Learning strategy selection in the water maze and hippocampal CREB phosphorylation differ in two inbred strains of mice

Learning strategy selection was assessed in two different inbred strains of mice, C57BL/6 and DBA/2, which are used for developing genetically modified mouse models. Male mice received a training protocol in a water maze using alternating blocks of visible and hidden platform trials, during which mice escaped to a single location. After training, mice were required to choose between the spatial location where the platform had been during training (a place strategy) and a visible platform presented in a new location (a cued/response strategy). Both strains of mice had similar escape performance on the visible and hidden platform trials during training. However, in the strategy preference test, C57BL/6 mice selected a place strategy significantly more often than DBA/2 mice. Because much evidence implicates the hippocampus and striatum as important neural substrates for spatial/place and cued/response learning, respectively, the engagement of the hippocampus was then assessed after either place or cue training by determining levels of cAMP response element-binding protein (CREB) and phosphorylated CREB (pCREB) in these two mouse strains. Results revealed that hippocampal CREB levels in both strains of mice were significantly increased after place in comparison to cued training. However, the relation of hippocampal pCREB levels to training was strain dependent; pCREB was significantly higher in C57BL/6 mice than in DBA/2 mice after place training, while hippocampal pCREB levels did not differ between strains after cued training. These findings indicate that pCREB, specifically associated with place/spatial training, is closely tied to differences in spatial/place strategy preference between C57BL/6 and DBA/2 mice.     

The effect of alcohol administration on human timing: a comparison of prospective timing, retrospective timing and passage of time judgements

Previous research suggests that human timing may be affected by alcohol administration. The current study aimed to expand on previous research by examining the effect of alcohol on prospective timing, retrospective timing and passage of time judgements. A blind between-subjects design was employed in which participants were either administered 0 g of alcohol per kilogramme of body weight (placebo), 0.4 g/kg (low dose) or 0.6 g/kg (high dose). Participants completed four types of temporal task; verbal estimation and temporal generalisation, a retrospective timing task and a passage of time judgement task. A high dose of alcohol resulted in overestimations of duration relative to the low dose and placebo group in the verbal estimation task. A high dose of alcohol was also associated with time passing more quickly than normal. Alcohol had no effect on retrospective judgements. The results suggest that a high dose of alcohol increases internal clock speed leading to over-estimations of duration on prospective timing tasks, and the sensation of time passing more quickly than normal. The absence of an effect of alcohol on retrospective timing supports the suggestion that retrospective judgements are not based on the output of an internal clock.     

Frequency of Interpersonal Trauma Types,Avoidant Attachment,Self-Compassion,and Interpersonal Competence: A Model of Persisting Posttraumatic Symptoms

Given limited knowledge about how psychosocial factors interact to modulate posttraumatic stress symptoms, this study evaluated an integrative model proposing that experiencing more interpersonal trauma types (e.g., abuse, assault, rape, etc.) leads to greater avoidant attachment and lower self-compassion, which limits the development and use of effective interpersonal skills. In turn, lower levels of self-compassion and interpersonal competence perpetuate posttraumatic symptoms. Anonymous trauma-experienced adults (n = 132) completed self-report measures in an online study hyperlinked on trauma support websites. Data were subjected to confirmatory factor analysis and structural equation modeling, which provided support for the hypothesized model. Specifically, higher frequency of interpersonal trauma types experienced was linked to higher avoidant attachment and lower self-compassion, which in turn were associated with lower interpersonal competence, which correlated with greater posttraumatic stress symptoms. Although cross-sectional data cannot address directionality of associations, this study’s findings emphasize the potential utility of future longitudinal research designed to examine possible causal relationships among these specific psychosocial factors. For example, study findings suggest that those who experience more types of interpersonal trauma and who are characterized by avoidant attachment and lower self-compassion and interpersonal competence may be the most susceptible to experiencing severe posttraumatic symptoms. However, findings also suggest that efforts to increase self-compassion and interpersonal skills may help reduce symptoms.     

Linguistic correlates of self in deceptive oral autobiographical narratives

The current study collected orally-delivered autobiographical narratives from a sample of 44 undergraduate students. Participants were asked to produce both deceptive and non-deceptive versions of their narrative to two specific autobiographical question prompts while standing in front of a video camera. Narratives were then analyzed with Coh-Metrix software on 33 indices of linguistic cohesion. Following a Bonferroni correction for the large number of linguistic variables (p < .002), results indicated that the deceptive narratives contained more explicit action verbs, less linguistic complexity, and less referential coherence (sentences being cohesive with each other). The results support a theory that, in deceptive narratives, there is greater narrative distance between the self that narrates and the self that is narrated about. This suggests that narrative selves are constituted not as autonomous selves, but are subject to processes (e.g., psychological, linguistic, social) that are likely operating on a subconscious level.