Intercepting Moving Objects During Self-Motion

It is generally assumed that in catching a fly ball, an efficient strategy for dealing with the horizontal component of the ball's trajectory is for the observer to keep the angular position of the ball constant with respect to his head. That strategy is called the constant bearing angle or CBA strategy. Maintenance of angular constancy results in the simultaneous arrival of both observer and ball at the landing spot. The authors analyzed the approach behavior of 26 subjects in a ball-interception task with straight paths for both the subjects and the ball. Subjects moved at a velocity that maintained a close-to-constant horizontal angular position of the ball with respect to the end effector throughout the approach phase rather than a constant bearing angle with respect to their head. Velocity adaptations occurred as a function of the changes in the angular velocity of the ball in such a way that a positive or negative angular velocity was canceled. Thus, an actor following the CBA strategy does not need to know where and when the ball will arrive (i.e., a predictive strategy), because reliance on the CBA strategy ensures that he will make the appropriate adaptations that enable him to arrive at the right place in the right time.     

Ethnicity and Social Support During Pregnancy

Data from two multi-ethnic prospective studies of African American, Latina, and non-Hispanic White pregnant women were used to examine the influence of contextual factors on social support processes during pregnancy. Multiple types of support (perceived support, received support, support satisfaction, network support) and sources of support (baby's father, family, friends) were assessed. The role of ethnicity in social support was examined after controlling for the contribution of related contextual factors (SES, marital status, age, parity, employment) to these processes. The impact of ethnicity and related contextual factors differed across sources of social support. Ethnic differences in support from family and friends, but not from the baby's father, emerged. However, marital status was a consistent predictor of support from the baby's father, and SES was a consistent predictor of support from friends. Overall, the findings of two studies suggest that although ethnicity is associated with support from friends and family, other contextual factors, such as marital status and SES, influence support processes during pregnancy.     

Cross-language positive priming disappears, negative priming does not: Evidence for two sources of selective inhibition

The authors used a unilingual and bilingual primed lexical decision task to investigate priming effects produced by attended and ignored words. In the unilingual experiment, accelerated lexical decisions to probe target words resulted when the word matched the preceding target word, whereas slowed lexical decisions to probe target words resulted when the word matched the preceding ignored nontarget word. In the bilingual (English-Spanish) experiment, between-language, rather than within-language, priming manipulations were used. Although the ignored repetition negative priming effect replicated across languages, cross-language attended repetition positive priming did not. This dissociation of priming effects in the inter- versus intralanguage priming conditions contradicts episodic retrieval accounts of negative priming that deny the existence of selective inhibitory processes. On the other hand, these results support an extension of inhibition-based accounts of negative priming, because they indicate that inhibition can operate at two levels of abstraction--local word and global language--simultaneously.     

儿童对抽象画情绪寓意理解的发展及文化因素的影响

本实验旨在探索儿童对抽象图画情绪寓意敏感性的发展规律以及文化因素的影响。被试年龄跨度从 5岁至高中学生。根据被试利用形态、主题、情绪等图片特性作为识辨依据的特点来发现规律。儿童对抽象图画寓意敏感性的发展与表征水平相关。年幼儿童只能利用颜色或图形等单一信息维量进行判断 ,年长儿童及中学生可以综合利用形态、主题、情绪等多个维量判断。在寓意明确的图片识辨中 ,儿童对积极寓意的识辨成绩较优。在双关寓意的图片识辨中 ,儿童组倾向于选择具有积极寓意的线索 ,而中学生组会受到识辨经验的影响。文化与教育方式影响儿童对抽象图画情绪寓意的理解。中国幼教方式有助于儿童对图画认知与情绪成分的识辨。     

Direct comparison of episodic encoding and retrieval of words: an event-related fMRI study

Functional magnetic resonance imaging (fMRI) was used to compare directly episodic encoding and retrieval. During encoding, subjects studied visually presented words and reported via keypress whether each word represented a pleasant or unpleasant concept (intentional, deep encoding). During the retrieval phase, subjects indicated (via keypress) whether visually presented words had previously been studied. No reliable differences were found during the recognition phase for words that had been previously studied and those that had not been studied. Areas preferentially active during encoding (relative to retrieval) included left superior frontal cortex, medial frontal cortex, left superior temporal cortex, posterior cingulate, left parahippocampal gyrus, and left inferior frontal gyrus. Regions more active in retrieval than encoding included bilateral inferior parietal cortex, bilateral precuneus, right frontal polar cortex, right dorsolateral prefrontal cortex, and right inferior frontal/insular cortex.     

Restricted attentional capacity between sensory modalities

The purpose of the experiments was to demonstrate an attentional-blink (AB) effect in a visual second task following the processing of a simple auditory signal. Subjects monitored a stream of letters presented at the middle of a computer screen using rapid serial visual presentation for the presence of a visual target (an X or a Y). In experimental trials, the visual target followed a pure tone that required an immediate speeded-choice response. When the tone had to be processed, accuracy in the visualencoding task suffered a marked and prolonged deficit that was timelocked to the onset of the tone. When the tone could be ignored or when no tone was presented, no deficit was observed in the visual task. The results demonstrate a cross-modal AB effect produced by a simple two-choice auditory discrimination task. The results are consistent with the view that at least part of the AB effect has a central, amodal, postperceptual locus.     

Dissociation between the effects of damage to perirhinal cortex and area TE

Perirhinal cortex and area TE are immediately adjacent to each other in the temporal lobe and reciprocally interconnected. These areas are thought to lie at the interface between visual perception and visual memory, but it has been unclear what their separate contributions might be. In three experiments, monkeys with bilateral lesions of the perirhinal cortex exhibited a different pattern of impairment than monkeys with bilateral lesions of area TE. In experiment 1, lesions of the perirhinal cortex produced a multimodal deficit in recognition memory (delayed nonmatching to sample), whereas lesions of area TE impaired performance only in the visual modality. In experiment 2, on a test of visual recognition memory (the visual paired comparison task) lesions of the perirhinal cortex impaired performance at long delays but spared performance at a very short delay. In contrast, lesions of area TE impaired performance even at the short delay. In experiment 3, lesions of the perirhinal cortex and lesions of area TE produced an opposite pattern of impairment on two visual discrimination tasks, simple object discrimination learning (impaired only by perirhinal lesions), and concurrent discrimination learning (impaired only by TE lesions). Taken together, the findings suggest that the perirhinal cortex, like other medial temporal lobe structures, is important for the formation of memory, whereas area TE is important for visual perceptual processing.     

Research misconduct—Have we reached the turning point at last?

The laissez-faire attitude towards dishonesty in research has simply created an environment for widespread escalation of the problem. Can we now believe anything we read? Why should we have confidence in an author because of his eminence? Should we automatically accept that clinical trials are always conducted with total integrity? Why have we been afraid to tackle this crisis head-on?     

解释学与自然科学:导论

２０世纪欧洲大陆思想发展过程中一直有一种最为怪癖的现象,就是对自然科学缺乏研究。的确,科学文献似乎否认哲学有超乎生活经验的立足点,并力求以这种方式采取一种客观陈述的姿态。分析的科学哲学采取了这种表面上有价值的姿态,并且以文化和历史要素相结合为代价而得以发展。分析的科学哲学家们把他们的工作看作是使自然科学的方法形式化,他们的兴趣不是专注于文化的、历史的和个人的因素能够成为决定因素的发现过程以及其他领域。然而,科学的知识也像一切知识一样,涉及对某人揭示（诉说）某事。科学探讨意义,这些意义就是体现在语…