Exploring the effects of demonstration and enactment in facilitating recall of instructions in working memory

Across the lifespan the ability to follow instructions is essential for the successful completion of a multitude of daily activities. This ability will often rely on the storage and processing of information in working memory, and previous research in this domain has found that self-enactment at encoding or observing other-enactment at encoding (demonstration) improves performance at recall. However, no working memory research has directly compared these manipulations. Experiment 1 explored the effects of both self-enactment and demonstration on young adults’ (N=48) recall of action-object instruction sequences (e.g. ‘spin the circle, tap the square’). Both manipulations improved recall, with demonstration providing relatively larger boosts to performance across conditions. More detailed analyses suggested that this improvement was driven by improving the representations of actions, rather than objects, in these action-object sequences. Experiment 2 (N=24) explored this further, removing the objects from the physical environment and comparing partial demonstration (i.e. action-only or object-only) with no or full demonstration. The results showed that partial demonstration only benefitted features that were demonstrated, while full demonstration improved memory for actions, objects and their pairings. Overall these experiments indicate how self-enactment, and particularly demonstration, can benefit verbal recall of instruction sequences through the engagement of visuo-motor processes that provide additional forms of coding to support working memory performance

Exploring the understanding and experience of working memory in teaching professionals: A large-sample questionnaire study

Working memory (WM) underpins learning and is strongly associated with academic achievement. Children with poor WM need support in the classroom, but little is known about teachers’ understanding of WM. An online questionnaire (N = 1425) assessed educational professionals’ understanding of key concepts related to WM. Respondents generally showed some understanding, although most overestimated WM duration. There was also considerable variability in the signs identified as being associated with poor WM and possible strategies to assist such children. This demonstrates the need to provide teacher training about WM, and for collaboration between researchers and teachers in developing support materials

Can children prioritize more valuable information in working memory? An exploration into the effects of motivation and memory load

Recent research found no evidence that children aged 7-10 years are able to direct their attention to more valuable information in working memory. The current experiments examined whether children demonstrate this ability when the reward system used to motivate participants is engaging and age-appropriate. This was explored across different memory loads (3 vs 4 item arrays) and modes of presentation (sequential vs simultaneous). Younger (7-8 years) and older children (9-10 years) were shown three or four colored shapes and asked to recall the color of one probed item following a brief delay. Items were either presented sequentially (Experiment 1) or simultaneously (Experiment 2). Children completed a differential probe value condition, in which the first shape (Experiment 1) or the top-left shape (Experiment 2) was worth more ‘points’ than the other items, and an equal probe value condition, in which all shapes were equally valuable. Children were told they could use the points collected to play a specially-designed game at the end of the session, and that they would be given a prize if they collected enough points. When items were presented sequentially, significant probe value effects emerged, with children showing higher accuracy for the first item when this serial position was more valuable. This effect was consistent across age group and memory load. When items were encountered simultaneously, both groups showed probe value effects in the higher (4 item) memory load condition. This indicates that children can prioritize more valuable information in working memory when sufficiently motivated to do so

The effect of a verbal concurrent task on visual precision in working memory

By investigating the effect of individualized verbal load on a visual working memory task, we investigated whether working memory is better captured by modality specific stores or a general attentional resource. A visual measure was used that allows for the precision of representations in working memory to be quantified. Bayesian analyses were employed to contrast the likelihood of our data assuming a small versus a large effect, as predicted by the differing accounts. We found evidence that the effect of verbal load on visual precision and binary feature recall was small. The results were indeterminate for the size of the dual-task effect on verbal accuracy and the probability of recalling a continuous target feature. These results, in part, support a multiple component account of working memory. An analysis of how the chosen effect intervals affect the results is also reported, highlighting the importance of making specific predictions in the literature

Water and sodium intake habits and status of ultra-endurance runners during a multi-stage ultra-marathon conducted in a hot ambient environment: an observational field based study

<p>Abstract</p> <p>Background</p> <p>Anecdotal evidence suggests ultra-runners may not be consuming sufficient water through foods and fluids to maintenance euhydration, and present sub-optimal sodium intakes, throughout multi-stage ultra-marathon (MSUM) competitions in the heat. Subsequently, the aims were primarily to assess water and sodium intake habits of recreational ultra-runners during a five stage 225 km semi self-sufficient MSUM conducted in a hot ambient environment (T_max range: 32°C to 40°C); simultaneously to monitor serum sodium concentration, and hydration status using multiple hydration assessment techniques.</p> <p>Methods</p> <p>Total daily, pre-stage, during running, and post-stage water and sodium ingestion of ultra-endurance runners (UER, <it>n</it> = 74) and control (CON, <it>n</it> = 12) through foods and fluids were recorded on Stages 1 to 4 by trained dietetic researchers using dietary recall interview technique, and analysed through dietary analysis software. Body mass (BM), hydration status, and serum sodium concentration were determined pre- and post-Stages 1 to 5.</p> <p>Results</p> <p>Water (overall mean (SD): total daily 7.7 (1.5) L/day, during running 732 (183) ml/h) and sodium (total daily 3.9 (1.3) g/day, during running 270 (151) mg/L) ingestion did not differ between stages in UER (<it>p</it> < 0.001 <it>vs</it>. CON). Exercise-induced BM loss was 2.4 (1.2)% (<it>p</it> < 0.001). Pre- to post-stage BM gains were observed in 26% of UER along competition. Pre- and post-stage plasma osmolality remained within normal clinical reference range (280 to 303 mOsmol/kg) in the majority of UER (<it>p</it> > 0.05 <it>vs</it>. CON pre-stage). Asymptomatic hyponatraemia (<135 mmol/L) was evident pre- and post-stage in <it>n</it> = 8 UER, corresponding to 42% of sampled participants. Pre- and post-stage urine colour, urine osmolality and urine/plasma osmolality ratio increased (<it>p</it> < 0.001) as competition progressed in UER, with no change in CON. Plasma volume and extra-cellular water increased (<it>p</it> < 0.001) 22.8% and 9.2%, respectively, from pre-Stage 1 to 5 in UER, with no change in CON.</p> <p>Conclusion</p> <p>Water intake habits of ultra-runners during MSUM conducted in hot ambient conditions appear to be sufficient to maintain baseline euhydration levels. However, fluid over-consumption behaviours were evident along competition, irrespective of running speed and gender. Normonatraemia was observed in the majority of ultra-runners throughout MSUM, despite sodium ingestion under benchmark recommendations.</p

Role of AMP-Activated Protein Kinase on Steroid Hormone Biosynthesis in Adrenal NCI-H295R Cells

Regulation of human androgen biosynthesis is poorly understood. However, detailed knowledge is needed to eventually solve disorders with androgen dysbalance. We showed that starvation growth conditions shift steroidogenesis of human adrenal NCI-H295R cells towards androgen production attributable to decreased HSD3B2 expression and activity and increased CYP17A1 phosphorylation and 17,20-lyase activity. Generally, starvation induces stress and energy deprivation that need to be counteracted to maintain proper cell functions. AMP-activated protein kinase (AMPK) is a master energy sensor that regulates cellular energy balance. AMPK regulates steroidogenesis in the gonad. Therefore, we investigated whether AMPK is also a regulator of adrenal steroidogenesis. We hypothesized that starvation uses AMPK signaling to enhance androgen production in NCI-H295R cells. We found that AMPK subunits are expressed in NCI-H295 cells, normal adrenal tissue and human as well as pig ovary cells. Starvation growth conditions decreased phosphorylation, but not activity of AMPK in NCI-H295 cells. In contrast, the AMPK activator 5-aminoimidazole-4-carboxamide (AICAR) increased AMPKα phosphorylation and increased CYP17A1-17,20 lyase activity. Compound C (an AMPK inhibitor), directly inhibited CYP17A1 activities and can therefore not be used for AMPK signaling studies in steroidogenesis. HSD3B2 activity was neither altered by AICAR nor compound C. Starvation did not affect mitochondrial respiratory chain function in NCI-H295R cells suggesting that there is no indirect energy effect on AMPK through this avenue. In summary, starvation-mediated increase of androgen production in NCI-H295 cells does not seem to be mediated by AMPK signaling. But AMPK activation can enhance androgen production through a specific increase in CYP17A1-17,20 lyase activity