Domain‐specific contributions of biological sex and sex hormones to what,where and when components of episodic‐like memory in adult rats

Episodic memory involves the integration and recall of discrete events that include information about what happened, where it happened and when it occurred. Episodic memory function is critical to daily life, and its dysfunction is both a first identifiable indicator and an enduring core feature of cognitive decline in ageing and in neuropsychiatric disorders including Alzheimer's disease and schizophrenia. Available evidence from human studies suggests that biological sex and sex hormones modulate episodic memory function in health and disease. However, knowledge of how this occurs is constrained by the limited availability and underutilization of validated animal models in investigating hormone impacts on episodic‐like memory function. Here, adult female, adult male and gonadally manipulated adult male rats were tested on the what–where–when episodic‐like memory task to determine whether rats model human sex differences in episodic memory and how the hormonal milieu impacts episodic‐like memory processes in this species. These studies revealed salient ways in which rats model human sex differences in episodic memory, including a male advantage in spatial episodic memory performance. They also identified domain‐specific roles for oestrogens and androgens in modulating what, where and when discriminations in male rats that were unlike those engaged in corresponding novel object recognition and novel object location tasks. These studies thus identify rats and the what–where–when task as suitable for investigating the neuroendocrine bases of episodic‐like memory, and provide new information about the unique contributions that sex and sex hormones make to this complex mnemonic process.     

A Comparison of Metaphor Modality and Appeals in the Context of Skin Cancer Prevention

Health communication experts continually seek out effective strategies to strengthen persuasive campaigns. While there is evidence that verbal metaphors can improve persuasion, little attention has been given to the potential of visual metaphors to enhance health communication effects. To fill this gap, an experiment was conducted to test the effects of metaphor modality (visual vs. verbal) and type of fear appeal used (death-based or appearance-based) on skin protection intentions. Additionally, the moderating role of an individual characteristic (need for cognition), and the mediating role of two processing outcomes (message elaboration and perceived message effectiveness) were examined. Results indicated that there was no significant difference between the main effects of metaphor modality and type of fear appeal, but these message features interacted making the death-based fear appeal the most effective strategy. Need for cognition directly affected perceptions of effectiveness but did not affect skin protection intentions nor message elaboration. Of the two message processing outcomes examined, only perceived message effectiveness mediated the relationship between metaphor modality and skin protection intentions. Theoretical explanations and practical implications are discussed.     

Working memory training and brain structure and function in extremely preterm or extremely low birth weight children

This study in children born extremely preterm (EP; <28 weeks’ gestational age) or extremely low birth weight (ELBW; <1,000 g) investigated whether adaptive working memory training using Cogmed® is associated with structural and/or functional brain changes compared with a placebo program. Ninety‐one EP/ELBW children were recruited at a mean (standard deviation) age of 7.8 (0.4) years. Children were randomly allocated to Cogmed or placebo (45‐min sessions, 5 days a week over 5–7 weeks). A subset had usable magnetic resonance imaging (MRI) data pretraining and 2 weeks posttraining (structural, n = 48; diffusion, n = 43; task‐based functional, n = 18). Statistical analyses examined whether cortical morphometry, white matter microstructure and blood oxygenation level‐dependent (BOLD) signal during an n‐back working memory task changed from pretraining to posttraining in the Cogmed and placebo groups separately. Interaction analyses between time point and group were then performed. There was a significant increase in neurite density in several white matter regions from pretraining to posttraining in both the Cogmed and placebo groups. BOLD signal in the posterior cingulate and precuneus cortices during the n‐back task increased from pretraining to posttraining in the Cogmed but not placebo group. Evidence for group‐by‐time interactions for the MRI measures was weak, suggesting that brain changes generally did not differ between Cogmed and placebo groups. Overall, while some structural and functional MRI changes between the pretraining and posttraining period in EP/ELBW children were observed, there was little evidence of training‐induced neuroplasticity, with changes generally identified in both groups. Trial registration Australian New Zealand Clinical Trials Registry, anzctr.org.au ; ACTRN12612000124831.     

Sunao Tawara : further musings on his tribulations in providing the basis for the modern-day understanding of cardiac electrophysiology

Sunao Tawara, who was born in 1873 and died in 1952, is considered the father of modern cardiac electrophysiology. He published his monumental monograph de     

Social capital and psychosis: a scoping review

Social Psychiatry and Psychiatric Epidemiology - Social capital has been studied as a risk factor for psychotic disorders. The purpose of this scoping review was to scope the literature and...