Are there capacity limitations in symmetry perception?

Previous researchers have proposed that there are two types of symmetry detection: one based on crude preattentive symmetry judgments and another based on detailed scrutiny of individual parts (Barlow & Reeves, 1979; S. E. Palmer & Hemenway, 1978; Royer, 1981). Four experiments were conducted to examine capacity limits in different symmetry judgments. Observers were required to discriminate between random patterns and approximate symmetry (Experiments 1 and 3) or between perfect and approximate symmetry (Experiments 2 and 4). The patterns were divided into two sets of dots, presented either simultaneously or successively. A comparison of accuracy under these two presentation conditions suggested that symmetry detection involves an analysis that is spatially parallel but coarse, regardless of either task difficulty or task type (detecting symmetry vs. detecting asymmetry).     

Is there an assignment of top and bottom during symmetry perception?

We report data from a discrimination task in which participants had to decide whether a single-item display was either vertically symmetric or asymmetric. This decision was found to be easier when items with a top bottom polarity were placed in an orientation where the wide end was the base of the stimulus and the narrow end was the top. The difference in reaction times between this orientation and its inversion was about 10 ms. We suggest that top and bottom labels are assigned to stimuli during the detection of bilateral symmetry.     

Resiliency: A shift in our perception?

Abstract

As our clients often underestimate their own resources and potential, do helpers fall victim to the same phenomena? This article contends that helpers are often overly attentive to client deficits and pathology to the detriment of acknowledging family and other client strengths and resources brought into the therapeutic arena. Much of our professional training results in an overreliance upon pathological lenses which is to the disadvantage of both client and helper. Family therapists must remain vigilant to not becoming seduced into the attractive web of “pathologizing.” Experiences that heightened this awareness for the author are described, followed by illustration of the importance and benefit of therapists becoming more sensitive to the study of human resiliency.     

Is symmetry identity?

Wigner found unreasonable the "effectiveness of mathematics in the natural sciences". But if the mathematics we use to describe nature is simply a carefully coded expression of our experience then its effectiveness is quite reasonable. Its effectiveness is built into its design. We consider group theory, the logic of symmetry. We examine the premise that symmetry is identity; that group theory encodes our experience of identification. To decide whether group theory describes the world in such an elemental way we catalogue the detailed correspondence between elements of the physical world and elements of the formalism. Providing an unequivocal match between concept and mathematical statement completes the case. It makes effectiveness appear reasonable. The case that symmetry is identity is a strong one but it is not complete. The further validation required suggests that unexpected entities might be describable by the irreducible representations of group theory.     

Are there interactive processes in speech perception?

Lexical information facilitates speech perception, especially when sounds are ambiguous or degraded. The interactive approach to understanding this effect posits that this facilitation is accomplished through bi-directional flow of information, allowing lexical knowledge to influence pre-lexical processes. Alternative autonomous theories posit feed-forward processing with lexical influence restricted to post-perceptual decision processes. We review evidence supporting the prediction of interactive models that lexical influences can affect pre-lexical mechanisms, triggering compensation, adaptation and retuning of phonological processes generally taken to be pre-lexical. We argue that these and other findings point to interactive processing as a fundamental principle for perception of speech and other modalities.     

Action in perception? Empirical and philosophical arguments against the enactive approach to perception

This paper focuses on the epistemic conditions of visual perception, ie it concentrates on the question of what kind of knowledge is required for us in order to be able to see colours and shapes as spatial properties of things. According to contemporary theories of sensory perception that follow the tradition of George Berkeley, like Alva Noe's so-called enactive approach to perception, this type of visual perception requires a certain kind of implicit practical knowledge, namely implicit sensorimotor knowledge of the way sensory stimulation varies as the perceiver moves. Two objections are presented against this central claim of the enactive approach. First, empirical evidence from psychological research on children's cognitive and motor development suggests that visual content is entirely independent of sensorimotor knowledge. Second, the enactive approach gets involved in the characteristic problems of classical sense--datum theories by introducing the extremely problematic claim that the recognition of appearances is the epistemic starting point for the perception of things and their properties.     

Do objects in working memory compete with objects in perception?

It is generally assumed that “perceptual object” is the basic unit for processing visual information and that only a small number of objects can be either perceptually selected or encoded in working memory (WM) at one time. This raises the question whether the same resource is used when objects are selected and tracked as when they are held in WM. In two experiments, we measured dual-task interference between a memory task and a Multiple Object Tracking task. The WM tasks involve explicit, implicit, or no spatial processing. Our results suggest there is no resource competition between working memory and perceptual selection except when the WM task requires encoding spatial properties.     

Display-wide influences on figure–ground perception: The case of symmetry

Past research has demonstrated that convex regions are increasingly likely to be perceived as figures as the number of alternating convex and concave regions in test displays increases. This region-number effect depends on both a small preexisting preference for convex over concave objects and the presence of scene characteristics (i.e., uniform fill) that allow the integration of the concave regions into a background object/surface. These factors work together to enable the percept of convex objects in front of a background. We investigated whether region-number effects generalize to another property, symmetry, whose effectiveness as a figure property has been debated. Observers reported which regions they perceived as figures in black-and-white displays with alternating symmetric/asymmetric regions. In Experiments 1 and 2, the displays had articulated outer borders that preserved the symmetry/asymmetry of the outermost regions. Region-number effects were not observed, although symmetric regions were perceived as figures more often than chance. We hypothesized that the articulated outer borders prevented fitting a background interpretation to the asymmetric regions. In Experiment 3, we used straight-edge framelike outer borders and observed region-number effects for symmetry equivalent to those observed for convexity. These results (1) show that display-wide information affects figure assignment at a border, (2) extend the evidence indicating that the ability to fit background as well as foreground interpretations is critical in figure assignment, (3) reveal that symmetry and convexity are equally effective figure cues and, (4) demonstrate that symmetry serves as a figural property only when it is close to fixation.     

Can imagery facilitate improvements in anticipation behavior?

ObjectivesWe examined the effectiveness of interventions involving imagery, video, and outcome feedback in improving anticipation in skilled junior cricket batters.Design/methodParticipants (N = 34, Mean age = 14.9 years, SD = 0.75) were allocated to one of three groups matched on imagery ability or a no practice control. The experimental groups received a four-week, film-based training intervention.ResultsAll experimental groups improved anticipation performance during training. Pre to posttest improvements were greater for the group that received outcome Knowledge of Results (KR) compared to groups that also received a video replay of the bowler's action or imaged the previously seen action. All experimental groups improved visual imagery ability, measured by the VMIQ-2, but only the imagery intervention group improved in the kinesthetic dimension.ConclusionOur findings show that all three interventions are effective in improving anticipation and benefit imagery ability.     

Slowhand: Does time perception change in peri-hand space?

Psychonomic Bulletin & Review - A variety of attentional and perceptual changes occur in peri-hand space, including increases in visual temporal acuity. These changes in cognition have been...     

Statistical inference in behavior analysis: Environmental determinants?

Use of inferential statistics should be based on the experimental question, the nature of the design, and the nature of the data. A hallmark of single-subject designs is that such statistics should not be required to determine whether the data answer the experimental question. Yet inferential statistics are being included more often in papers that purport to present data relevant to the behavior of individual organisms. The reasons for this too often seem to be extrinsic to the experimental analysis of behavior. They include lapses in experimental design and social pressure from colleagues who are unfamiliar with single-subject research. Regardless of whether inferential statistics are used, behavior analysts need to be sophisticated about experimental design and inferential statistics. Such sophistication not only will enhance design and analysis of behavioral experiments, but also will make behavior analysts more persuasive in presenting rationales for the use or nonuse of inferential statistics to the larger scientific community.     

What mediates gender bias in work behavior ratings?

This study explored possible mediators of gender bias in work behavior ratings. However, we believed it important to do so by first attempting to create a decision-making environment that better reflected the cognitive demands imposed on raters in work settings. Accordingly, 74 participants, mostly White and middle class students, read a vignette that depicted the work behavior of a male or female police officer. All participants attended to another task while reading the vignette and did so while under a perceived time limit; then, immediately or 5 days later, they completed a work behavior questionnaire. As expected, more effective work behaviors were attributed to men than women—but only when ratings were delayed. Further analyses revealed that a systematic response bias was responsible, whereas selective memory played no role. Specifically, participants adopted a more liberal decision criterion when attributing effective work behaviors to men than women. These results help to illuminate the dynamics of discrimination and provide direction for future research efforts.     

What happened to analysis in applied behavior analysis?

This paper addresses the current help-oriented focus of researchers in applied behavior analysis. Evidence from a recent volume of JABA suggests that analytic behavior is at low levels in applied analysis while cure-help behavior is at high strength. This low proportion of scientific behavior is apparantly related to cure-help contingencies set by institutions and agencies of help and the editorial policies of JABA itself. These contingencies have favored the flight to real people and a concern with client gains, evaluation and outcome strategies rather than the analysis of contingencies of reinforcement controlling human behavior. In this regard, the paper documents the current separation of applied behavior analysis from the experimental analysis of behavior. There is limited use of basic principles in applied analysis today and almost no reference to the current research in the experimental analysis of behavior involving concurrent operants and adjunctive behavior. This divorce of applied behavior research and the experimental analysis of behavior will mitigate against progress toward a powerful technology of behavior. In order to encourage a return to analysis in applied research, there is a need to consider the objectives of applied behavior analysis. The original purpose of behavioral technology is examined and a re-definition of the concept of "social importance" is presented which can direct applied researchers toward an analytic focus. At the same time a change in the publication policies of applied journals such as JABA toward analytic research and the design of new educational contingencies for students will insure the survival of analysis in applied behavior analysis.