That looks easy! Evidence against the benefits of an easier criterion of success for enhancing motor learning

OPTIMAL theory predicts providing learners with a relatively easier criterion of success during practice enhances motor learning through increased self-efficacy, perceptions of competence, and intrinsic motivation. However, mixed results in the literature suggest this enhancement effect may be moderated by the number of successes achieved by learners practicing with the difficult criterion. To investigate this possibility, we manipulated quantity of practice to affect the absolute number of successes achieved by learners practicing with different success criteria. Eighty participants were divided into four groups and performed 50 or 100 trials of a mini-shuffleboard task. Groups practiced with either a large or a small zone of success surrounding the target. Learning was assessed 24 h after acquisition with retention and transfer tests. In terms of endpoint accuracy and precision, there were no learning or practice performance benefits of practicing with an easier criterion of success, regardless of the number of trials. This absence of a criterion of success effect was despite the efficacy of our manipulation in increasing the number of trials stopping within the zone of success, self-efficacy, perceptions of competence, and, for participants with 100 trials, intrinsic motivation. An equivalence test indicated that the effect of criterion of success was small, if existent. Moreover, at the individual level, intrinsic motivation did not predict posttest or acquisition performance. There were no benefits of easing the criterion of success on pressure, effort, accrual of explicit knowledge, or conscious processing. These data challenge key tenets of OPTIMAL theory and question the efficacy of easing criterion of success for motor learning.     

Category size and judgments of variability: The effects of seeing the trees in the forest1

Abstract: Competing predictions about the effects of category size on judgments of category variability were examined in two studies involving the presentation of exemplars of two artificial social groups. In contrast to predictions of some exemplar-based models, Experiment 1 demonstrated that a numerically smaller group was perceived to be more variable than a larger group on the standard deviation measure of frequency distribution estimates. The result was interpreted to be an effect of differential information load. Experiment 2 revealed that variability judgments were influenced by prior expectations about the central tendencies as well as by practice in retrieving information about category exemplars. When frequency distribution estimates were made subsequent to abstract tasks, expectations about the numerical majority reduced perceived variability, while this influence was mitigated when memory measures preceded the frequency estimates.     

液晶显示器上字符辨认效果与观察角度及字符大小的关系

本研究从工程心理学角度,探讨了有源矩阵液晶显示器上字符辨认效果与观察角度及字符大小的关系。实验结果表明：(1)液晶显示的字符辨认效果因观察角度不同而存在显著差异,无论是在水平方向上还是下视方向上,字符辨认错误率均随着观察角度的增大而先慢后快地上升;但相比之下,水平方向上观察角度变化的容许范围大于下视方向上的容许范围;(2)液晶显示器上字符辨认效果也受字符大小的影响,并且字符大小与观察角度之间存在着显著的交互作用;当观察角度较大时,可通过加大字符尺寸来提高视觉辨认效果。     

Common mechanisms in apparent motion perception and visual pattern matching

There are close functional similarities between apparent motion perception and visual pattern matching. In particular, striking functional similarities have been demonstrated between perception of rigid objects in apparent motion and purely mental transformations of visual size and orientation used in comparisons of objects with respect to shape but regardless of size and orientation. In both cases, psychophysical data suggest that differences in visual size are resolved as differences in depth, such that transformation of size is done by translation in depth. Furthermore, the process of perceived or imagined translation appears to be stepwise additive such that a translation over a long distance consists of a sequence of smaller translations, the durations of these steps being additive. Both perceived and imagined rotation also appear to be stepwise additive, and combined transformations of size and orientation appear to be done by alternation of small steps of pure translation and small steps of pure rotation. The functional similarities suggest that common mechanisms underlie perception of apparent motion and purely mental transformations. In line with this suggestion, functional brain imaging has isolated neural structures in motion area MT used in mental transformation of size.     

Body image and size perceptions of Mexican American women

Purpose was to examine in Mexican American women the influences of age, weight, socioeconomic status and acculturation level on body image, perceptions of attractive and acceptable female shapes, and tolerance for overweight and obesity. Participants were 276 Mexican American women. Age, body mass index, socioeconomic status, and acculturation level were measured. The Figure Rating Scale was used to assess body image, preferences for body size, and perceptions of underweight to obese and acceptable body sizes. Significant effects for acculturation level and current weight were found. Women who were more Anglo oriented showed greater preference for thinner figures. As compared to normal weight women, obese women chose larger figures as ideal, realistic, attractive, and thinnest acceptable. Findings point to the impact of acculturation and obesity on body image and size perceptions. Health professionals working with Mexican Americans should consider each individual's current weight and level of acculturation.     

差数显著性t检验与元分析方法的模拟对比

利用计算机程序构造被试总体、模拟实验研究程序进行抽样研究 ,探讨差数显著性t检验方法与元分析方法在检验实验结果数据和进行实际应用方面的差异。模拟实验结果表明 ,差数显著性t检验与总体效果大小和样本容量有明显关系 ,但与随机抽样分布样本数目基本无关 ;抽样分布样本效果大小的平均值可以作为总体效果大小的估计值 ,它与样本容量和抽样样本数目有密切关系 ;本研究提供的实际应用数据结果可以作为研究者进行元分析方法实验研究的参考依据     

Visual body-size adaptation and estimation of tactile distance

Estimating the size of bodies is crucial for interactions with physical and social environments. Body-size perception is malleable and can be altered using visual adaptation paradigms. However, it is unclear whether such visual adaptation effects also transfer to other modalities and influence, for example, the perception of tactile distances. In this study, we employed a visual adaptation paradigm. Participants were exposed to images of expanded or contracted versions of self- or other-identity bodies. Before and after this adaptation, they were asked to manipulate the width of body stimuli to appear as ‘normal’ as possible. We replicated an effect of visual adaptation such that the body-size selected as most ‘normal’ was larger after exposure to expanded and thinner after exposure to contracted adaptation stimuli. In contrast, we did not find evidence that this adaptation effect transfers to distance estimates for paired tactile stimuli delivered to the abdomen. A Bayesian analysis showed that our data provide moderate evidence that there is no effect of visual body-size adaptation on the estimation of spatial parameters in a tactile task. This suggests that visual body-size adaptation effects do not transfer to somatosensory body-size representations.     

用层级相合性指标探测反应数据中噪音大小

不同的认知诊断模型（CDM）对反应数据中噪音的抗干扰能力不同,在评估CDM性能的模拟实验中,反应数据中所含噪音的大小是十分重要的实验条件。由于噪音的内隐性,为应用中选用相应的CDM带来困难。本文在认知模型已知条件下,欲使用MHCI和NHCI指标评估认知诊断测验的反应数据（0, 1评分）中噪音的大小。模拟实验表明,两指标与噪音存在明显的统计规律。尤其是以NHCI为主要自变量对噪音进行预测的回归方程中,回归模型解释率均接近90%;以此实现对噪音的有效预测,从而为选择CDM提供一个参考。     

Gradual increase of perturbation load induces a longer retention of locomotor adaptation in children with cerebral palsy

The goal of this study is to determine whether the size and the variability of error have an impact on the retention of locomotor adaptation in children with cerebral palsy (CP). Eleven children with CP, aged 7–16 years old, were recruited to participate in this study. Three types of force perturbations (i.e., abrupt, gradual and noisy loads) were applied to the right leg above the ankle starting from late stance to mid-swing in three test sessions while the subject walked on a treadmill. Spatial-temporal gait parameters were recorded using a custom designed 3D position sensor during treadmill walking. We observed that children with CP adapted to the resistance force perturbation and showed an aftereffect consisting of increased step length after load release. Further, we observed a longer retention of the aftereffect for the condition with a gradual load than that with an abrupt load. Results from this study suggested that the size of error might have an impact on the retention of motor adaptation in children with CP with a longer retention of motor adaptation for the condition with a small size of error than that with a large error. In addition, enhanced variability of error seems facilitate motor learning during treadmill training. Results from this study may be used for the development of force perturbation based training paradigms for improving walking function in children with CP.