Temporal aspects of slant and inclination perception.

Linear transformations (shear or scale transformations) of either horizontal or vertical disparity give rise to the percept of slant or inclination. It has been proposed that the percept of slant induced by vertical size disparity, known as Ogle's induced-size effect, and the analogous induced-shear effect, compensate for scale and shear distortions arising from aniseikonia, eccentric viewing, and cyclodisparity. We hypothesised that these linear transformations of vertical disparity are processed more slowly than equivalent transformations of horizontal disparity (horizontal shear and size disparity). We studied the temporal properties of the stereoscopic slant and inclination percepts that arose when subjects viewed stereograms with various combinations of horizontal and vertical size or shear disparities. We found no evidence to support our hypothesis. There were no clear differences in the build-up of percepts of slant or inclination induced by step changes in horizontal size or shear disparity and those induced by step changes in vertical size or shear disparity. Perceived slant and inclination decreased in a similar manner with increasing temporal frequency for modulations of transformations of both horizontal and vertical disparity. Considerable individual differences were found and several subjects experienced slant reversal, particularly with oscillating stimuli. An interesting finding was that perceived slant induced by modulations of dilation disparity was in the direction of the vertical component. This suggests the vertical size disparity mechanism has a higher temporal bandwidth than the horizontal size disparity mechanism. However, conflicting perspective information may play a dominant role in determining the temporal properties of perceived slant and inclination.     

团队权力分布差异对团队冲突的影响：程序公平和合法性的作用

近年来团队权力分布差异与团队冲突间关系受到了学界较大关注, 但相关研究结果仍存在分歧。通过对70个工作团队的调查, 探讨了团队权力分布差异对团队冲突(任务冲突、关系冲突)作用的边界条件。结果发现, 程序公平调节了两者间关系：当程序公平较高时, 团队权力分布差异与任务冲突、关系冲突负相关; 当程序公平较低时, 团队权力分布差异与任务冲突、关系冲突正相关。此外, 被中介的调节模型分析显示, 团队合法性感知中介了程序公平的上述调节作用。     

Dissociating the effects of angular disparity and image similarity in mental rotation and object recognition

Performance is often impaired linearly with increasing angular disparity between two objects in tasks that measure mental rotation or object recognition. But increased angular disparity is often accompanied by changes in the similarity between views of an object, confounding the impact of the two factors in these tasks. We examined separately the effects of angular disparity and image similarity on handedness (to test mental rotation) and identity (to test object recognition) judgments with 3-D novel objects. When similarity was approximately equated, an effect of angular disparity was only found for handedness but not identity judgments. With a fixed angular disparity, performance was better for similar than dissimilar image pairs in both tasks, with a larger effect for identity than handedness judgments. Our results suggest that mental rotation involves mental transformation procedures that depend on angular disparity, but that object recognition is predominately dependent on the similarity of image features.     

Relations of perceived ethnic disparity to involvement in ethnic and host cultures

Among 124 single foreign students residing in the USA, this study examined the relations between perceived ethnic disparity, consisting of physical, cultural. and linguistic dimensions, and ethnic and host culture involvement. The Ethnic Disparity Perception Inventory, a 44-item Likert scale devised to measure perceived ethnic disparity, showed perceived physical disparity (r = .60) and cultural disparity (r = .51) were positively related to ethnic involvement. Perceived cultural disparity (r = -.22) and linguistic disparity (r = -.27) were negatively associated with involvement in the host culture. Multiple regression analysis indicated that, although the findings held for non-White respondents, for White respondents (n = 39) perceived physical disparity (beta = .54), not cultural disparity, was a significant predictor of ethnic involvement (Adjusted R2 = .268) and perceived cultural disparity (beta = -.37), not linguistic disparity, was a significant (negative) indicator of host culture involvement (Adjusted R2 = .110).     

Perspective, orientation disparity, and anisotropy in stereoscopic slant perception.

Stereoscopic depth estimates are not predictable from the geometry of point disparities. The configural properties of surfaces (surface contours) may play an important role in determining, for example, slant responses to a disparity gradient, and the marked anisotropy in favour of slant around a horizontal axis. It has been argued that variation in slant magnitude are attributable to the degree of perspective conflict present and that anisotropy is attributable to orientation disparity, which varies with the axis of slant. Three experiments were conducted in which configural properties were varied to try and tease apart the respective roles of orientation disparity and conflicting perspective in determining stereoscopic slant perception and slant axis anisotropy. The results could not be accounted for by the magnitude of the orientation disparities present. Conflicting perspective cues appeared to play a role but only for slant around a vertical axis. It was concluded that there are important configural effects in stereopsis attributable neither to orientation disparity nor to perspective.     

Perception of depth: Different processing times for simple and relative positional disparity

Summary When judging in stereoscopic vision whether an object is lying in front of or behind the point of momentary fixation, the visual system extracts depth information by using retinal disparity; in this case it computes one angular difference between retinal images (simple positional disparity). But if the task is to discriminate two or more objects in their depth (relative to the point of fixation) and the relative distances between them, two or more such angular differences have to be determined (relative positional disparity). An investigation was carried out to determine whether depth extraction is more complex for relative distances than for object positions and therefore demands a longer processing time. For this purpose stimuli with simple and relative positional disparity were foveally and parafoveally presented (each followed by a masking stimulus). It was shown that the duration threshold for the detection of stimuli with relative disparity was about 2.5 times larger than that for stimuli with simple disparity (Exp. 1). This difference could not be attributed to differences in stimulus configuration between simple and relative disparity (Exp. 2). The results are discussed in terms of a serial, hierarchically structured, disparity processing.     

Perceptual learning without feedback and the stability of stereoscopic slant estimation

Subjects were examined for practice effects in a stereoscopic slant-estimation task involving surfaces that comprised a large portion of the visual field. In most subjects slant estimation was significantly affected by practice, but only when an isolated surface (an absolute disparity gradient) was present in the visual field. When a second, unslanted, surface was visible (providing a second disparity gradient and thereby also a relative disparity gradient) none of the subjects exhibited practice effects. Apparently, stereoscopic slant estimation is more robust or stable over time in the presence of a second surface than in its absence. In order to relate the practice effects, which occurred without feedback, to perceptual learning, results are interpreted within a cue-interaction framework. In this paradigm the contribution of a cue depends on its reliability. It is suggested that normally absolute disparity gradients contribute relatively little to perceived slant and that subjects learn to increase this contribution by utilizing proprioceptive information. It is argued that--given the limited computational power of the brain--a relatively small contribution of absolute disparity gradients in perceived slant enhances the stability of stereoscopic slant perception.     

Addictions Counseling Certification: An Emerging Counseling Specialty

This article summarizes the national standards for addictions counseling of 4 different professional groups or boards. The new addictions specialty certification standards that are being developed jointly by the National Board for Certified Counselors and the International Association of Addictions and Offender Counselors (a division of the American Counseling Association) are compared with the standards of 3 other groups.     

Self-image and Guilt: A Further Test of the Cognitive-Developmental Formulation

The cognitive-developmental formulation of self-image disparity holds that an increasing disparity between the real and ideal self-image is due to (a) increasing differentiation of the real from the ideal self with maturity and (b) the increased capacity for incorporation of social mores with a greater propensity for guilt as a result. Guilt and self-image disparity were assessed in 47 young adults in Study 1, and in 108 children, of varying intellectual abilities, in the 5th, 8th, and 11th grades in Study 2. In both studies, guilt was related to self-image disparity. At all age levels, guilt was related to a higher ideal self-image. Guilt was related to a higher real self-image among 5th graders, but not among older individuals. Brighter children had a higher ideal self-image, greater self-image disparity, and marginally more guilt than children of average intellectual abilities. Guilt and self-image disparity were not related to grade level. The pattern of findings indicated that self-image is influenced by both cognitive-developmental and experiential determinants.     

BRCA1 Testing: Genetic Counseling Protocol Development and Counseling Issues

This article discusses the genetic counseling protocols which were developed and counseling issues that have arisen in the first 2 years of evaluating a large kindred with a BRCA1 mutation. The rationale for the development of the genetic counseling protocols and specific genetic counseling visual aids are presented and discussed. The protocols and counseling aids can serve as models for other programs offering cancer susceptibility testing. The observations of study counselors about study subject concerns and responses to genetic testing at the time of the pretest and posttest counseling sessions are presented.     

Orientation disparity, deformation, and stereoscopic slant perception.

Koenderink and van Doorn's theory, that the basis of stereoscopic slant perception is the deformation component of the disparity, field, was tested for slant around a horizontal axis, which produces images with a vertical ramp of horizontal disparity (horizontal shear) characterised by a global orientation disparity at the vertical meridian. The disparity field in this case can be parsed into two components, deformation and curl, which each contribute half of the orientation disparity. This case was compared with similar random-dot stimuli in which the deformation component was doubled and the curl component eliminated or vice versa. All three types of stimuli had identical orientation disparity at the vertical meridian. A condition in which there was no such orientation disparity, but deformation was present, was also included. It was found that perceived slant was not related to the deformation present, as Koenderink and van Doorn's theory would predict, but was predictable from the orientation disparity at the vertical meridian per se.     

Sentencing Disparity: Perforce or Perchance?1

Important sources of variability in sentencing judgments are identified by decomposing these judgments in a Crime × Judge analysis of variance into a Crime main effect (representing consensus) and several forms of disparity. Two systematic forms of disparity are (1) the Judge main effect, reflecting differences in overall harshness or leniency of different judges; and (2) the Crime × Judge interaction, reflecting idiosyncracies—perhaps principled—in the way particular judges view particular crimes. A third unsystematic form of disparity is reflected in variations in how the same judge views the same crime/offender on different occasions, that is, unreliability. Data from an experiment in which state district judges made sentencing decisions about the same crime/offenders on two occasions are presented to illustrate application of the model and obtain disparity estimates for 13 crimes. Results reveal that for most of the crimes disparity can be attributed primarily to simple unreliability over occasions rather than principled disagreements among judges. Implications of these results and the importance of distinguishing different types of disparity are discussed.     

Ethics and Counseling Decisions

Although some behavioral scientists and practitioners contend that man has no genuine moral choices to make, common sense and philosophical reflection ineluctably affirm the moral nature of man. When young people are faced with moral decisions, they often seek the assistance of a counselor. Although such counselors are routinely expected to aid clients in making decisions about their education and their careers, there is considerably less agreement about their responsibility for helping students to make moral choices. The central thesis of this article is that a knowledge of ethical theories, the practical principles which flow from them, and the method of decision-making which they indicate will enable the counselor to assist his clients with their moral problems.     

Generic Models of Counseling Supervision: Counseling/Instruction Dichotomy and Consultation Metamodel

Major conceptual models for counseling supervision are described and compared: supervision as a counseling analog, as an instruction or teaching analog, and as a role that includes counseling and teaching aspects. Although each of these approaches avails supervisors of familiar roles, none adequately provides the scope and utility required of a model for such a complex function. Thus, a higher order metamodal, supervision as consultation, is presented, and this consultation metamodel is related to the psychoeducational model for counseling psychology.     

Effects of response disparity on stimulus and reinforcer control in human detection tasks

In two detection experiments, university students reported whether the second of two sequentially presented tones was longer or shorter than the first by responding to stimuli presented on a touch screen. Stimulus disparity and response disparity were manipulated to compare their effects on measures of discrimination and response bias when the reinforcement ratio for correct responses was asymmetric. Choice stimuli consisted of squares filled with different pixel densities. Response disparity was manipulated by varying the difference in density between the two choice stimuli. In both experiments, decreasing stimulus disparity reduced discrimination but had no consistent effect on bias. Decreasing response disparity also reduced discrimination in both experiments, and often reduced estimates of bias. The effects of response disparity on bias were most clear in Experiment 2, in which a greater overall level of response disparity was arranged. The data show that, like corresponding research with pigeons, detection performance of human subjects can be conceptualized as discriminated operants.     

Combining binocular and monocular curvature features.

A study is reported of the perception of visual surfaces in wire-frame stimuli generated by combinations of monocular surface contours and binocular disparity that provide differing information about 3-D relief. Observers vary considerably in the relative contribution made by the binocular and monocular cues to the perception of overall 3-D form. Without training, many observers may entirely fail to perceive surface curvature from the binocular disparity patterns, interpreting the form of the surface only according to the monocular information. For other observers, both cues contribute to the end percept, with the monocular interpretation dominating where the disparity information indicates planarity and with disparity dominating where disparity information suggests curvature and the monocular interpretation suggests planarity. Where stereo and monocular interpretations indicate inconsistent surface curvature features at a common location, more complex resolution strategies are suggested.     

Independent effects of local and global binocular disparity on the perceived convexity of stereoscopically presented faces in scenes

Evidence suggests that experiencing the hollow-face illusion involves perceptual reversal of the binocular disparities associated with the face even though the rest of the scene appears unchanged. This suggests stereoscopic processing of object shape may be independent of scene-based processing of the layout of objects in depth. We investigated the effects of global scene-based and local object-based disparity on the compellingness of the perceived convexity of the face. We took stereoscopic photographs of people in scenes, and independently reversed the binocular disparities associated with the head and scene. Participants rated perceived convexity of a natural disparity ("convex") or reversed disparity ("concave") face shown either in its original context with reversed or natural disparities or against a black background. Faces with natural disparity were rated as more convincingly convex independent of the background, showing that the local disparities can affect perceived convexity independent of disparities across the rest of the image. However, the apparent convexity of the faces was also greater in natural disparity scenes compared to either a reversed disparity scene or a zero disparity black background. This independent effect of natural scene disparity suggests that the 'solidity' associated with natural scene disparities spread to enhance the perceived convexity of the face itself. Together, these findings suggest that global and local disparity exert independent and additive effects upon the perceived convexity of the face.     

Vertical disparity affects shape and size judgments across surfaces separated in depth

Vertical binocular disparity provides a useful source of information allowing three-dimensional (3-D) shape to be recovered from horizontal binocular disparity. In order to influence metric shape judgments, a large field of view is required, suggesting that vertical disparity may play a limited role in the perception of objects projecting small retinal images. This limitation could be overcome if vertical disparity information could be pooled over wide areas of 3-D space. This was investigated by assessing the effect of vertical disparity scaling of a large surround surface on the perceived size and 3-D shape of a small, central object. Observers adjusted the size and shape of a virtual, binocularly defined ellipsoid to match those of a real, hand-held tennis ball. The virtual ball was presented at three distances (200, 325, and 450 mm). Vertical disparities in a large surround surface were manipulated to be consistent with a distance of 160 mm or infinity. Both shape and size settings were influenced by this manipulation. This effect did not depend on presenting the surround and target objects at the same distance. These results suggest that the influence of vertical disparity on the perceived distance to a surface also affects the estimated distance of other visible surfaces. Vertical disparities are therefore important in the perception of metric depth, even for objects that in themselves subtend only small retinal images.     

Integration of disparity and velocity information for haptic and perceptual judgments of object depth

Do reach-to-grasp (prehension) movements require a metric representation of three-dimensional (3D) layouts and objects? We propose a model relying only on direct sensory information to account for the planning and execution of prehension movements in the absence of haptic feedback and when the hand is not visible. In the present investigation, we isolate relative motion and binocular disparity information from other depth cues and we study their efficacy for reach-to-grasp movements and visual judgments. We show that (i) the amplitude of the grasp increases when relative motion is added to binocular disparity information, even if depth from disparity information is already veridical, and (ii) similar distortions of derived depth are found for haptic tasks and perceptual judgments. With a quantitative test, we demonstrate that our results are consistent with the Intrinsic Constraint model and do not require 3D metric inferences (Domini, Caudek, & Tassinari, 2006). By contrast, the linear cue integration model (Landy, Maloney, Johnston, & Young, 1995) cannot explain the present results, even if the flatness cues are taken into account.     

Aftereffects and the representation of stereoscopic surfaces

The structure of human disparity representation is examined through (i) adaptation experiments and (ii) model simulations of the data. Section 3 presents results of adaptation experiments designed to illuminate the structure of human disparity representation. Section 4 presents model simulations of three different disparity representation schemes. In the experiments, participants adapted to a 0.133 cycle deg-1 sinusoidally corrugated surface with 10 min of arc peak-to-trough disparity. A flat test surface was briefly presented, in which the aftereffect surface was perceived. Adapt and test surfaces were placed on disparity pedestals and thus presented in front of or behind the plane of fixation. The adapt surface could be offset from the fixation plane by +/- 8 to 24 min of arc. The test surface could be offset from the fixation plane by +/- 8 to 48 min of arc. The depth aftereffect was measured in different disparity planes by a nulling method and 'topping-up' procedure. Aftereffect tuning functions were obtained whose bandwidths, magnitudes, and tuning depended on the disparity planes of both the adapt and test surfaces. These parameters were used to constrain the models tested in section 4. On the basis of the two studies, it is argued that the human stereoscopic system encodes spatial changes of disparity using channels localised within disparity planes. A localised disparity-gradient model of the human representation of disparity is proposed.