Double fusion does not occur in Panum's limiting case: evidence from orientation disparity.

When two lines of different orientations are combined in regular stereograms, the orientation of the resulting line is different from those of the monocular lines. In this study we investigate the percept elicited by orientation disparity in Panum's limiting case. A variant of Panum's limiting case was designed to include orientation disparity. The single line in one half-image tilted leftwards. One of the double lines in the other half-image was parallel to the single line, while the other one tilted rightwards with obliquity one third that of the single line. In this stimulus configuration, if the single line in one half-image fuses with both lines in the other half-image at the same time, both of the two lines perceived after fusion should tilt leftwards. If double fusion does not happen, the two lines should tilt leftwards and rightwards respectively. The results of this study are in agreement with the latter prediction, which implies that double fusion does not occur in this variant of Panum's limiting case.     

Monocular discs in the occlusion zones of binocular surfaces do not have quantitative depth--a comparison with Panum's limiting case

Da Vinci stereopsis is defined as apparent depth seen in a monocular object laterally adjacent to a binocular surface in a position consistent with its occlusion by the other eye. It is widely regarded as a new form of quantitative stereopsis because the depth seen is quantitatively related to the lateral separation of the monocular element and the binocular surface (Nakayama and Shimojo 1990 Vision Research 30 1811-1825). This can be predicted on the basis that the more separated the monocular element is from the surface the greater its minimum depth behind the surface would have to be to account for its monocular occlusion. Supporting evidence, however, has used narrow bars as the monocular elements, raising the possibility that quantitative depth as a function of separation could be attributable to Panum's limiting case (double fusion) rather than to a new form of stereopsis. We compared the depth performance of monocular objects fusible with the edge of the surface in the contralateral eye (lines) and non-fusible objects (disks) and found that, although the fusible objects showed highly quantitative depth, the disks did not, appearing behind the surface to the same degree at all separations from it. These findings indicate that, although there is a crude sense of depth for discrete monocular objects placed in a valid position for uniocular occlusion, depth is not quantitative. They also indicate that Panum's limiting case is not, as has sometimes been claimed, itself a case of da Vinci stereopsis since fusibility is a critical factor for seeing quantitative depth in discrete monocular objects relative to a binocular surface.     

Occlusion as a depth cue in the Wheatstone-Panum limiting case.

We examined the hypothesis (Ono & Wade, 1985) that occlusion of far stimuli by a near one on the same visual line can operate as a depth cue in stereograms containing different numbers of targets in the two eyes. By controlling eye positions, we created conditions in which the visual system could interpret the retinal images as originating from stimuli on the visual axis of one eye and also created other conditions in which the origin of the retinal images was ambiguous. In Experiment 1, we presented two lines to one eye and a single line to the other eye. When the image of the line on the temporal side of the line pair on one retina fused with the image of the single line on the other retina, the nonfused line appeared farther away more often than it did when the image on the nasal side fused. In Experiment 2, we used two differently shaped stimuli. In the condition in which the nonfused stimulus represented an object being occluded, it appeared farther away more often than in the four conditions in which it did not. In Experiment 3, we extended the idea to three different objects. When the middle of the three images fused with the single image, the nonfused stimulus appeared farther when it could be interpreted as being occluded than when it could not. In the condition in which the most temporal image fused with the single image, the nonfused stimuli appeared farther than in the condition in which the most nasal one fused. The results supported the hypothesis that occlusion plays a role in depth perception in the Wheatstone-Panum limiting case.     

Blood donation and the foot-in-the-door technique: a limiting case.

Three experiments testing the effectiveness of the foot-in-the-door technique for recruiting blood donors consistently failed to demonstrate that this procedure influences either verbal or behavioral compliance, suggesting that the generality of the foot-in-the-door phenomenon is limited. Experiment 1 attempted to demonstrate that an earlier failure of this technique was due to poor operationalization rather than to the magnitude of the critical request or to the invalidity of the phenomenon, but it failed to do so. Experiment 2, designed to more closely resemble other foot-in-the-door studies by using telephone contacts and an initial request for persons to answer questions, was conducted to examine other possible explanations for the two previous failures. This experiment also failed to show any foot-in-the-door effect. Experiment 3 was a conceptual replication of Experiment 2 but used personal contacts. One apparent foot-in-the-door effect emerged in this case, but it was more likely due to a factor other than the experimental treatment. It is concluded that although the foot-in-the-door procedure may indeed influence verbal compliance with requests for minimal forms of aid, it probably will not significantly affect people's willingness to comply with more substantial requests involving behaviors that are psychologically costly to perform.     

Wheatstone-Panum limiting case: occlusion, camouflage, and vergence-induced disparity cues.

We examined effects of binocular occlusion, binocular camouflage, and vergence-induced disparity cues on the perceived depth between two objects when two stimuli are presented to one eye and a single stimulus to the other (Wheatstone-Panum limiting case). The perceived order and magnitude of the depth were examined in two experimental conditions: (1) The stimulus was presented on the temporal side (occlusion condition) and (2) the nasal side (camouflage condition) of the stimulus pair on one retina so as to fuse with the single stimulus on the other retina. In both conditions, the separation between the stimulus pair presented to one eye was systematically varied. Experiment 1, with 16 observers, showed that the fused object was seen in front of the nonfused object in the occlusion condition and was seen at the same distance as the nonfused object in the camouflage condition. The perceived depth between the two objects was constant and did not depend on the separation of the stimulus pair presented to one eye. Experiment 2, with 45 observers, showed that the disparity induced by vergence mainly determined the perceived depth, and the depth magnitude increased as the separation of the stimulus pair was made wider. The results suggest that (1) occlusion provides depth-order information but not depth-magnitude information, (2) camouflage provides neither depth-order nor depth-magnitude information, and (3) vergence-induced disparity provides both order and magnitude information.     

The extent of Panum's area and the human cortical magnification factor

The horizontal extent of Panum's fusional area was measured by means of a single-vertical-line stimulus placed at thirty-two locations throughout the peripheral visual field. These results were transformed by using known values of the human cortical magnification factor (CMF), and the hypothesis that variations in the magnitude of Panum's area may be accounted for by variations in the CMF was tested. It was found that the increase in Panum's area with increasing stimulus eccentricity correlates well with the CMF, but that variations in the extent of Panum's area as a function of angular position around the line of sight do not correspond well with the CMF.     

Occlusion as a depth cue in the Wheatstone-Panum limiting case

We examined the hypothesis (Ono & Wade, 1985) that occlusion of far stimuli by a near one on the same visual line can operate as a depth cue in stereograms containing different numbers of targets in the two eyes. By controlling eye positions, we created conditions in which the visual system could interpret the retinal images as originating from stimuli on the visual axis of one eye and also created other conditions in which the origin of the retinal images was ambiguous. In Experiment 1, we presented two lines to one eye and a single line to the other eye. When the image of the line on the temporal side of the line pair on one retina fused with the image of the single line on the other retina, the nonfused line appeared farther away more often than it did when the image on the nasal side fused. In Experiment 2, we used two differently shaped stimuli. In the condition in which the nonfused stimulus represented an object being occluded, it appeared farther away more often than in the four conditions in which it did not. In Experiment 3, we extended the idea to three different objects. When the middle of the three images fused with the single image, the nonfused stimulus appeared farther when it could be interpreted as being occluded than when it could not. In the condition in which the most temporal image fused with the single image, the nonfused stimuli appeared farther than in the condition in which the most nasal one fused. The results supported the hypothesis that occlusion plays a role in depth perception in the Wheatstone-Panum limiting case.     

Children's understanding of their own and others' mental states. Part A. Self‐understanding precedes understanding of others in pretence

We examined 3‐ to 6‐year‐old children's attributions of pretence when their own or another's behaviours were characterized as similar (usually unintentionally) to that of a real or nonexistent animal. In some pretence tasks, we asked children if they were trying to look like or looked like the animal they were characterized as looking like; in others, if and how they could (or why they could not) pretend to be a real or nonexistent animal. Children at 4–6 years of age understood their own pretences better than another's pretences, but even by 6 years of age children continued to fail to understand pretence by another. Across ages children tended to be consistent in their claims about whether or not they looked liked (or were trying to look like) the animal, and whether or not they were pretending to be it. Children appear to take someone's merely looking like an animal as evidence that the person (whether self or other) is pretending to be that animal. Their success on self‐pretence tasks probably results from their unwillingness to believe that their own actions look like those of the animal because they had not intended to look like it.     

Categorization and metaphor understanding.

Glucksberg and Keysar (1990) have proposed a class-inclusion model of metaphor comprehension. This theory suggests that metaphors are not understood as implicit similes but are seen as class-inclusion statements in which the topic of a metaphor is assigned to a diagnostic, ad hoc category, whereas the metaphor's vehicle is a prototypical member of that category. The author claims that verbal metaphors are not simply instantiations of temporary, ad hoc categories but reflect preexisting conceptual mappings in long-term memory that are metaphorically structured. Various evidence from cognitive linguistics, philosophy, and psychology are described in support of this claim. Evidence is also presented that supports, contrary to Glucksberg and Keysar's position, the role of tacit conceptual metaphors in the comprehension of verbal metaphors in discourse.     

Family-centered intensive case management: A step toward understanding individualized care

New York State's initial attempt at individualizing services occurred within the context of an experiment. We randomly assigned children 5–12 years old who were referred for out-of-home placement in treatment foster care to either treatment foster care, Family-Based Treatment (n=15), or to Family-Centered Intensive Case Management (FCICM) (n=27). FCICM used teams of case managers and parent advocates to provide in-home services. Flexible service dollars, respite care, and behavior management skills training were available to assist teams in individualizing care. Preliminary outcomes indicate that children in FCICM are doing as well or better than children assigned to FBT in their functioning and symptom reduction. Parents of children in FCICM have made gains, although not at a statistically significant level, in behavior management skills and family strengths that allow them to provide care for their children at home.     

Toward an understanding of false accusation: The pure case of deviant labeling

The phenomenon of the “falsely accused deviant” was introduced by Becker almost two decades ago (Becker, 1963) and has become a tacit anchor point for subsequent labeling theory. It has, however, received limited systematic analytic explication. This paper first samples a broad range of research findings affirming the breadth and prevalence of false accusation. A classification scheme identifying four fundamental types of false accusations (pure, intentional, legitimatized, and victim based) is then introduced and illustrated. Finally, several propositions pertaining to the societal and organizational preconditions for the occurrence of false accusation are presented and documented. The roles that (1) perceived threat, (2) subcultural heterogeneity, (3) domain protectionism, (4) stereotype adoption, and (5) diagnostic oversimplification play in the emergence of false accusation are highlighted.     

Time Limited Treatment and C. G. Jung's Analytical Psychology

Abstract

The work of C. G. Jung has been largely neglected in recent discussions of time-limited psychotherapy. Notwithstanding this state of affairs, this paper argues that much is to be gained from familiarity with Jung's view on treatment. A brief overview of Jung's general system of psychology is presented, and contrasts are drawn to the work of Freud. Several distinctive characteristics of Jung's view of the clinical process are then identified, and a discussion of the course of treatment is provided with a brief reference to a case of Jung's and to the author's experience working with gay men.     

Learning and understanding in virtual teams.

There are sufficient reasons to conclude that virtual education is not just hype. There are, among others, economic motivations such as bringing one learning module to a larger audience of learners, and pragmatic reasons such as achieving flexibility in time and space for learning, which is especially important for adult learners. However, from a pedagogic point of view there are some doubts. Current technologies meant for learning and working in teams are often designed for functional collaboration (e.g., sharing documents, communicating), but fail to support learning, understanding and team forming (e.g., carrying out pedagogically adequate tasks, understanding each other's work and group dynamic processes) in virtual teams. In order to understand virtual teams, we need to know how we can study learning and understanding in virtual teams. Interesting research questions are: Which concepts are important in understanding virtual teams? How can we measure those concepts, and in what type of setting (e.g., experimental study, case study)? The aim of this special issue is to provide and discuss concepts and pragmatic insights in research on learning and understanding in virtual teams. The aim of this article is to set the stage for those articles.     

Children's fantasy play and emotional understanding.

Examined the relation between affective and cognitive processes in fantasy play and emotional understanding. Sixty-six children in the 1st and 2nd grades played with puppets (Affect in Play Scale; Russ, 1993), answered questions about their understanding of emotions (Kusche Affective Interview-Revised; Kusche, Greenberg, & Beilke, 1988), and completed a measure of verbal intelligence (Wechsler Intelligence Scale for Children-III; Wechsler, 1991). The major finding of this study was that consistent, yet modest, relations were found between dimensions of fantasy play and emotional understanding. Cognitive dimensions of fantasy play, but not affect expression, were related to facets of emotional understanding. These relations were independent of verbal ability. A composite fantasy play score accounted for a significant amount of variance in a composite emotional understanding score when verbal ability was accounted for. Variations in the pattern of correlations for girls and boys suggest sex differences in the relation between fantasy play and emotional understanding. Implications for clinical research and interventions are discussed.     

Symmetric limiting distributions of response probabilities

Necessary and sufficient conditions for the symmetry of the limiting distributions of response probabilities are derived for the Bush and Mosteller two experimenter-controlled events learning model [Bush and Mosteller, 1955].     

The case for coherence in scientific explanations: quantitative details can hurt qualitative understanding

In Experiments 1A and 1B, students read a concise booklet containing 653 words and 6 illustrations describing the formation, propagation, and dispersion of ocean waves (concise group) or an expanded booklet containing 327 additional words and 5 additional illustrations describing relevant mathematical formulas and computations interspersed throughout the lesson (expanded group). In Experiment 2, students viewed a multimedia presentation of narrated animations based on the concise or expanded booklet. In both studies, the expanded group performed more poorly than did the concise group on problem-solving transfer tests. The added quantitative details may have distracted the learner from constructing a qualitative model of the process of ocean waves.