The Impact of Motor Activity and Inactivity on the Brain: Implications for the Prevention and Treatment of Nervous- System Disorders

ABSTRACT— Since Donald Hebb's pioneering observations in the 1940s, much research has focused on the effects of variations in physical activity and environmental complexity on behavioral performance and brain structure. Beneficial effects on brain health have been linked to physical fitness, skilled training, and exposure to complex environments, though in rodents these effects may be negated by sudden changes in social structure. Such manipulations can alleviate the deficits associated with several nervous-system disorders and aging. But how increased activity produces its beneficial effects is still not fully understood. How does unskilled physical activity (e.g., repetitive exercise) compare to training in skilled activities or exposure to complex environments? In injury states, is task-specific training a better rehabilitative strategy than general exercise? How do changes in motor activity affect specific brain regions, and can the intensity and timing of therapeutic movement be adjusted to produce optimal outcomes? Are the beneficial effects of motor enrichment banked over periods of inactivity and can they be called upon with booster training to treat a later neurological disorder? Are there circumstances in which increased activity is harmful? Enrichment of physical activity shows promise as an easy and healthful means for improving or restoring brain function, and questions like these are now being investigated so that the full potential of increased activity may be harnessed.     

Young infants' actions reveal their developing knowledge of support variables: converging evidence for violation-of-expectation findings

Violation-of-expectation (VOE) tasks have revealed substantial developments in young infants' knowledge about support events: by 5.5 months, infants expect an object to fall when released against but not on a surface; and by 6.5 months, infants expect an object to fall when released with 15% but not 100% of its bottom on a surface. Here we investigated whether action tasks would reveal the same developmental pattern. Consistent with VOE reports, 5.5- and 6.5-month-old infants were more likely to reach for a toy that rested on as opposed to against a surface; and 6.5- but not 5.5-month-olds were more likely to reach for a toy with 100% as opposed to 15% of its bottom on a surface. Infants at each age thus used their support knowledge to determine whether the toys were likely to be retrievable or to be attached to adjacent surfaces and hence irretrievable. These and control findings extend recent evidence that developmental patterns observed in VOE tasks also hold in action tasks, and as such provide further support for the view that VOE and action tasks tap the same physical knowledge.     

Mediators of behavior change in two tailored physical activity interventions for adolescent girls

ObjectivesIt has been suggested that the lack of knowledge regarding the mechanisms responsible for behavior change may be responsible for the low levels of effectiveness in physical activity interventions among youth. While it is common for physical activity interventions to cite a theoretical framework, few test the validity of their constructs using an established mediation analysis technique. The purpose of this study was to identify mediators of physical activity behavior change in two tailored interventions for adolescent girls.DesignThis study involved an experimental design.MethodsParticipants (N=161) were randomly allocated to a control (CON) group, an intervention based on the Health Promotion (HP) Model or an intervention developed from the HP Model that included two processes from the Transtheoretical Model (THP). Both interventions included school-based education sessions, individual counseling sessions, and two physical activity sessions completed with the participants' mothers. Measures were assessed prior to the intervention, at post-intervention and at a 6-month follow-up. The following constructs were included in the mediation analyses: perceived benefits, perceived barriers, self-efficacy, exposure to models, social support, interpersonal norms, planning, stimulus control, and counterconditioning.ResultsPerceived benefits, perceived barriers, self-efficacy, and commitment to planning satisfied the criteria for mediation in the THP intervention. Self-efficacy and commitment to planning were identified as mediators in the HP intervention.ConclusionThe results of this study provide evidence that both interventions were successful in increasing physical activity through changes in the theoretical constructs.     

Can infants be "taught" to attend to a new physical variable in an event category? The case of height in covering events

As they observe or produce events, infants identify variables that help them predict outcomes in each category of events. How do infants identify a new variable? An explanation-based learning (EBL) account suggests three essential steps: (1) observing contrastive outcomes relevant to the variable; (2) discovering the conditions associated with these outcomes; and (3) generating an explanation for the condition-outcome regularity discovered. In Experiments 1-3, 9-month-old infants watched events designed to "teach" them the variable height in covering events. After watching these events, designed in accord with the EBL account, the infants detected a height violation in a covering event, three months earlier than they ordinarily would have. In Experiments 4-6, the "teaching" events were modified to remove one of the EBL steps, and the infants no longer detected the height violation. The present findings thus support the EBL account and help specify the processes by which infants acquire their physical knowledge.     

基于自我相似面孔的亲缘选择与配偶选择行为

根据广义适合度理论, 自我相似面孔与亲缘选择和配偶选择行为密切相关。自我相似面孔可以促进个体的亲缘利他行为, 影响配偶选择行为。来自“夫妻相”、“性印刻”的描述性研究数据支持自我相似面孔与配偶选择偏好之间的相关关系。来自实验研究的数据, 结论尚不统一。有些证实自我相似面孔可以引发配偶选择偏好, 有些却不支持这一结论。最近的研究从内隐及外显认知上分离择偶过程中对自我相似面孔的偏好：认为偏好是内隐的, 一旦上升到意识层面便会消失。另有研究从性选择策略上对自我相似面孔偏好的原因进行解读。对自我相似面孔偏好的神经机制的研究也有一些新的发现。未来研究可借助fMRI等工具从认知过程及神经机制上对自我相似面孔偏好的现象作进一步探讨。     

On Brain, Soul, Self, and Freedom: An Essay in Bridging Neuroscience and Faith

The article begins at the intellectual fissure between many statements coming from neuroscience and the language of faith and theology. First I show that some conclusions drawn from neuroscientific research are not as firm as they seem: neuroscientific data leave room for the interpretation that mind matters. I then take a philosophical‐theological look at the notions of soul, self, and freedom, also in the light of modern scientific research (self‐organization, neuronal networks), and present a view in which these theologically important notions are seen in relation both to matter (brain) and to God. I show that religious insights expressed with soul and free will bear a remarkable resemblance to certain insights from neuroscience and the science of complex, self‐organizing systems, including emphasis on corporeality and emphasis on organization as a form of that corporeality, and that they also show an interesting parallel — albeit described in different terms — concerning the crucial role of a valuation principle that generates attraction. With that, the common‐sense idea that freedom simply is the same as indeterminism is refuted: freedom primarily means self‐determination. I bring to the fore that the self is not a static thing but a “longing.” Such longing springs from something, and it is the relationship to this source that constitutes the self. The main concern is to point out the crucial role of attraction with respect to being and to life, and to draw attention not only to the astonishing parallel on this point between Thomas Aquinas and Alfred North Whitehead but also to a surprising — albeit more implicit — analogy between these philosophical‐theological views and scientific theories of self‐organization (such as those concerning neuronal networks). In short, being attracted toward what appears as “good” is what constitutes us as selves and what thereby signifies the primary meaning of our freedom.     

Personality and self-determination of exercise behaviour

There is extensive evidence that personality traits are associated with health-related behaviours, but less evidence regarding the underlying mechanisms. In this study, we examined the relationships between personality and self-determination of exercise behaviour. Users of a sports centre completed personality scales (the NEO Five Factor Inventory supplemented with the Eysenck Personality Questionnaire Psychoticism scale) and exercise self-determination scales (Behavioural Regulation in Exercise Questionnaire which measures extrinsic, introjected, identified and intrinsic forms of regulation). Analyses were restricted to 182 individuals in the maintenance stage of exercise participation. Partial correlation analysis was used to examine the relationships between each personality scale and the self-determination scales, controlling for other personality scales, gender and age. Neuroticism was associated with more introjected regulation, extraversion with more identified and intrinsic regulation, openness with less external regulation, conscientiousness with less external regulation and more intrinsic regulation, and psychoticism with more external regulation. Relating these findings to self-determination theory (Deci & Ryan, 2000), it is speculated that extraverted individuals are able to feel self-determined because exercise can satisfy the need for relatedness, conscientious individuals because exercise can satisfy the need for competence. Furthermore, conscientious individuals may have greater wherewithal to advance along the continuum of behavioural regulation.     

A physical critique of physical causation

The conserved quantities theory of causation (CQTC) attempts to use physics as the basis for an account of causation. However, a closer examination of the physics involved in CQTC reveals several critical failures. Some of the conserved quantities in physics cannot be used to distinguish causal interactions. Other conserved quantities cannot always be the properties of fields or particles. Finally, CQCT does not account for causal interactions that are static. I would like to thank Fred Kronz, Cory Juhl, Joshua Dever, and two anonymous referees for their many helpful suggestions and comments.     

VERB™ Summer Scorecard: Findings from a Multi-level Community-based Physical Activity Intervention for Tweens

The benefits of physical activity for adolescents are well established. Multi-level interventions may be especially effective in establishing and sustaining health-enhancing behaviors. This study explored the influences of a multi-level community intervention aimed at increasing physical activity among tweens (youth 9–13). Two Florida school districts far apart served as intervention and comparison sites in a quasi-experimental post-test design. Youth in grades 5 through 8 in the intervention community (n = 1,253) and comparison community (n = 866) completed an anonymous post-intervention survey. An intent-to-treat analysis did not show any statistically significant group differences for the physical activity outcomes examined. However, a subset analysis revealed that students who reported participating in the intervention were more likely to be physically active than youth in the comparison group, as well as youth in the intervention community who reported not participating. Participating in the intervention was significantly related to meeting recommendations for vigorous physical activity (OR = 2.08, P = 0.0259), being physically active on weekends (OR = 1.84, P = 0.0017), and reporting more days of trying a new game or sport (OR = 1.49, P = 0.046) after controlling for grade, gender, race/ethnicity, and SES. These findings support the efficacy of multi-level interventions to create effective health behavior change, especially when linkages among community, media, schools, and the home are present.