Timing is essential for rapid effects of corticosterone on synaptic potentiation in the mouse hippocampus

Stress facilitates memory formation, but only when the stressor is closely linked to the learning context. These effects are, at least in part, mediated by corticosteroid hormones. Here we demonstrate that corticosterone rapidly facilitates synaptic potentiation in the mouse hippocampal CA1 area when high levels of the hormone and high-frequency stimulation coincide in time, but not when corticosterone is given either before or after repetitive stimulation. This effect could not be blocked by antagonists of the mineralocorticoid receptor and glucocorticoid receptor (spironolactone and RU 38486, respectively). These data provide a biological substrate for the important behavioral observation that stress and corticosteroid hormones can facilitate learning and memory processes.     

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.     

Do humans and baboons use the same information when categorizing human and baboon faces?

What information is used for sorting pictures of complex stimuli into categories? We applied a reverse correlation method to reveal the visual features mediating categorization in humans and baboons. Two baboons and 6 humans were trained to sort, by species, pictures of human and baboon faces on which random visual noise was superimposed. On ambiguous probe trials, a human-baboon morph was presented, eliciting "human" responses on some trials and "baboon" responses on others. The difference between the noise patterns that induced the two responses made explicit the information mediating the classification. Unlike the humans, the baboons based their categorization on information that closely matched that used by a theoretical observer responding solely on the basis of the pixel similarities between the probe and training images. We show that the classification-image technique and principal components analysis provide a method to make explicit the differences in the information mediating categorization in humans and animals.     

Outcome From a Randomized Controlled Trial of Group Therapy for Binge Eating Disorder: Comparing Dialectical Behavior Therapy Adapted for Binge Eating to an Active Comparison Group Therapy

Dialectical Behavior Therapy for Binge Eating Disorder (DBT-BED) aims to reduce binge eating by improving adaptive emotion-regulation skills. Preliminary findings have been promising but have only compared DBT-BED to a wait-list. To control for the hypothesized specific effects of DBT-BED, the present study compared DBT-BED to an active comparison group therapy (ACGT). Men and women (n = 101) meeting DSM-IV BED research criteria were randomly assigned to 20 group sessions of DBT-BED (n = 50) or ACGT (n = 51). DBT-BED had a significantly lower dropout rate (4%) than ACGT (33.3%). Linear Mixed Models revealed that posttreatment binge abstinence and reductions in binge frequency were achieved more quickly for DBT-BED than for ACGT (posttreatment abstinence rate = 64% for DBT-BED vs. 36% for ACGT) though differences did not persist over the 3-, 6-, and 12-month follow-up assessments (e.g., 12-month follow-up abstinence rate = 64% for DBT-BED vs. 56% for ACGT). Secondary outcome measures revealed no sustained impact on emotion regulation. Although both DBT-BED and ACGT reduced binge eating, DBT-BED showed significantly fewer dropouts and greater initial efficacy (e.g., at posttreatment) than ACGT. The lack of differential findings over follow-up suggests that the hypothesized specific effects of DBT-BED do not show long-term impact beyond those attributable to nonspecific common therapeutic factors.     

Symbolic and nonsymbolic number comparison in children with and without dyscalculia

Developmental dyscalculia (DD) is a pervasive difficulty affecting number processing and arithmetic. It is encountered in around 6% of school-aged children. While previous studies have mainly focused on general cognitive functions, the present paper aims to further investigate the hypothesis of a specific numerical deficit in dyscalculia. The performance of 10- and 11-year-old children with DD characterised by a weakness in arithmetic facts retrieval and age-matched control children was compared on various number comparison tasks. Participants were asked to compare a quantity presented in either a symbolic (Arabic numerals, number words, canonical dots patterns) or a nonsymbolic format (noncanonical dots patterns, and random sticks patterns) to the reference quantity 5. DD children showed a greater numerical distance effect than control children, irrespective of the number format. This favours a deficit in the specialised cognitive system underlying the processing of number magnitude in children with DD. Results are discussed in terms of access and representation deficit hypotheses.     

Development and Initial Validation of an Implicit Measure of Religiousness‐Spirituality

An implicit measure of religiousness‐spirituality (RS) was constructed and used in two studies. In Study 1, undergraduates completed a Religiousness‐Spirituality Implicit Association Test (RS‐IAT) and several self‐report measures of RS and related constructs (e.g., religious fundamentalism, authoritarianism). Informants rated the participants’ RS. The RS‐IAT was internally consistent. Implicit RS correlated positively with self‐reported RS, spiritual transcendence, spiritual experiences, religious fundamentalism, and intrinsic religiousness. Informant ratings correlated positively with participants’ self‐reported religiousness but not implicit RS. In Study 2, implicit RS accounted for unique variability in self‐reported attitudes toward gay men and lesbian women when controlling for self‐reported religiousness and right‐wing authoritarianism. These findings demonstrate that an implicit measure of trait RS explains some variability in attitudes that self‐report measures do not. An implicit measure of RS could advance the scientific study of religion beyond what is known from self‐report measures.     

More than just skin deep? Personality information influences men's ratings of the attractiveness of women's body sizes

This study examined the influence of personality information on perceptions of the physical attractiveness of a range of female body sizes. A sample of 2,157 male university students were randomly assigned to one of 10 groups in which they received personality information about women they were rating, or a control group in which they received no personality information. Controlling for participants' age and body mass index, results showed no significant between-group differences in the body size that participants found most attractive. However, participants provided with positive personality information perceived a wider range of body sizes as physically attractive compared with the control group, whereas participants provided with negative personality information perceived a narrower range of body sizes as attractive. Correlations showed that participants' own Extraversion was associated with their body size ratings. These results suggest that non-physical cues have an influence on the perception of physical beauty.