伸手拦截启动中的信息利用

通过两项实验考察时空信息对拦截运动启动的影响: 实验一为知觉估计实验, 通过释放匀速小球模拟拦截过程; 实验二为特定拦截路线情景下的拦截行为实验, 即固定手的拦截方向, 但容许拦截速度自由控制。结果发现, 拦截行为的启动基于综合信息, 在所拦截物体作慢速运动的情景下拦截行为启动偏早, 而在快速运动的情景下启动偏晚, 结果不支持单纯用tau理论解释启动行为。本研究对手的速度伴随效应提出了新的解释。     

自由拦截启动策略与信息利用

手的启动方向自由, 伸手拦截不同速度的运动小球。本研究通过考察手启动时的运动参数, 研究自由启动的情况下的信息利用和拦截策略, 并且考察了人的启动模式。结果发现, 自由拦截时手的拦截区域相对固定, 在物体快速运动情景下启动晚, 而在慢速下启动早, 可能综合利用了接触时间和距离信息, 存在速度伴随效应, 手的拦截启动策略为启动有相对稳定的角度和加速度, 并不随物体运动速度和物体大小的改变而改变。     

时间和空间信息在不同伸手拦截阶段的利用

探讨时间和空间信息在不同伸手拦截运动阶段中的作用。利用遮挡和干扰的手段,通过考察在排除某种信息后的情况,分析其该信息对伸手拦截运动参数的影响。结果发现:空间信息主要作用于早期,缺乏空间信息时手的最大速度显著减小;时间信息在整个拦截过程中均起作用,干扰早期和中期的时间信息将使达到最大速度的时间推后。结果不支持现有的伸手拦截模型,但与"计划控制模型"相符。     

三维虚拟空间中转头选中远离和靠近运动目标的操作特性差异

通过转头选中运动目标是虚拟现实(VR)中的常见操作,然而运动目标包含远离和靠近运动,确定两类操作的时间特性差异对设计高效的用户接口有重要的意义。本研究选取17名被试在VR中通过转头将球体光标快速准确地放入水平运动的球体目标内,并改变初始距离、目标容差和目标速度。总时间结果显示,远离运动的操作难度更大,初始距离和目标容差对远离和靠近运动的影响相似,目标速度对两类运动的影响相反。进一步将光标的移动过程划分为加速、减速和调整阶段,结果发现,远离运动的加速和减速时间大于靠近运动,但是两类运动的调整时间接近,并且只有目标容差对两类运动的影响一致。最后构建了总时间与三因素的函数模型,成功解释了两类运动的操作时间特性。本研究证明了远离与靠近运动具有不同的操作时间特性,为两类运动的独立交互设计提供了重要参考。     

视觉搜索中多目标追踪的研究

在视觉信息的选择加工过程中 ,只有很少信息能够通过注意系统得到进一步的认知加工 ,其中视觉搜索起着十分重要的作用。本研究基于动态视觉信息注意追踪的研究 ,采用 3× 2× 2的实验设计 ,从如下三方面对注意追踪的规律进行了探讨 :(1)分心物数量 (1,5和 9)的变化对多目标注意追踪的影响 ;(2 )目标的显著性 (特征变化和特征不变 )对多目标注意追踪的影响 ;(3)目标运动形式 (目标随机运动和目标运动形式不变 )对多目标注意追踪的影响。研究结果表明 :(1)分心物数量的增加对目标的注意识别没有抑制作用 ;(2 )特征变化目标的注意识别速度显著高于特征不变的目标 ;(3)运动形式不变的目标较运动形式变化目标的注意识别速度快。     

视觉注意选择性的空间位置效应的研究

采用注意线索技术探讨颜色、角度和空间位置对视觉选择性注意的影响。研究结果表明 :( 1 )目标与干扰刺激颜色相同时 ,表现出明显的注意空间位置效应 ;( 2 )目标与干扰刺激颜色不同时 ,空间位置效应明显弱化 ;( 3 )整体而言 ,注意加工速度从左到右均表现出明显的“V”字形效应。     

平滑运动条件下的图形颜色及形状加工特性的研究

本研究对在运动图形识别过程中,有关图形的不同特征（颜色、形状等）的加工特性、方向性效应以及不同空间位置（或时间间隔）对图形识别的影响了探讨。结果发现,视觉系统在运动信息加工时,对目标的不同特征的加工存在不均衡性,加工的难度有差异。颜色的加工难度要比形状的加工难度小。视觉系统对不同运动方向上的图形匹配反应特性也存在差异,图形匹配过程受时间或距离因素的影响,匹配的反应时随着两个比较图形之间的空间距离的增加而减少。     

多目标追踪中基于运动信息的分组效应

本研究旨在探讨运动信息对多目标追踪的影响, 具体为考察多目标追踪中是否存在基于运动信息的分组效应, 以及不同类型表面特征(颜色和形状)对这一效应的影响。实验1发现多目标追踪中存在基于运动信息的分组效应, 并且这一分组效应是自动化的。实验2和实验3分别在不同颜色和不同形状组合条件下考察了基于运动信息的分组效应的稳定性, 结果都表明不同表面特征的组合不会干扰基于运动信息的分组效应的形成, 但其效应量都因表面特征的出现而缩减。整体而言, 多目标追踪中存在基于运动信息的自动化分组效应, 并且这一效应是格式塔法则中共同命运律的具体表现, 能稳定存在于不同表面特征组合之间。     

眼睛注视的知觉及其线索效应

对眼睛注视知觉、眼睛注视线索效应及其影响因素等相关研究进行了总结和分析。结果发现:(1)婴儿从一出生就对眼睛注视线索表现出强烈的敏感性,眼睛注视知觉对语言和社会等能力的发展有很大影响;(2)颞上沟是加工眼睛注视线索的特异神经结构,它与实时监控情绪和情感的杏仁核存在神经联结,成为社会认知神经系统的重要组成部分;(3)对眼睛注视线索的早期加工显示出特异的脑电活动模式;(4)眼睛注视线索效应与外周线索的反射式效应相类似,但持续时间较长;(5)眼睛注视线索效应不仅受面部结构信息的影响,也受自上而下加工等高水平认知因素的调节,并显示出明显的个体差异。对眼睛注视线索效应的进一步研究应涉及人格判断、喜好评价和心理理论等高级社会认知活动。     

刺激持续时间对注意瞬脱影响的实验分离现象

通过三个实验,研究了注意瞬脱效应以便深入理解注意时间维度上的特性。实验一针对注意瞬脱效应（简称AB效应）和刺激持续显示时间（简称ED）之间的关系,发现SOA或者ED的延长能减小AB效应。实验二的结果再次证明ED的延长能减小AB效应,并且发现ED延长并没有伴随着对目标的加工速度的加快。实验三发现在目标与干扰项没有显著的特征差异时,AB效应随着ED延长而减小的现象消失了,即ED对AB效应的影响出现了实验性的分离。同时还证明突出显示可以通过加快对目标的反应速度来显著的减小AB效应,而且ED因素只有在目标具有突出的视觉特征时才能改变AB效应。     

Systematic variation in performance of an interceptive action with changes in the temporal constraints.

People are highly skilled at intercepting moving objects and are capable of remarkably accurate timing. The timing accuracy required depends upon the period of time for which contact with a moving target is possible--the "time window" for successful interception. Studies of performance in an experimental interception task that allows this time window to be manipulated suggest that people change aspects of their performance (movement time, MT, and movement speed) in response to changes in the time window. However, this research did not establish whether the observed changes in performance were the results of a response to the time window per se or of independent responses to the quantities defining the time window (the size and speed of a moving target). Experiment 1 was designed to resolve this issue. The speed and size of the target were both varied, resulting in variations in the time window; MT was the primary dependent measure. Predictions of the hypothesis that people respond directly to changes in the time window were verified. Predictions of the alternative hypothesis that responses to changes in target speed and size are independent of one another were not supported. Experiment 2 examined how the type of performance change observed in Experiment 1 was affected by changing the time available for executing the interception. The time available and the target speed were varied, and MT was again the primary dependent measure. MT was smaller when there was less time available, and the effect of target speed (and hence the time window) on MT was also smaller, becoming undetectable at the shortest available time (0.4 s). The results of the two experiments are interpreted as providing information about the "rule" used to preprogramme movement parameters in anticipatory interceptive actions.     

Visual guidance of intercepting a moving target on foot

How do people walk to a moving target, and what visual information do they use to do so? Under a pursuit strategy, one would head toward the target's current position, whereas under an interception strategy, one would lead the target, ideally by maintaining a constant target-heading angle (or constant bearing angle). Either strategy may be guided by the egocentric direction of the target, local optic flow from the target, or global optic flow from the background. In four experiments, participants walked through a virtual environment to reach a target moving at a constant velocity. Regardless of the initial conditions, they walked ahead of the target for most of a trial at a fairly constant speed, consistent with an interception strategy (experiment 1). This behavior can be explained by trying to maintain a constant target-heading angle while trying to walk a straight path, with transient steering dynamics. In contrast to previous results for stationary targets, manipulation of the local optic flow from the target (experiment 2) and the global optic flow of the background (experiments 3 and 4) failed to influence interception behavior. Relative motion between the target and the background did affect the path slightly, presumably owing to its effect on perceived target motion. We conclude that humans use an interception strategy based on the egocentric direction of a moving target.     

Synchronizing self and object movement: how child and adult cyclists intercept moving gaps in a virtual environment

Two experiments examined how 10- and 12-year-old children and adults intercept moving gaps while bicycling in an immersive virtual environment. Participants rode an actual bicycle along a virtual roadway. At 12 test intersections, participants attempted to pass through a gap between 2 moving, car-sized blocks without stopping. The blocks were timed such that it was sometimes necessary for participants to adjust their speed in order to pass through the gap. We manipulated available visual information by presenting the target blocks in isolation in Experiment 1 and in streams of blocks in Experiment 2. In both experiments, adults had more time to spare than did children. Both groups had more time to spare when they were required to slow down than when they were required to speed up. Participants' behavior revealed a multistage interception strategy that cannot be explained by the use of a monotonic control law such as the constant bearing angle strategy. The General Discussion section focuses on possible sources of changes in perception-action coupling over development and on task-specific constraints that could underlie the observed interception strategy.     

Indirect interception actions by blind and sighted perceivers: The role of modality and tau

Vernat, J.‐P. & Gordon, M.S. (2011). Indirect interception actions by blind and sighted perceivers: The role of modality and tau. Scandinavian Journal of Psychology 52, 83–92. Acoustic and visual interceptive actions were tested in this research by comparing the performance of blind, blind‐folded, and sighted individuals. An indirect interception method was employed in which the participant had to roll an intercepting ball towards a moving target on a perpendicular track. The interception task used conditions that varied the speed, rolling distance, and target size/intensity. While performance was highly consistent and accurate for visual participants in this research, the blind and blind‐folded participants demonstrated much more performance variability in response to changes in speed and distance. Manipulation of target size and intensity did not affect judgments, however performance tended to be more accurate at shorter distances and with faster target speeds. Results from this research are discussed in terms of their implications for tau in acoustic interception, and the use of spatial and temporal cues for guiding interceptive actions.     

Control strategies when intercepting slowly moving targets

In 3 experiments, the authors investigated and described how individuals control manual interceptive movements to slowly moving targets. Participants (N = 8 in each experiment) used a computer mouse and a graphics tablet assembly to manually intercept targets moving across a computer screen toward a marked target zone. They moved the cursor so that it would arrive in the target zone simultaneously with the target. In Experiment 1, there was a range of target velocities, including some very slow targets. In Experiment 2, there were 2 movement distance conditions. Participants moved the cursor either the same distance as the target or twice as far. For both experiments, hand speed was found to be related to target speed, even for the very slowly moving targets and when the target-to-cursor distance ratios were altered, suggesting that participants may have used a strategy similar to tracking. To test that notion, in Experiment 3, the authors added a tracking task in which the participants tracked the target cursor into the target zone. Longer time was spent planning the interception movements; however, there was a longer time in deceleration for the tracking movements, suggesting that more visually guided trajectory updates were made in that condition. Thus, although participants scaled their interception movements to the cursor speed, they were using a different strategy than they used in tracking. It is proposed that during target interception, anticipatory mechanisms are used rather than the visual feedback mechanism used when tracking and when pointing to stationary targets.     

Indirect interception actions by blind and visually impaired perceivers: Echolocation for interceptive actions

Vernat, J.-P. & Gordon, M. S. (2010). Indirect interception actions by blind and visually impaired perceivers: Echolocation for interceptive actions. Scandinavian Journal of Psychology, 51, 75–83.
This research examined the acoustic information used to support interceptive actions by the blind. Congenitally blind and severely visually impaired participants (all wearing an opaque, black eye-mask) were asked to listen to a target ball rolling down a track. In response, participants rolled their own ball along a perpendicular path to intercept the target. To better understand what information was used the echoic conditions and rolling dynamics of the target were varied across test sessions. In addition the rolling speed of the target and the distance of the participant from the target were varied across trials. Results demonstrated that participants tended to perform most accurately at moderate speeds and distances, overestimating the target's arrival at the fastest speed, and underestimating it at the slowest speed. However, changes to the target's dynamics, that is, the amount of deceleration it underwent on approach, did not strongly influence performance. Echoic conditions were found to affect performance, as participants were slightly more accurate in conditions with faster, higher-intensity echoes. Based on these results blind individuals in this research seemed to be using spatial and temporal cues to coordinate their interceptive actions.     

Development of interception of moving targets by chimpanzees (<Emphasis Type="Italic">Pan troglodytes</Emphasis>) in an automated task

The experiments investigated how two adult captive chimpanzees learned to navigate in an automated interception task. They had to capture a visual target that moved predictably on a touch monitor. The aim of the study was to determine the learning stages that led to an efficient strategy of intercepting the target. The chimpanzees had prior training in moving a finger on a touch monitor and were exposed to the interception task without any explicit training. With a finger the subject could move a small "ball" at any speed on the screen toward a visual target that moved at a fixed speed either back and forth in a linear path or around the edge of the screen in a rectangular pattern. Initial ball and target locations varied from trial to trial. The subjects received a small fruit reinforcement when they hit the target with the ball. The speed of target movement was increased across training stages up to 38 cm/s. Learning progressed from merely chasing the target to intercepting the target by moving the ball to a point on the screen that coincided with arrival of the target at that point. Performance improvement consisted of reduction in redundancy of the movement path and reduction in the time to target interception. Analysis of the finger's movement path showed that the subjects anticipated the target's movement even before it began to move. Thus, the subjects learned to use the target's initial resting location at trial onset as a predictive signal for where the target would later be when it began moving. During probe trials, where the target unpredictably remained stationary throughout the trial, the subjects first moved the ball in anticipation of expected target movement and then corrected the movement to steer the ball to the resting target. Anticipatory ball movement in probe trials with novel ball and target locations (tested for one subject) showed generalized interception beyond the trained ball and target locations. The experiments illustrate in a laboratory setting the development of a highly complex and adaptive motor performance that resembles navigational skills seen in natural settings where predators intercept the path of moving prey. Electronic Supplementary Material Supplementary material is available for this article if you access the article at . A link in the frame on the left on that page takes you directly to the supplementary material.     

How dogs navigate to catch frisbees

Using micro-video cameras attached to the heads of 2 dogs, we examined their optical behavior while catching Frisbees. Our findings reveal that dogs use the same viewer-based navigational heuristics previously found with baseball players (i.e., maintaining the target along a linear optical trajectory, LOT, with optical speed constancy). On trials in which the Frisbee dramatically changed direction, the dog maintained an LOT with speed constancy until it apparently could no longer do so and then simply established a new LOT and optical speed until interception. This work demonstrates the use of simple control mechanisms that utilize invariant geometric properties to accomplish interceptive tasks. It confirms a common interception strategy that extends both across species and to complex target trajectories.