Executive function in the classroom: Cognitive flexibility supports reading fluency for typical readers and teacher-identified low-achieving readers

BackgroundDominant explanations of reading fluency indicate automatic phonological decoding frees mental resources for processing meaning. However, decoding automaticity does not guarantee attention to meaning. Recent neurocognitive work suggests executive functioning (EF) may contribute to fluency beyond decoding automaticity.AimsTwo studies examined contributions of an understudied EF, cognitive flexibility, to fluent reading and tested a teacher-administered EF intervention to improve fluency in teacher-identified low-achieving (LA) readers.Methods and proceduresStudy 1 assessed word reading fluency, automatic decoding, reading comprehension, verbal and nonverbal ability, and reading-specific and domain-general cognitive flexibility in 50 1st and 2nd grade typically-developing (TD) readers. Study 2 compared TD and LA readers’ cognitive flexibility and examined effectiveness of cognitive flexibility intervention for improving fluency in 33 LA 2nd and 3rd graders.Outcomes and resultsReading-specific flexibility contributed to fluency beyond automatic decoding and all other control variables in TD readers who had significantly higher cognitive flexibility than LA readers. Teacher-administered EF intervention improved reading fluency for LA readers.Conclusions and implicationsThese findings expand understanding of the neurocognitive basis of reading fluency and add to the growing body of evidence that EF underlies learning differences and serves as a useful target of intervention for LA students.     

心理弹性研究现状

心理弹性（Resilience ）最早是由美国心理学家Anthony于20世纪70年代提出的，它以一种全新的视角来看待个体的应激反应，并在心理学、临床医学、教育学等各学科日益受到重视，现已成为国际心理学界研究的热点［1］。心理弹性与心理健康存在密切关系，在人们的压力应对中起着决定性的作用［2］，是降低心理应激反应、提高生活满意度的重要预测因子，有益于获得创伤后的新生［3］。笔者就心理弹性的概念及国内外研究进展进行综述，以期为我国的护理临床研究提供新视角。     

Evolutionary emergence of responsive and unresponsive personalities

In many animal species, individuals differ consistently in suites of correlated behaviors, comparable with human personalities. Increasing evidence suggests that one of the fundamental factors structuring personality differences is the responsiveness of individuals to environmental stimuli. Whereas some individuals tend to be highly responsive to such stimuli, others are unresponsive and show routine-like behaviors. Much research has focused on the proximate causes of these differences but little is known about their evolutionary origin. Here, we provide an evolutionary explanation. We develop a simple but general evolutionary model that is based on two key ingredients. First, the benefits of responsiveness are frequency-dependent; that is, being responsive is advantageous when rare but disadvantageous when common. This explains why responsive and unresponsive individuals can coexist within a population. Second, positive-feedback mechanisms reduce the costs of responsiveness; that is, responsiveness is less costly for individuals that have been responsive before. This explains why individuals differ consistently in their responsiveness, across contexts and over time. As a result, natural selection gives rise to stable individual differences in responsiveness. Whereas some individuals respond to environmental stimuli in all kinds of contexts, others consistently neglect such stimuli. Interestingly, such differences induce correlations among all kinds of other traits (e.g., boldness and aggressiveness), thus providing an explanation for environment-specific behavioral syndromes.     

Novel druggable hot spots in avian influenza neuraminidase H5N1 revealed by computational solvent mapping of a reduced and representative receptor ensemble

The influenza virus subtype H5N1 has raised concerns of a possible human pandemic threat because of its high virulence and mutation rate. Although several approved anti-influenza drugs effectively target the neuraminidase, some strains have already acquired resistance to the currently available anti-influenza drugs. In this study, we present the synergistic application of extended explicit solvent molecular dynamics (MD) and computational solvent mapping (CS-Map) to identify putative 'hot spots' within flexible binding regions of N1 neuraminidase. Using representative conformations of the N1 binding region extracted from a clustering analysis of four concatenated 40-ns MD simulations, CS-Map was utilized to assess the ability of small, solvent-sized molecules to bind within close proximity to the sialic acid binding region. Mapping analyses of the dominant MD conformations reveal the presence of additional hot spot regions in the 150- and 430-loop regions. Our hot spot analysis provides further support for the feasibility of developing high-affinity inhibitors capable of binding these regions, which appear to be unique to the N1 strain.     

Brain flexibility associated with need for cognition contributes to creative achievement

Advances in graph‐theoretic models of networks have made it possible to investigate the topological properties of the human brain across time and space. Brain flexibility is defined as the frequency with which brain regions switch between different functional modules over time and has been shown to correlate with higher‐order cognitive functions. Need for cognition (NFC) refers to a personality trait to engage in and enjoy effortful cognitive endeavors and usually has a positive effect on diverse cognitive activities (e.g., creativity), which may also be closely related to brain flexibility. Here, we tested whether the flexibility of a large‐scale brain network associated with NFC facilitated creative achievement. Robust correlation analyses showed that NFC correlates with the flexibility of the insula, the medial prefrontal cortex, and the putamen at the node level. Several large‐scale brain networks whose flexibility also correlated with NFC, including the default mode network, salience network, subcortical network, ventral attention network, and control network, imply that higher NFC individuals may exhibit better cognitive abilities, such as executive control, salient detection, spontaneous thought, and motivation function. Interestingly, only global flexibility acted as a mediator in the relationship between NFC and creative achievement, suggesting that the mediating mechanism may involve an interaction between distinct regions or large‐scale networks across the entire brain instead of the functional characteristic of local regions. Together, we demonstrate that the higher NFC is, the more flexible the brain, which may provide a potential insight into the acquisition of creative achievement.