Do recognizable figures enjoy an advantage in binocular rivalry?

Five experiments examined whether recognizable stimuli predominate in binocular rivalry. It was found that a face predominated more than did a pattern equated for spatial frequency, luminance, and contrast; an objective reaction time procedure confirmed predominance of the face. The face was still liable to fragmentation as stimulus size increased. Observers tracked exclusive dominance of a picture of a camouflaged figure (a Dalmatian dog) prior to and then following discovery of the figure's presence; control observers received the same protocol with a scrambled version of the dog stimulus. Compared with control results, predominance of the dog picture was higher even before observers knew of the camouflaged figure. Inversion of the dog figure reduced its predominance. Binocular rivalry is sensitive to object-related, configural properties of a stimulus.     

Spatial range of illusory effects in Müller-Lyer figures

The spatial range of the illusory effects in Müller-Lyer (M-L) figures was examined in three experiments. Experiments 1 and 2 assessed the pattern of bisection errors along the shaft of the standard or double-angle (experiment 1) and the single-angle (experiment 2) M-L figures: Subjects bisected the shaft and the resulting two half-segments of the shaft to produce apparently equal quarters, and then each of the quarters to produce eight equal-appearing segments. The bisection judgments of each segment were referenced to the segment's physical midpoints. The expansion or wings-out and the contraction or wings-in figures yielded similar patterns of bisection errors. For the standard M-L figures, there were significant errors in bisecting each half, and each end-quarter, but not the two central quarters of the shaft. For the single-angle M-L figures, there were significant errors in bisecting the length of the shaft, the half-segment, and the quarter, of the shaft adjacent to the vertex but not the second quarter from the vertex nor in dividing the half of the shaft at the open end of the figure into four equal intervals. Experiment 3 assessed the apparent length of the half-segment of the shaft at the open end of the single-angle figures. Length judgments were unaffected by the vertex at the opposite end of the shaft. Taken together, the results indicate that the length distortions in both the standard and single-angle M-L figures are not uniformly distributed along the shaft but rather are confined mainly to the quarters adjacent to the vertices. The present findings imply that theories of the M-L illusion which assume uniform expansion or contraction of the shafts are incomplete. Received: 15 December 2000 / Accepted: 5 June 2001     

The dissociation of position and extent in Müller-Lyer figures

Three experiments were designed to determine whether Müller-Lyer figures cause a misperception of the positions of their fins and, if they do, whether it is commensurate with the distortion of extent. Observers marked the visible intersection of shaft and fins either with their unseen hands or with their visible hands after the figure had been removed from view. In the former case, no systematic distortions of position were evident. In the latter case, there were small, systematic distortions of position, which were significantly smaller when the observers fixated the target vertex than when they fixated the center of the figure. These differences are discussed in terms of the probable similarities between the control of eye movements and the control of pointing responses. Of particular importance is the finding that even the largest distortions of vertex position were much smaller than the distortions of shaft extent. The results appear to provide evidence of the independence of perceived position from perceived extent in Müller-Lyer figures and to contradict all existing theories of the illusion.     

Duck or rabbit? Reversing ambiguous figures and understanding ambiguous representations

In two studies we investigated 3‐ to 5‐year‐old children’s ability to reverse ambiguous figures and the relation between this ability and the ability to understand multiple representations. Children never reversed before they were informed of the two alternative interpretations of the figures. Even when they were informed of the alternatives and understood that both were possible, 3‐year‐olds and most 4‐year‐olds did not reverse. In contrast, a majority of 5‐year‐olds did reverse. In general, children only reversed if they also passed a standard false belief task. However, there was a closer correlation between reversals and a ‘droodle’ task that involved an understanding of the ambiguity of perceptual representations. These results suggest that the immediate experience of reversal may depend on a more abstract understanding of ambiguous representations.     

Selective adaptation with reversible figures: Don’t change that channel

An adaptation-test paradigm was used in two experiments examining processes underlying the perceived reversals of a rotating Necker cube. Adaptation and test cubes were either the same or different with respect to their visual fields of presentation (Experiment 1) or their sizes (Experiment 2). Results of both experiments indicated that, following subjects’ adaptation to a different cube, reversal rate of the test cube did not differ from that obtained without prior adaptation experience. In contrast, reversal rate of the test cube was elevated following adaptation to the same cube. Additional findings of Experiment 1 were that a test cube presented to the same visual field as the adaptation cube yielded a higher reversal rate than did a simultaneously presented cube in the opposite visual field. Also, the reversal rate of one cube was not influenced by the simultaneous presentation of a second cube. Results of both experiments were interpreted in terms of the fatigue and recovery of multiple, largely independent, localized neural channels. Thus, the results tie reversible-figure illusions to other visual phenomena thought to involve similar fatigue processes within localized visual channels (e.g., tilt, motion, and size aftereffects).     

Do chickens (Gallus gallus f. domestica) decompose visual figures?

To investigate whether learning to discriminate between visual compound stimuli depends on decomposing them into constituting features, hens were first trained to discriminate four features (red, green, horizontal, vertical) from two dimensions (colour, line orientation). After acquisition, hens were trained with compound stimuli made up from these dimensions in two ways: a separable (line on a coloured background) stimulus and an integral one (coloured line). This compound training included a reversal of reinforcement of only one of the two dimensions (half-reversal). After having achieved the compound stimulus discrimination, a second dimensional training identical to the first was performed. Finally, in the second compound training the other dimension was reversed. Two major results were found: (1) an interaction between the dimension reversed and the type of compound stimulus: in compound training with colour reversal, separable compound stimuli were discriminated worse than integral compounds and vice versa in compound training with line orientation reversed. (2) Performance in the second compound training was worse than in the first one. The first result points to a similar mode of processing for separable and integral compounds, whereas the second result shows that the whole stimulus is psychologically superior to its constituting features. Experiment 2 repeated experiment 1 using line orientation stimuli of reversed line and background brightness. Nevertheless, the results were similar to experiment 1. Results are discussed in the framework of a configural exemplar theory of discrimination that assumes the representation of the whole stimulus situation combined with transfer based on a measure of overall similarity.     

Does contour classification precede contour grouping in perception of partially visible figures?

When a figure is only partially visible and its contours represent a small fraction of total image contours (as when there is much background clutter), a fast contour classification mechanism may filter non-figure contours in order to restrict the size of the input to subsequent contour grouping mechanisms. The results of two psychophysical experiments suggest that the human visual system can classify figure from non-figure contours on the basis of a difference in some contour property (e.g. length, orientation, curvature, etc). While certain contour properties (e.g. orientation, curvature) require only local analysis for classification, other contour properties (e.g. length) may require more global analysis of the retinal image. We constructed a pyramid-based computational model based on these observations and performed two simulations of experiment 1: one simulation with classification enabled and the other simulation with classification disabled. The classification-based simulation gave the superior account of human performance in experiment 1. When a figure is partially visible, with few contours relative to the number of non-figure contours, contour classification followed by contour grouping can be more efficient than contour grouping alone, owing to smaller input to grouping mechanisms.     

Who is crossing where? Infants' discrimination of figures and grounds in events

To learn relational terms such as verbs and prepositions, children must first dissect and process dynamic event components. This paper investigates the way in which 8- to 14-month-old English-reared infants notice the event components, figure (i.e., the moving entity) and ground (i.e., stationary setting), in both dynamic (Experiment 1) and static representations of events (Experiment 2) for categorical ground distinctions expressed in Japanese, but not in English. We then compare both 14- and 19-month-old English- and Japanese-reared infants’ processing of grounds to understand how language learning interacts with the conceptualization of these constructs (Experiment 3). Results suggest that (1) infants distinguish between figures and grounds in events; (2) they do so differently for static vs. dynamic displays; (3) early in the second year, children from diverse language environments form nonnative – perhaps universal – event categories; and (4) these event categories shift over time as children have more exposure to their native tongue.     

Screen Christologies: An evaluation of the role of Christ‐figures in film

Throughout the course of Christian history, the nature and identity of Jesus Christ has been interpreted in a wide variety of ways. In this article, I will suggest that the root tensions between the divine and human natures of Christ, as epitomized in the Alexandrian and Antiochene controversies of the Patristic Church, find a contemporary expression in the abundance of Christ‐figures that have emerged in contemporary film. Attention will be given to the functions that such figures perform, and their relationship to the Person of Christ as understood by the respective ‘high’ (Alexandrian) and ‘low’ (Antiochene) schools of Christology. I will conclude that, provided sufficient emphasis is placed on the humanity of the Christ‐figure, a process of redemption analogous to that found in traditional Christian accounts of the Person of Christ is operative through such films.     

Adaptation effects and reversible figures: A comment on Horlitz and O’Leary

In a recent article, Horlitz and O’Leary (1993) offer a reinterpretation of the results of several studies over the past 40 years that have employed the prolonged-inspection technique in the investigation of reversible figures. Specifically, they contend that, contrary to the favored interpretation of neural adaptation effects, the results of these studies reveal the combined influence of such topdown processes as attention and perceptual learning as well as such methodological difficulties as unwanted demand characteristics. In this note, we examine their analysis of the literature, their alternative theoretical model, and the supporting conclusions they draw from their two experiments. We argue that there is considerable evidence from a variety of studies for the joint role of bottom-up and top-down processes in reversible figures. Moreover, we propose that Horlitz and O’Leary’s own research, rather than eliminating the possibility of neural-adaptation effects, is best conceptualized as providing additional evidence for the role of higher-order processes in these phenomena.     

Children's understanding of ambiguous figures: Which cognitive developments are necessary to experience reversal?

In two experiments involving one hundred and thirty-eight 3- to 5-year-olds we examined the claim that a complex understanding of ambiguity is required to experience reversal of ambiguous stimuli [Gopnik, A., & Rosati, A. (2001). Duck or rabbit? Reversing ambiguous figures and understanding ambiguous representations. Developmental Science, 4, 175–183]. In Experiment 1 a novel Production task measured the ability to acknowledge both interpretations of ambiguous figures. This was as easy as and significantly correlated with a False Belief task, and easier than a Droodle task. We replicated this finding in Experiment 2, and also found that perceiving reversal of ambiguous figures was harder than either the False Belief or Production tasks. In contrast to previous findings, the Reversal and Droodle tasks were not specifically related. We conclude that children only attempt reversal once they can understand the representational relationship between the figure and its two interpretations. The process resulting in reversal however is hard, probably requiring additional developments in executive functioning and imagery abilities.     

Which is more critical in identification of random figures,endpoints or closures?1

The present study intended to examine the criticality of the presence of endpoints and its complementary state, the presence of closures, in early figural identification. Three experiments used a same/different judgment task for simultaneously presented pairs of random figures. Rigorous control over the selections of stimulus figures containing closures and endpoints was ensured. Latencies predicted by six explanations of figural identification (i.e. parallel and the presence of endpoint detection; parallel and closure detection; serial, exhaustive and endpoint detection; serial, exhaustive and closure detection; serial, self‐terminating and endpoint detection; and serial, self‐terminating and closure detection) were evaluated by the obtained patterns of latencies. The experiments persistently indicated that serial, self‐terminating feature detections were executed as the means of the identification. Experiments 1 and 2 showed that closures were detected faster than endpoints. Experiment 3 further suggested that multiple closures were detected faster than a single closure.     

The reversed Müller-Lyer illusion in conventional and in wing-amputated Müller-Lyer figures

Summary When the wings of the conventional or four-wing Müller-Lyer figures are displaced away from the shaft, the apparent elongation of the wings-out figure decreases and the apparent contraction of the wings-in figure changes to apparent elongation. Worrall and Firth (1974) reported a different pattern of illusion change for two-wing Müller-Lyer figures containing wings at only one end of the shaft. Whereas moving the wings away from the shaft decreased the magnitude of the wings-in illusion, it changed the wings-out illusion from apparent elongation to apparent contraction. The effect of wing displacement upon the Müller-Lyer illusion was measured in three experiments. Illusion magnitude was assessed by obtaining judgments of either the length (Experiment 1) or the apparent midpoint (Experiments 2 and 3) of the shaft of four-wing (Experiment 1), two-wing (Experiments 1–3), and one-wing (Experiments 1 and 2) Müller-Lyer figures. Both measures of the illusion showed that displacement of the wings away from the shaft had similar effects on the four and two-wing Müller-Lyer figures. The results are discussed in the context of assimilation theories of the Müller-Lyer illusion, and a possible reason for the apparent inconsistency between Worrall and Firth's conclusions and the present findings is outlined.     

Is the matching familiar figures test a measure of cognitive style? A warning for users

A probabilistic model of reflection-impulsivity as measured by the Matching Familiar Figures Test (MFFT) is presented and tested on 77 fourth graders. In testing the model two groups emerged, a random response group (n = 22) and a cognitive response group (n = 55), who use the evaluation process. Correlations among latencies, total errors, initial errors, school-scores, and IQs were compared for our total sample and the two groups. The correlation of MFFT latencies and errors disappeared for the random-response group and new correlations with errors appeared while the cognitive response group kept a statistically significant correlation of latencies with errors and no other error correlation was shown. This last group was classified by Kagan's median-split procedure showing that most reflective subjects kept their classification. Preliminary results suggest a reinterpretation of reflection-impulsivity literature, especially as related to the impulsive style.     

On a class of “impossible” figures: A new language for a new analysis

Multibar figures provide a class of illusions that have been used by psychologists as well as by artists like Escher. For scientific purposes one needs as precise a definition and analysis as possible for these figures. A first attempt at this has been made by Cowan (1974) with the theory of braids. The present work points out some semantic and technical problems not dealt with by Cowan, and proposes a new language for the study of multibar figures. This language is shown to be incomplete, and some further problems are reviewed.     

A test of Vitz and Todd’s model of the judged complexity of straight-line figures

Two sets of stimuli, each consisting of nine geometric patterns, were computer-generated: in one set, the patterns were squares which were partitioned randomly into rectangles; in the other, the patterns were squares which were partitioned randomly into polygons. Ten subjects gave magnitude estimates of the complexity of the stimuli. The Vitz and Todd (1971) index of complexity was not a consistently better predictor of estimated complexity than the ratio of the number of lines in each pattern to an index of symmetry. Moreover, the power function relating the complexity estimates of the rectangular partitions to the Vitz and Todd index was significantly different from the power function relating the complexity of the polygonal partitions to the Vitz and Todd index. It is concluded that the Vitz and Todd model requires major additional assumptions in order to be a candidate for a process model of pattern perception.     

Les figures temporelles de l’adulte en reconversion vers la création d’entreprise

IntroductionMore and more vocational retraining in France lead the adults to break with his former career for engaging in a new occupation. This entrepreneurial project is at the crossroads of several temporalities, which this paper has investigated.ObjectiveWe study mainly the processes of retraining to start up a company. The goal is to know if the devices of accompaniment to the construction of the entrepreneurial project come to support or interfere the temporalities of the adult in retraining to creation of company. We want to know how these adults in retraining seize these temporalities of the entrepreneurial process (beliefs, feelings, representations) and these temporalities of the assistance and counseling devices (in a structuring way, to gradually build this new professional identity of entrepreneur, or limiting way, like a form of subjugation).MethodNine adults were interviewed in semi-structured interviews about their experience of retraining to start a new business. This research provides a key to seeing the plural temporalities arising from the relationship between the desire for autonomy and the normative framework of the devices.ResultsA thematic content analysis was carried out, to identify the phases of the transition, the temporalities of the processes of retraining and creation, the logics of actions and the forms of relationships.ConclusionThe actor strives to make the limiting and emancipatory temporalities coexist through a personal work of appropriation. This allowed to construct four figures of adulthood in retraining towards entrepreneurship: the author of his artwork, the decision maker of his future, the coin adult of his actions and his time, and the runner.     

What perceptual rules do capuchin monkeys (Cebus apella) follow in completing partly occluded figures?

Capuchin monkeys (Cebus apella) matched a variety of rodlike figures, distinguishable only by their central portions. The monkeys were then tested for perceptual completion rules by examining which comparison figures they would choose as matching the sample with the critical central portion occluded by a horizontal belt. In Experiment 1, the monkeys overwhelmingly chose a straight rod over disconnected rods and rods having irregular shapes at their center, irrespective of the presence-absence of common motion of visible parts of the samples. The monkeys chose a connected rod for relatable rods and disconnected rods for non-relatable ones in Experiment 2. In Experiments 3 and 4, some of the monkeys chose rods specified by the global regularity of the contour, whereas others did not. Experiment 5 showed that humans and capuchin monkeys basically follow similar perceptual rules in completing occluded contours, but the global regularity rule may be stronger in humans.     

Satiation or availability? Effects of attention,memory, and imagery on the perception of ambiguous figures

The prolonged-inspection technique has been used to demonstrate effects of satiation on the perception of ambiguous figures. We propose that the inspection phase, in which subjects view an unambiguous version of the stimulus prior to observing the ambiguous figure, does not create neural fatigue but rather provides a context in which the alternative percept is apprehended and gains perceptual strength through processes such as imagination or memory. The consequent availability of the alternative organization drives the perceptual phenomena that have been thought to reflect satiation. In Experiment 1, we demonstrated that (1) preexperimental exposure to the target figures and (2) allocation of attention to the-inspection figures-were both necessary in order to obtain results similar to those predicted by the satiation model. In Experiment 2, we obtained similar results, finding that effects of prior inspection were greater the greater the amount and availability of information regarding the alternative percept during the inspection phase. Subjects who generated visual images of the noninspected alternative during inspection yielded results comparable to those from subjects to whom both versions were presented isuaily.