时-空整合影响图形识别的眼动研究

采用眼动追踪的方法对在不同方向(上、下、左与右)及距离(2.0°‘和4.0°视角)上先后出现的特征组合不同的图形识别过程进行了研究。结果表明。首先,对由不同颜色和形状构成的图形的识别受到图形特征组合的影响,视觉系统对颜色和形状的加工存在明显差异,与颜色加工相比,视觉系统需要更多的时间才能完成形状识别。此外,虽然图形识别的速度和准确性受运动方向与距离的影响较小,但在不同运动方向和距离上,视觉系统是通过改变眼动的时间和空间特性来完成识别任务的,视觉系统在识别过程中的这种时间与空间的整合特点还有待于进一步研究。     

Precuing the Target Location in Visual Searching by a Chimpanzee (Pan troglodytes): Effects of Precue Validity

A chimpanzee ( Pan troglodytes ) performed a visual search task using a modified matching-to-sample procedure in which a sample stimulus was followed by the search display, which contained one stimulus identical to the sample (target) and several uniform stimuli different from the sample (distractors). On cued trials, while the subject was observing the sample, a white square (precue) appeared at the location where the target was to be presented (valid trials), or elsewhere (invalid trials). The validity of the precue (correspondence between the cued and the target locations) was changed from 0% to 100% across conditions. Cost-benefit analyses were performed on the difference between valid and noncued trials (benefit) and between invalid and noncued trials (cost). Under the high-validity conditions, the response times were shorter when the cued location corresponded to the target location than when the precue did not appear. When the cued location did not correspond to the target location, on the other hand, the subject took longer to select the target than on noncued trials. When the validity of the precue was relatively low, however, cost of the invalid trials disappeared, while benefit of the valid trials remained. These results confirmed the two-process (automatic and attentional) theory of priming in human information processing; the advance information had the same effects on a chimpanzee's visual search performance as on humans'.     

儿童运动视觉表象操作水平的发展及影响因素

采用计算机软件控制实验,以暴露运动一段行程后进入遮蔽的光点为刺激物,光点以三种不同运动速度、三种不同运动行距组合呈现,要求儿童判断光点到达目标位置时按键反应。结果表明：5—19岁儿童运动视觉表象操作水平的发展存在5一8岁、11—14岁两个加速期;客体运动速度对运动视觉表象操作绩效有显著影响,5、8、11岁组快速较中速下．5．8岁组中速较慢速下操作准确性均有显著降低;客体运动行距对运动视觉表象操作绩效也有显著的影响．5、8、11岁组右目标位置下较中目标位置下操作准确性显著降低;性别对运动视觉表象操作水平无显著影响。     

视觉选择过程中眼跳与注意关系的理论进展

视觉选择的过程包含两种途径:眼跳行动和注意转移,两者对于视觉选择目标物的加工都有促进作用。鉴于此,视觉研究领域产生大量关于二者关联如何的实验研究,大部分研究者认为眼跳和注意转移存在密切联系。该文将关于两者关系的重要理论进行了综合阐述和简要比较,主要介绍五种理论假说:眼动准备假说、动前假说、顺序注意模型、视觉注意模型和竞争整合模型。     

坡度知觉及其影响因素的研究进展

人们对于地表斜坡的知觉是非常不准确的,通常表现为对坡度估计过高。但是,研究发现,在以行为的方式对坡度进行模拟时,所模拟的坡度值却与实际坡度基本一致。这种面对同一视觉线索出现的视知觉与行为不一致的现象即为坡度知觉中的“知觉-行为分离”。本文回顾了影响坡度知觉的各种因素,涉及视觉线索、认知判断、感觉通道、生理状态以及报告方式等方面的研究,并对坡度知觉的未来研究进行了展望。     

Library Instruction,Intervention and Immersion: A 5-Year Study of Religion and the Arts

A religion faculty member approached the author after he gave a presentation to the faculty at Waldorf College on integrated library instruction. She expressed disappointment at her students’ scholarly performance on a major research paper she assigns every semester. The ensuing discussion resulted in a campus collaboration among the author, the faculty member, the campus writing center, and the academic achievement center. This article reports on the results of a five-year study on intervention and immersion of library instruction for the class Religion and the Arts at a small liberal arts college.     

Asymmetries in the Regulation of Visually Guided Aiming

An experiment was conducted to examine the contribution of sensory information to asymmetries in manual aiming. Movements were performed in four vision conditions. In the full-vision condition (FV), subjects were afforded vision of both the hand and the target throughout the course of the movement. In the ambient-illumination-off condition (AO), the room lights were extinguished at movement initiation, preventing vision of the moving limb. In the target-off (TO) condition, the target was extinguished upon initiation of the movement. In a no-vision (NV) condition, ambient illumination was removed and the target was extinguished upon initiation of the response movement. Results indicated that accuracy was superior in the full-vision and target-off conditions and when movements were made by the right hand. Movements made by the right hand were also of shorter mean duration. The magnitudes of performance asymmetries were uninfluenced by vision condition. Analyses of movement kinematics revealed that movements made in conditions in which there was vision of the limb exhibited a greater number of discrete modifications of the movement trajectory. On an individual-trial basis, no relationship existed between accuracy and the occurrence of discrete modifications. These data suggest that although vision greatly enhances accuracy, discrete modifications subserved by vision reflect the imposition of nonfunctional zero-order control processes upon continuous higher-order control regimes.     

Determinants of Offline Processing of Visual Information for the Control of Reaching Movements

The authors investigated the use of visual feedback as a form of knowledge of results (KR) for the control of rapid (200-250 ms) reaching movements in 40 participants. They compared endpoint accuracy and intraindividual variability of a full-vision group (FV) with those of no-vision groups provided with KR regarding (a) the endpoint in numerical form, (b) the endpoint in visual form, or (c) the endpoint and the trajectory in visual form (DEL). The FV group was more accurate and less variable than were the no-vision groups, and the analysis of limb trajectory variability indicated that their superior performance resulted primarily from better movement planning rather than from online visual processes. The FV group outperformed the DEL group even though both groups were obtaining the same amount of spatial visual information from every movement. That finding suggests that the effectiveness with which visual feedback is processed offline is not a simple function of the amount of visual information available, but depends on how that information is presented.