The role of attention in the facilitation effect and another "inhibition of return"

The present study investigated how anticipation of a target's appearance affects human attention to gaze cues provided by a schematic face. Subjects in a 'catch' group received a high number of 'catch' trials, in which no target stimulus appeared. Subjects in the control group did not receive any catch trials. As in previous studies, both groups showed a facilitation effect to the cued location during shorter stimulus onset asynchrony (SOA). In both groups, an analysis of eye movements confirmed that subjects' eyes remained on the fixation point, ruling out the possibility that the facilitation effect was due to shifting eye movements (saccades) as opposed to a shift in covert attention. But while the control group's response time (RT) decreased as SOA increased, the catch group's RT had a U-shaped pattern and the facilitation effect to the cued location was reversed at the longest SOA (1005 ms). These results suggest that subjects in the catch group disengaged their attention during long SOAs because they expected the trial to be a catch trial. This disengagement of attention during long SOAs results in a delay before attention could be re-focused to the previous location regardless of the cue validity ["IOR (inhibition of return)"-like-phenomenon]. Unlike the conventional IOR, we suggest that this "IOR"-like phenomenon caused by an unpredictive central gaze cue is likely to be mediated by an endogenous mechanism.     

Spatial representation of pitch height: the SMARC effect

Through the preferential pairing of response positions to pitch, here we show that the internal representation of pitch height is spatial in nature and affects performance, especially in musically trained participants, when response alternatives are either vertically or horizontally aligned. The finding that our cognitive system maps pitch height onto an internal representation of space, which in turn affects motor performance even when this perceptual attribute is irrelevant to the task, extends previous studies on auditory perception and suggests an interesting analogy between music perception and mathematical cognition. Both the basic elements of mathematical cognition (i.e. numbers) and the basic elements of musical cognition (i.e. pitches), appear to be mapped onto a mental spatial representation in a way that affects motor performance.     

Is motion extrapolation employed in multiple object tracking? Tracking as a low-level, non-predictive function

In a series of five experiments, we investigated whether visual tracking mechanisms utilize prediction when recovering multiple reappearing objects. When all objects abruptly disappeared and reappeared mid-trajectory, it was found that (a) subjects tracked better when objects reappeared at their loci of disappearance than when they reappeared in their extrapolated trajectories, (b) disappearance episodes ranging from 150 to 900 ms had virtually no differential effect on performance, (c) tracking deteriorated monotonically as a function of displacement magnitude during disappearance, and (d) tracking did not depend on whether objects moved in predictable paths. Even objects that reappeared backward in their trajectories were tracked dramatically better than objects that reappeared in their extrapolated trajectories. When all objects disappeared and reappeared in ways that implicated the presence of an occluder (i.e., with occlusion and disocclusion cues along fixed contours), tracking again was not predictive, and performance deteriorated with increased displacement. When objects reappeared predictably in 75% of trials, they were still tracked better when they reappeared at their points of disappearance. Theoretical implications of a non-predictive multiple object tracking mechanism are discussed.     

Implications of evidence-based practice for community health

Evidence-based practice, developed in clinical medicine, is being applied to community health programs. Barriers to implementation of evidence-based practice noted in clinical medicine are likely to exist in community health settings and may be complicated by the nature of community health programs. These barriers include accessibility and availability of relevant data, social and political considerations of program decision-making, and conflicting expectations for evaluation research. This paper discusses barriers to both amassing evidence for practice and using evidence for decision-making in community health. The potential for conflict between practice goals set by evidence-based thinking and those set by community health organizations is also discussed. Implications for evaluations of community health programs are raised and recommendations for improving access to and use of evaluation information are made.     

Critical issues in the prevention of violence-related behavior in youth

Violence prevention programs with varying degrees of scientific support have proliferated in the United States and elsewhere. This paper previewed a broad range of programs involving youth, families, or systems that aimed to prevent or reduce violence-related behavior. The purpose of the review was to address critical issues concerning (1) target level of programming, (2) theory-driven versus problem-driven conceptualization, (3) cultural considerations, (4) developmental considerations, (5) intervention fidelity, and (6) outcome and impact assessment. Conclusions about these issues address tendencies and trends across programs.     

A few minor suggestions.

We agree with almost all of the analysis in this excellent presentation of the molecular view of avoidance behavior. A few suggestions are made as follows: Referring to response-generated stimuli as 'readily observable" seems not quite right for the kinesthetic components of such stimuli, although their scientific legitimacy is not questioned. Interpreting response-generated stimuli as a form of positive reinforcement is contested, and an alternative interpretation is offered. A possibly simpler interpretation of the Sidman (1962) two-lever experiment is suggested. We question Dinsmoor's (2001) explanation for warning stimuli not being avoided, except for the reference to the weakness of third-order conditioning effects. A final question is raised regarding the nature of the variables that are responsible for the momentary evocation of the avoidance response.     

Illusory smoke and dazzling fog

It is well known that a flat ellipse rotating in the frontoparallel plane appears, after brief inspection, as a rigid circular disc tilting back and forth in a 3-D space. We here report that rotation of a grey-shaded ellipse on a white or on a black background produces the compelling illusion of a dark smoke or a dazzling fog (depending on the conditions of the background) moving in front of a completely white or completely black tilting disc. The fog effect disappears when there is a luminance contrast all along the perimeter of the ellipse. An experiment is reported showing that the effect can be experienced in static conditions only to a limited extent and mostly in the `dazzling' version, and that relative movement between the contours of the figure and the shaded area is crucial to the occurrence of the effect, while the occurrence of a depth effect is not. Received: 25 February 1999 / Accepted: 11 April 2000     

注意能力测评方法的初步研究

本研究自行开发了"BT-LYR注意能力测试软件(1.0版)",并发展了一套融专家经验与实际测试为一体的注意能力模糊综合评价方法.结果显示,注意能力测试软件及模糊综合评价方法都具有较高的信度和效度,值得在实践中进一步检验与推广.     

汉语句子可继续性对句子理解加工的即时影响

通过操纵动词与后接词的关系,来产生搭配异常并控制句子的可继续性,研究汉语词汇信息在句子加工中的即时作用。实验一利用跨通道技术,发现动一名词搭配异常对目标名词的加工有即时影响,形容词条件下可继续性对目标形容词的加工有即时影响;实验二采用眼动技术,发现名词条件和形容词条件下可继续性均有显著的即时影响。结果显示,语义等多种词汇信息被通达后立即共同参与了汉语句子加工。