Training and transfer effects in task switching

Performance on task switching, a paradigm commonly used to measure executive function, has been shown to improve with practice. However, no study has tested whether these benefits are specific to the tasks learned or are transferable to new situations. We report evidence of transferable improvement in a cued, randomly switching paradigm as measured by mixing cost, but we report no consistent improvement for switch cost. Improvement in mixing costs arises from a relative reduction in time to perform both switch and nonswitch trials that immediately follow switch trials, implicating the ability to recover from unexpected switches as the source of improvement. These results add to a growing number of studies demonstrating generalizable improvement with training on executive processing.     

Aging, Training, and the Brain: A Review and Future Directions

As the population ages, the need for effective methods to maintain or even improve older adults’ cognitive performance becomes increasingly pressing. Here we provide a brief review of the major intervention approaches that have been the focus of past research with healthy older adults (strategy training, multi-modal interventions, cardiovascular exercise, and process-based training), and new approaches that incorporate neuroimaging. As outcome measures, neuroimaging data on intervention-related changes in volume, structural integrity; and functional activation can provide important insights into the nature and duration of an intervention’s effects. Perhaps even more intriguingly, several recent studies have used neuroimaging data as a guide to identify core cognitive processes that can be trained in one task with effective transfer to other tasks that share the same underlying processes. Although many open questions remain, this research has greatly increased our understanding of how to promote successful aging of cognition and the brain.     

How are visuospatial working memory, executive functioning, and spatial abilities related? A latent-variable analysis.

This study examined the relationships among visuospatial working memory (WM) executive functioning, and spatial abilities. One hundred sixty-seven participants performed visuospatial short-term memory (STM) and WM span tasks, executive functioning tasks, and a set of paper-and-pencil tests of spatial abilities that load on 3 correlated but distinguishable factors (Spatial Visualization, Spatial Relations, and Perceptual Speed). Confirmatory factor analysis results indicated that, in the visuospatial domain, processing-and-storage WM tasks and storage-oriented STM tasks equally implicate executive functioning and are not clearly distinguishable. These results provide a contrast with existing evidence from the verbal domain and support the proposal that the visuospatial sketchpad may be closely tied to the central executive. Further, structural equation modeling results supported the prediction that, whereas they all implicate some degree of visuospatial storage, the 3 spatial ability factors differ in the degree of executive involvement (highest for Spatial Visualization and lowest for Perceptual Speed). Such results highlight the usefulness of a WM perspective in characterizing the nature of cognitive abilities and, more generally, human intelligence.     

Exercise Training for Persons with Alzheimer's Disease and Caregivers: A Review of Dyadic Exercise Interventions

Alzheimer's disease (AD) is the most common form of dementia and the prevalence will increase dramatically in the next decades. Although exercise has shown benefits for people with dementia due to AD as well as their caregivers, the impact of a dyadic exercise intervention including both groups as study participants remains to be determined. The authors review the current clinical evidence for dyadic exercise interventions, which are exercise regimens applied to both the person with dementia and the caregiver. A total of 4 controlled trials were reviewed. This review shows that dyadic exercise interventions are feasible and may produce a positive effect on functional independence and caregiver burden. However, there was insufficient evidence to support a benefit of dyadic exercise intervention on cognitive performance and on behavioral and neuropsychiatric symptoms in participants with dementia due to AD. A dyadic exercise intervention improves functional independence and caregiver burden. However, there is a need for well-designed randomized controlled clinical trials to confirm these benefits and to investigate several important points such as the effects of a dyadic exercise intervention on cognitive and noncognitive outcomes of AD, the optimal intensity of exercise training, and the cost effectiveness of such a program.     

The relationship between dynamic strain aging and serrated flow behaviour in magnesium alloy

The relationship between dynamic strain ageing (DSA) and serrated flow has been investigated via alternately switching strain rates at various temperatures in a Mg–3Nd–1Zn alloy. The results reveal that serrated flow is enhanced with decreasing strain rate and increasing temperature and tends to vanish, while the DSA continually intensifies as revealed by a higher flow stress even after the serration flow disappears. A mechanism is proposed, which could explain some abnormal deformation behaviour, such as a negative strain rate sensitivity and thermal hardening.     

Risk avoidance: Graphs versus numbers

There have long been speculations that graphical and numerical presentations of risk statistics differ in their impact on people’s willingness to pursue actions that could harm or even kill them. But research has been unclear about the processes whereby the pictorial character of graphical displays per se might affect those risky decisions or even whether such effects actually occur. In two studies, we demonstrate that the pictorial nature of a graphical risk display can, indeed, increase risk avoidance. This increase is associated with a heightened impression of the riskiness of less safe alternatives. The results suggest that this picture-driven, intensified sense of riskiness, in turn, rests on two kinds of mechanisms: one cognitive, the other affective. Cognitively, pictorial presentations impose weaker upper bounds on people’s internal representations of the chances that riskier alternatives will bring about actual harm. Affectively, pictures ignite stronger, more aversive negative associations with riskier options and their outcomes.     

The motivational looking glass: how significant others implicitly affect goal appraisals

Three studies manipulate the accessibility of significant-other representations to explore how these representations may automatically influence how goals are construed and experienced. Study 1 finds that the perceived attainment expectations of a significant other automatically affect participants' own task-goal expectations and their subsequent task performance and persistence. Study 2 finds that the general perceived value that a significant other places in attaining a task goal automatically affects participants' own attainment value appraisals, their task persistence and performance, and the magnitude of their reaction to success and failure feedback. Finally, Study 3 demonstrates that the regulatory focus prescribed by a significant other may automatically affect participants' own regulatory focus with regards to a task goal, with consequences for their cheerfulness-dejection and relaxation-agitation responses to success and failure feedback. The implications for our understanding of social influence and self-regulation are discussed.     

Forgetting all else: on the antecedents and consequences of goal shielding

Six studies explore the role of goal shielding in self-regulation by examining how the activation of focal goals to which the individual is committed inhibits the accessibility of alternative goals. Consistent evidence was found for such goal shielding, and a number of its moderators were identified: Individuals' level of commitment to the focal goal, their degree of anxiety and depression, their need for cognitive closure, and differences in their goal-related tenacity. Moreover, inhibition of alternative goals was found to be more pronounced when they serve the same overarching purpose as the focal goal, but lessened when the alternative goals facilitate focal goal attainment. Finally, goal shielding was shown to have beneficial consequences for goal pursuit and attainment.