and seeking social support. Among girls, our results revealed that body mass index, body image, and academic adjustment and stress were the predictors of eating disorders. Finally, we found a temporal stability of eating disorders. This study showed that personal and contextual aspects have a direct impact on students’ eating behaviour. However, among boys, neither body image nor perceived stress affect the eating behaviour but how they cope with stress. The gender gap in the explanation of eating disorders suggest to not exclude the male population in this type of study and to treat the data separately.     

Stress at encoding,context at retrieval,and children’s narrative content

Research concerning the relations between stress and children’s memory has been primarily correlational and focused on memory volume and accuracy. In the current study, we experimentally manipulated 7- and 8-year-olds’ and 12- to 14-year-olds’ experienced stress during a to-be-remembered event to examine the effects of stress on the content of their memory. We further manipulated the degree of interviewer support at retrieval to determine whether it moderated the effects of stress at encoding on memory. Children’s age, gender, stress at encoding, and interviewer support all influenced the type of information included in their narrative reports. Most notably, across ages, children who experienced a more stressful event but were questioned in a supportive manner provided the largest ratio of terms representing internal states such as those about cognitions and emotions. Results suggest that how children process past events may be influenced by both the nature of the event itself and the context within which it is recalled.     

The distressed (Type D) and Five-Factor Models of personality in young,healthy adults and their association with emotional inhibition and distress

The distressed (Type D) personality (the combination of negative affectivity and social inhibition traits) has been associated with adverse health outcomes. This study investigated the validity of the Type D construct against the Five-Factor Model (FFM) of personality, and its association with emotional control and distress. In total 498 university students (mean age 28.9 ± 8.4 years) completed the Type D scale (DS14), and measurements for the FFM of personality, emotional control, anxiety, depression and stress. The construct validity of the Icelandic DS14 was confirmed. The Type D components negative affectivity and social inhibition were strongly associated with neuroticism and extraversion of the FFM (r = 0.82 and r = −0.67, respectively). Negative affectivity also correlated with rehearsal/rumination (r = 0.58) and social inhibition with emotional inhibition (r = 0.54), indicative of emotional control. Type D personality (40% of sample) was associated with higher levels of anxiety, depression and stress. The Type D personality components were associated with the FFM of personality, emotional control and emotional distress. Importantly, social and emotional inhibition were closely related, providing novel information about the presence of emotional inhibition within the social inhibition trait.     

Overgeneral autobiographical memory and chronic interpersonal stress as predictors of the course of depression in adolescents

This study investigated whether overgeneral autobiographical memory (OGM) predicts the course of depression in adolescents. As part of a larger longitudinal study of risk for emotional disorders, 55 adolescents with a past history of major depressive disorder or minor depressive disorder completed the Autobiographical Memory Test. Fewer specific memories predicted the subsequent onset of a major depressive episode (MDE) over a 16-month follow-up period, even when covarying baseline depressive symptoms. This main effect was qualified by an interaction between specific memories and chronic interpersonal stress: Fewer specific memories predicted greater risk of MDE onset over follow-up at high (but not low) levels of chronic interpersonal stress. Thus, our findings suggest that OGM, in interaction with chronic interpersonal stress, predicts the course of depression among adolescents, and highlight the importance of measuring interpersonal stress in OGM research.     

The stress-eating paradox: Multiple daily measurements in adult males and females

Abstract

The stress-eating relationship was examined in a prospective study of 158 subjects who completed daily records of stress and eating for 84 days, yielding 16.188 person days of observation. Using both within-subjects and between-subjects analyses, individuals were much more likely to eat less than usual than to eat more than usual in response to stressful daily problems. The likelihood of eating more did not change as severity of stress increased, but the likelihood of eating less increased substantially. There were also clear gender differences. Males had a slight tendency to eat less than to eat more across all levels of stress, except at the highest level, where eating less occurred much more frequently. In females, the tendency to eat less as opposed to eating more emerged at middle levels of stress; at the highest level of stress, females were more than three times more likely to eat less than to eat more. Individual subjects were highly consistent over levels of stress in the direction of eating; 82% of the subjects were consistent in eating more or less over the majority of their stressful periods. These results show a clear effect of stress on eating, with eating less being the predominant response.     

Cortisol reactivity in the laboratory predicts ineffectual attentional control in daily life

Objective: The objective was to examine an executive control difficulty perspective on individual differences in cortisol reactivity using a daily protocol.

Design: Fifty participants competed a laboratory stressor task and individualdifferences in cortisol reactivity were quantified.

Main outcome measures: Daily attentional control, conflicting thoughts, error reactivity, worry and mindfulness were assessed.

Results: The findings support the idea that as cortisol responses to stress get larger (as an individual difference), attentional control ceases to function as it should in terms of variables that should predict (mindfulness) and follow from (e.g. worry) it.

Conclusion: The findings support the idea that individual differences in cortisol reactivity can be conceptualised in terms of ineffectual attentional control.