Associations of physical activity and gross motor skills with executive function in preschool children from low‐income South African settings

Executive function is foundational for cognitive development. Previous research has shown both gross motor skills and physical activity to be related to executive function. However, evidence for these relationships in the preschool years, as well as in low‐ and middle‐income countries is lacking. Therefore, this study aimed to investigate the relationships between components of executive function (inhibition, shifting and working memory) and gross motor skills (locomotor skills and object control skills) in a sample of preschool children from urban and rural low‐income settings in South Africa. Results revealed that inhibition and working memory, but not shifting, were associated with gross motor skills. More specifically: inhibition was associated with both locomotor [β = 0.20, p = 0.047] and object control skills [β = 0.24, p = 0.024], whereas working memory was only associated with locomotor skills [β = 0.21, p = 0.039]. Physical activity was not associated with inhibition and shifting but was negatively associated with working memory. These results elaborate a growing evidence base linking executive function and gross motor skills in the early years, and it is the first to look at specific associations of locomotor and object control skills with executive function in the South African context (a low‐ and middle‐income country).     

Spatial attentional distribution is modulated by head direction during eccentric gaze

Visual perception during eccentric gaze can be facilitated when a visual stimulus appears in front of the head direction. This study investigated the relative effects of gaze location and head direction on visual perception in central and peripheral vision. Participants identified the orientation of a T-shaped figure presented in the centre of a monitor and simultaneously localised a dot appearing in the periphery, while head direction relative to gaze location was to the left, right or centre. Effects of head direction were found only when the dot appeared far from the gaze fixation point, such that dot detection was superior when it appeared to the left (right) of fixation in the left (right) head direction. Experimental results indicated this was not due to a small shift of gaze location. Thus this study suggests that head direction influences visual perception particularly in peripheral vision where visual acuity decreases.     

The Effect of Vision and Surface Compliance on Balance in Untrained and Strength Athletes

The purpose of this investigation was to evaluate the effect of the removal of vision and/or surface compliance on postural stability in strength athletes who habitually use free-weights and compound movements in their training (i.e., powerlifters, Olympic weightlifters), and untrained individuals. Static and dynamic balance testing was performed with eyes open or closed on stable and memory foam surfaces. Both groups had similar increases in postural sway area and velocity during quiet standing testing; whereas group main effects and interactions for dynamic testing revealed that untrained participants experienced greater relative declines in postural performance when voluntary limits of stability are stressed, especially when both vision and surface compliance were deterred. These results demonstrate that in comparison to untrained young adults, postural control variables may be reduced to a lesser extent in strength athletes when sensory constraints are altered; however this appears to be specific to the type of postural task performed.     

Religious Naturalism and the Religion-Science Dialogue: A Minimalist View

Although its roots go back at least to Spinoza, religious naturalism is once again becoming a self–conscious option in religious thinking. This article seeks to (1) provide a generic notion of religious naturalism, (2) sketch my own "minimalist" variety of religious naturalism, and (3) view the science–religion dialogue from both of these perspectives. This last will include reflection on the nature of scientific practices, the contributions of religious traditions to moral reflection, and Ursula Goodenough's "religiopoiesis."     

小学优生与差生完成系列回忆任务错误类型发展的实验研究

主要探讨了小学优生与差生在完成系列回忆记忆任务时出现错误的发展情况。实验以小学一、三、五年级的学生作为被试,每年级优生与差生各10名。以普通(不形似,不近音)、形似和近音三种类型汉字为实验材料,要求被试按材料呈现的顺序进行回忆。结果发现：在完成系列回忆任务时,小学生表现出四种错误类型,错误率从高到低依次是：移动错误、遗漏错误、侵入错误、重复错误。每一类型的错误率都是优生显著少于差生。研究还发现四种错误受材料特点的影响,即各年级小学生错误率从高到低近音字、形似字、普通字。     

Development and Validation of a Short Health Behaviors Index for Use with Low Socioeconomic Status (SES) Older Adults

This study reports on the development and validation of a health behavior index in predominantly low socioeconomic status (SES) older adults. In order to develop and validate the index for use in low SES older adults, the 24-item Health and Human Services HealthStyle Self-Test was used for item generation. It was reduced to a relatively brief instrument, the Short HealthStyle (SHS) Index with 13 items that measures four major content areas of lifestyle behaviors among low SES older adults. The SHS Index was administered to a sample of 350 low SES older individuals. Principal component model factor analysis indicated a four-factor structure. Items loading on the first factor appeared to assess fitness and leisure activities, whereas those loading on the second and third factor assessed nutrition practices and stress control, respectively. A fourth factor assessed drinking/eating behaviors. Discriminant validity of the SHS was confirmed using the Instrumental Activities of Daily Living, and other health measures that indicated distinct constructs. Internal consistency for the SHS was .72 using Chronbach's alpha. Overall, the SHS Index displayed good psychometric properties in this sample, suggesting the appropriateness of using it to measure selected health behaviors with low SES older adults.     

Effects of reinforcer magnitude on responding under differential-reinforcement-of-low-rate schedules of rats and pigeons

Experiment I investigated the effects of reinforcer magnitude on differential-reinforcement-of-low-rate (DRL) schedule performance in three phases. In Phase 1, two groups of rats (n = 6 and 5) responded under a DRI. 72-s schedule with reinforcer magnitudes of either 30 or 300 microl of water. After acquisition, the water amounts were reversed for each rat. In Phase 2, the effects of the same reinforcer magnitudes on DRL 18-s schedule performance were examined across conditions. In Phase 3, each rat responded unider a DR1. 18-s schedule in which the water amotnts alternated between 30 and 300 microl daily. Throughout each phase of Experiment 1, the larger reinforcer magnitude resulted in higher response rates and lower reinforcement rates. The peak of the interresponse-time distributions was at a lower value tinder the larger reinforcer magnitude. In Experiment 2, 3 pigeons responded under a DRL 20-s schedule in which reinforcer magnitude (1-s or 6-s access to grain) varied iron session to session. Higher response rates and lower reinforcement rates occurred tinder the longer hopper duration. These results demonstrate that larger reinforcer magnitudes engender less efficient DRL schedule performance in both rats and pigeons, and when reinforcer magnitude was held constant between sessions or was varied daily. The present results are consistent with previous research demonstrating a decrease in efficiency as a function of increased reinforcer magnituide tinder procedures that require a period of time without a specified response. These findings also support the claim that DRI. schedule performance is not governed solely by a timing process.     

Getting a grip on the resilience to blur: The impact of simulated vision loss on a visually guided combat sports interaction

Research has shown that performance in highly visually demanding sports can be resilient to substantial levels of blur. This raises the question whether the need for high visual clarity might be reduced even more in less visually demanding sports such as combat sports, where athletes compete at relatively close distances. The aim of this study was to examine the resilience to blur in the grip fighting phase of judo as an exemplar of a visually guided combat sports task. The results were particularly relevant for the purposes of Paralympic judo for athletes with vision impairment (VI judo), because athletes are currently allowed to compete with a visual acuity (VA) of 1.0 logMAR or worse (i.e., 6/60 or 20/200 vision), suggesting this is the presumed level of impairment that decreases performance in able-sighted judo. We let 28 able-sighted judo athletes compete in pairs in a series of grip fighting tasks under increasing levels of simulated vision impairment. Visual function was tested in each condition by measuring VA and contrast sensitivity (CS). We found that VA was a better predictor than CS of grip fighting performance. VA needed to be reduced to at least 1.3 logMAR before a decrease in performance was found, with approximately twice as much blur needed to be applied when compared to visually demanding tasks such as cricket batting, but less than what has been found in static tasks such as basketball free-throw shooting and golf putting. These findings hold implications for VI judo regulations, suggesting that a more severe degree of impairment should be required to participate than is currently the case.     

Do we need visual subjects?

It is widely accepted within contemporary philosophy of perception that the content of visual states cannot be characterized simply as a list of represented features. This is because such characterization leads to the so-called ‘Many Properties’ problem, that is, it does not allow us to explain how the visual system is able to distinguish between scenes containing different arrangements of the same features. The usual solution to the Many Properties problem is to characterize some basic elements of content as subjects, to which features are attributed by a predication-like relation. In this paper, I reconsider this solution and claim that the Many Properties problem can be solved without postulating such subjects. What is more, I argue that an alternative approach has stronger justification given the empirical data concerning human vision.