Intrahippocampal insulin improves memory in a passive-avoidance task in male wistar rats

The main impacts of insulin favor the peripheral organs. Although it functions as a neuropeptide, insulin possesses also some central effects. The aim of this study was to determine the effect of intrahippocampal infusion of insulin on passive avoidance learning in healthy male rats. Thirty male wistar rats were divided into three groups (n=10 each). The experimental group had posttraining insulin infusion into the CA1 region of dorsal hippocampus, after which they were compared with sham (saline) and control (intact) groups. Insulin treated animals had greater latency to enter the dark compartment in compare with saline treated (p=0.023) or control groups (p=0.017). Upon our results, we concluded that intrahippocampal injections of insulin may enhance memory for a simple learning task which supports the concept that insulin possibly plays an endogenous role in memory formation.     

Electrical stimulation of the pedunculopontine tegmental nucleus in freely moving awake rats: time- and site-specific effects on two-way active avoidance conditioning

The pedunculopontine tegmental nucleus (PPTg) is involved in the regulation of thalamocortical transmission and of several functions related to ventral and dorsal striatal circuits. Stimulation of the PPTg in anesthetized animals increases cortical arousal, cortical acetylcholine release, bursting activity of mesopontine dopaminergic cells, and striatal dopamine release. It was hypothetized that PPTg stimulation could improve learning by enhancing cortical arousal and optimizing the activity of striatal circuits. We tested whether electrical stimulation (ES) of the PPTg, applied to freely-moving awake rats previously implanted with a chronic electrode, would improve the acquisition and/or the retention of two-way active avoidance conditioning, and whether this effect would depend on the specific PPTg region stimulated (anterior vs posterior) and on the time of ES: just before (pre-training) or after (post-training) each of three training sessions. The treatment consisted of 20 min of ES (0.2 ms pulses at 100 Hz; current intensity: 40-80 microA). The results showed that (1) this stimulation did not induce either any signs of distress nor abnormal behaviors, apart from some motor stereotyped behaviors that disappeared when current intensity was lowered; (2) pre-training ES applied to the anterior PPTg improved the acquisition of two-way active avoidance, (3) no learning improvement was found after either post-training ES of the anterior PPTg, or pre- and post-training ES of the posterior PPTg. The results give support to a role of PPTg in learning-related processes, and point to the existence of functional PPTg regions.     

The role of pre-exposure to novel food tastes in activity-based conditioned taste avoidance

Rats were given differential exposure to three distinct and novel foods. One of these foods was exposed for 7 days; another for 2 days, and the last was not exposed. Next, half of the rats received six daily sessions in which a compound of the three flavors was followed by opportunities to run in wheels. The other rats received the food compound but without wheel running. On the next day, all rats were given a choice among the three food flavors presented concurrently in separate dishes. When the compound food had been followed by wheel running, rats ate little of the food given no pre-exposure, more of the food given 2 days of pre-exposure, and considerably more of the food given 7 days of pre-exposure. In comparison, rats who did not receive an opportunity to run ate equal and moderate amounts of the three foods. The results suggest that pre-exposure to a food’s taste produces latent inhibition that interferes with conditioned taste avoidance produced by pairing a taste (CS) with wheel running (US).     

The impact of experiential avoidance on the reduction of depression in treatment for borderline personality disorder

Background

Reducing symptoms of depression is an important target in the treatment of borderline personality disorder (BPD). Although current treatments for BPD are effective in reducing depression, the average post-treatment level of depression remains high.

Aim

To test whether experiential avoidance (EA) impedes the reduction of depression during treatment for BPD.

Method

EA and depression were assessed in 81 clients at baseline and 4-month intervals during 1 year of therapy. Simple correlations, hierarchical linear modeling, and latent difference score models were used to investigate the association between self-reports of EA and both self-reports and observer-based ratings of depression.

Results

EA was positively associated with greater severity of depression at all points of assessment, and changes in EA were positively associated with changes in depression. Moreover, EA significantly predicted less subsequent reduction in depression whereas no such effect was found for depression on subsequent EA.

Conclusion

The findings are consistent with the hypothesis that EA impedes the reduction of depression in the treatment of BPD and should thus be considered an important treatment target.     

Unconstraining theories of embodied cognition

The approach/avoidance effect refers to the finding that valenced stimuli trigger approach and avoidance actions. Markman and Brendl [Markman, A. B., & Brendl, M. (2005). Constraining theories of embodied cognition. Psychological Science, 16, 6-16] argued that this effect is not a truly embodied phenomenon, but depends on participants’ symbolic representation of the self.In their study, participants moved valenced words toward or away from their own name on the computer screen. This would induce participants to form a ‘disembodied’ self-representation at the location of their name, outside of the body. Approach/avoidance effects occurred with respect to the participant’s name, rather than with respect to the body.In three experiments, we demonstrate that similar effects are found when the name is replaced by a positive word, a negative word or even when no word is presented at all. This suggests that the ‘disembodied self’ explanation of Markman and Brendl is incorrect, and that their findings do not necessarily constrain embodied theories of cognition.     

Interpersonal attachment predicts identification with groups

We propose a model documenting the relationship between interpersonal attachment style and identification with groups. We hypothesized that following threat to a romantic interpersonal relationship higher attachment anxiety would be associated with lowered tendencies to identify with groups. In two studies using varied social groups we observed support for this hypothesis. In Experiment 1 we found that participants higher in attachment anxiety identified less with a salient ingroup after imagining a distressing argument with their romantic partner. In Experiment 2 we replicated these findings using an implicit measure of social identification and additionally observed a moderating role for attachment avoidance. We discuss the implications of these findings for theoretical models of interpersonal attachment and social identification.     

Mediating and Moderating Processes in the Relation between Maltreatment and Psychopathology: Mother-Child Relationship Quality and Emotion Regulation

The present study investigated underlying processes of the effect of maltreatment on psychopathology (i.e., internalizing and externalizing problems) in a group of 111 maltreated and 110 nonmaltreated 7–10 year-old children (60% boys). We tested the moderating and/or mediating roles of emotion regulation and the mother-child relationship quality (pattern of relatedness) using Structural Equation Modeling. Emotion regulation, but not the pattern of relatedness, mediated the relation between maltreatment and psychopathology. This mediation was moderated by the pattern of relatedness: For the group of children with an insecure pattern of relatedness, maltreatment was related to lower levels of emotion regulation, which was predictive of higher levels of internalizing and externalizing symptomatology. In contrast, for the secure relatedness group, there was no mediation by emotion regulation since the impact of maltreatment on emotion regulation was not significant. Implications of the mediating role of emotion regulation and the buffering role of the mother-child relationship quality were discussed.

Attachment representations in mothers of preterm infants

The aim of the study was to assess attachment representations in mothers of preterm infants using the Working Model of Child Interview (WMCI) at the 12 months of the infant's corrected age. In addition, the relation between WMCI representation categories and the Edinburgh Postnatal Depression Scale score at 6 months of the infant's corrected age was studied. There were 38 mothers of preterm infants (<1500 g or <32 gestational weeks) and 45 mothers of full-term infants. The results showed no differences between the study groups in the distribution of the three main representation categories (balanced, disengaged and distorted). However, there were qualitative differences in representations between the groups. Furthermore, maternal depression symptoms were associated with distorted representation category. We suggest that despite the qualitative differences in the mothers’ representations, mothers of preterm infants are as likely to form balanced attachments with their infants as mothers of full-term infants.     

Adult attachment, perceived stress, and PTSD among civilians exposed to ongoing terrorist attacks in Southern Israel

This study examined the relationships among exposure to terrorism, individual differences in adult attachment dimensions, perceived stress, and posttraumatic stress disorder (PTSD). A representative sample of 254 adults who had experienced more than 7 years of ongoing exposure (OGE) to rocket and mortar fire in southern Israel was compared to 308 individuals with no exposure (NE) to terrorism. OGE individuals reported significantly elevated levels of insecure attachment, perceived stress, and PTSD-symptoms as compared to the NE individuals. The associations between perceived stress and PTSD-symptoms were significantly stronger in the OGE group, compared to the NE group. For OGE individuals, the elevated level of perceived stress mediated the association between Attachment Anxiety and PTSD-symptoms. Theoretical and clinical implications of the findings are discussed.     

Uncertainty Avoidance Influences Choices for Potential Gains but not Losses

Uncertainty of outcomes is a primary dimension underlying human judgment and decision making, and is a defining feature of risk. Even though uncertainty almost always exists in decision making contexts, individuals and cultures vary in their preference for avoiding uncertainty. This study examines how uncertainty avoidance influences judgments involving uncertain and risky alternatives. Participants were presented with problems that involve potential gains or losses and contain options reflecting uncertain or certain outcomes. Greater uncertainty avoidance predicted choices for uncertain outcomes that involved gains, which tend to promote risk aversion, but not for uncertain outcomes that led to losses, which tend to promote risk seeking. These results demonstrate that culturally-relevant dispositions such as uncertain avoidance can have complex effects on judgment.