Insulin receptor substrate 2 is a negative regulator of memory formation

Insulin has been shown to impact on learning and memory in both humans and animals, but the downstream signaling mechanisms involved are poorly characterized. Insulin receptor substrate-2 (Irs2) is an adaptor protein that couples activation of insulin- and insulin-like growth factor-1 receptors to downstream signaling pathways. Here, we have deleted Irs2, either in the whole brain or selectively in the forebrain, using the nestin Cre- or D6 Cre-deleter mouse lines, respectively. We show that brain- and forebrain-specific Irs2 knockout mice have enhanced hippocampal spatial reference memory. Furthermore, NesCreIrs2KO mice have enhanced spatial working memory and contextual- and cued-fear memory. Deletion of Irs2 in the brain also increases PSD-95 expression and the density of dendritic spines in hippocampal area CA1, possibly reflecting an increase in the number of excitatory synapses per neuron in the hippocampus that can become activated during memory formation. This increase in activated excitatory synapses might underlie the improved hippocampal memory formation observed in NesCreIrs2KO mice. Overall, these results suggest that Irs2 acts as a negative regulator on memory formation by restricting dendritic spine generation.     

Response Interruption and Differential Reinforcement of Alternative Behavior for the Treatment of Pica

Pica displayed by two individuals with autism was decreased by a treatment involving differential reinforcement and response interruption that altered the chain of behavior involved in pica (i.e., picking up items and placing them in the mouth). The treatment involved establishing prompts to ‘clean‐up’ as a new discriminative stimulus (SD) for picking up items from the floor; and holding potential pica items was established as an SD for discarding those items in a trash receptacle, putting them away, or using them appropriately. After demonstrating the effectiveness of the treatment in an analog setting, the treatment package was systematically generalized to community settings. Copyright © 2011 John Wiley & Sons, Ltd.     

Differential acetylcholine release in the prefrontal cortex and hippocampus during pavlovian trace and delay conditioning

Pavlovian trace conditioning critically depends on the medial prefrontal cortex (mPFC) and hippocampus (HPC), whereas delay conditioning does not depend on these brain structures. Given that the cholinergic basal forebrain system modulates activity in both the mPFC and HPC, it was reasoned that the level of acetylcholine (ACh) release in these regions would show distinct profiles during testing in trace and delay conditioning paradigms. To test this assumption, microdialysis probes were implanted unilaterally into the mPFC and HPC of rats that were pre-trained in appetitive trace and delay conditioning paradigms using different conditional stimuli in the two tasks. On the day of microdialysis testing, dialysate samples were collected during a quiet baseline interval before trials were initiated, and again during performance in separate blocks of trace and delay conditioning trials in each animal. ACh levels were quantified using high-performance liquid chromatography and electrochemical detection techniques. Consistent with our hypothesis, results showed that ACh release in the mPFC was greater during trace conditioning than during delay conditioning. The level of ACh released during trace conditioning in the HPC was also greater than the levels observed during delay conditioning. While ACh efflux in both the mPFC and HPC selectively increased during trace conditioning, ACh levels in the mPFC during trace conditioning testing showed the greatest increases observed. These results demonstrate a dissociation in cholinergic activation of the mPFC and HPC during performance in trace but not delay appetitive conditioning, where this cholinergic activity may contribute to attentional mechanisms, adaptive response timing, or memory consolidation necessary for successful trace conditioning.     

A comparison of two flash-card methods for improving sight-word reading

Flash cards have been shown to be useful for teaching sight-word reading. To date, the most effective flash-card instruction method is incremental rehearsal (IR). This method involves the instructor interspersing unknown stimulus items into the presentation of known stimulus items. In this study, we compared IR to a modified IR procedure-strategic incremental rehearsal (SIR)-to determine whether the effects of IR might be improved by incorporating variables likely to increase word acquisition. These included increased opportunities to respond to unknown stimuli, using learner responding as a basis for changing instructional items, and systematic prompting methods. An A-B-A-B design was used to compare the effects of IR and SIR for increasing sight-word reading with 4 elementary school students. Results indicated that students read more words correctly with SIR than with IR. In addition, similar patterns of responding were seen at a 2-week follow-up.     

Increasing compliance with medical examination requests directed to children with autism: effects of a high-probability request procedure

The purpose of this study was to evaluate the effectiveness of a high-probability (high-p) request sequence as a means of increasing compliance with medical examination tasks. Participants were children who had been diagnosed with autism and who exhibited noncompliance during general medical examinations. The inclusion of the high-p request sequence effectively increased compliance with medical examination tasks. In addition, the procedure was efficient, could be implemented by parents and medical professionals, and did not involve aversive procedures.     

STEMing the tide: using ingroup experts to inoculate women's self-concept in science, technology, engineering, and mathematics (STEM)

Three studies tested a stereotype inoculation model, which proposed that contact with same-sex experts (advanced peers, professionals, professors) in academic environments involving science, technology, engineering, and mathematics (STEM) enhances women's self-concept in STEM, attitudes toward STEM, and motivation to pursue STEM careers. Two cross-sectional controlled experiments and 1 longitudinal naturalistic study in a calculus class revealed that exposure to female STEM experts promoted positive implicit attitudes and stronger implicit identification with STEM (Studies 1-3), greater self-efficacy in STEM (Study 3), and more effort on STEM tests (Study 1). Studies 2 and 3 suggested that the benefit of seeing same-sex experts is driven by greater subjective identification and connectedness with these individuals, which in turn predicts enhanced self-efficacy, domain identification, and commitment to pursue STEM careers. Importantly, women's own self-concept benefited from contact with female experts even though negative stereotypes about their gender and STEM remained active.     

The effects of behavioral activation therapy with inpatient geriatric psychiatry patients

This study examined the effects of Behavioral Activation (BA) treatment on depressive symptoms and quality of life among older adult patients in a geriatric psychiatry facility. There were 50 participants with mild to moderate cognitive impairment, each being 65 years of age or older. A 2 (between) × 3 (time of measurement) design was used in this study comparing control (treatment-as-usual) and experimental (BA) conditions at pre-, mid-, and posttreatment. BA consisted of eight 30- to 60-minute sessions across 4 weeks. Intent-to-treat analyses indicated a significant Group × Time interaction on depressive symptoms, with this effect remaining when only completer data were included. Further analyses indicated that this effect was due to significant change early in treatment in both the full and completer samples. There was no evidence of a significant effect on the quality-of-life measure. Cognitive status was not related to change in depressive symptoms, suggesting that BA may be useful across a range of older adults.     

The distinctiveness of hardiness, positive emotionality, and negative emotionality in National Guard soldiers

Exploratory and confirmatory factor analyses were used to investigate the distinctiveness of hardiness (using the Short Hardiness Scale; Bartone, 1995) from the broader personality traits of negative emotionality and positive emotionality (NEM and PEM; assessed with items from the MMPI-2 PSY-5 scales); in a sample of 981 Army National Guard soldiers. Exploratory factor analyses demonstrated that hardiness items loaded on a separate factor from PEM and NEM items, and confirmatory factor analysis suggested that hardiness is not simply a sub-facet of either PEM or NEM. However, subsequent regression analyses found that hardiness did not predict symptoms of PTSD or depression beyond the effects of PEM and NEM among combat exposed soldiers.     

Depression, impulsivity and health-related disability: A moderated mediation analysis

The goal of the current study is to examine how impulsivity affects the relationship between depression and health-related disability. Specifically, we examined impulsivity as a possible moderator of this relationship, as well as alcohol use, smoking, and binge eating as possible mediators. The study utilized the Collaborative Psychiatric Epidemiological Surveys (N = 20,013, mean age = 43.38, female = 57.3%). We conducted a series of moderated mediation analyses to test hypotheses. In all analyses, the relationship between depression and health-related disability was mediated by each maladaptive coping behavior, and the relationship between depression and the behavior was moderated by impulsivity. The study supports the utility of examining the individual difference mechanisms that might drive the relationship between depression and health-related disability.