Perception of simple figures: implicit-shape constancy and mental rotation.

Adults were shown simple figures either drawn on their own or on a face of a depicted cube. Under each of these conditions they were required to find identical figures in an array of stimuli of either the first or the second type. The response chosen determined the next stimulus used, the figures in both being identical. Four chains of 10 responses were thus obtained. Comparison of the choices reveals that the set consisting of 'plain' responses to 'cube' stimuli diverges significantly from the other three sets. This result is discussed in the context of other studies of implicit-shape constancy.     

Cues to viewing distance for stereoscopic depth constancy.

A veridical estimate of viewing distance is required in order to determine the metric structure of objects from binocular stereopsis. One example of a judgment of metric structure, which we used in our experiment, is the apparently circular cylinder task (E B Johnston, 1991 Vision Research 31 1351-1360). Most studies report underconstancy in this task when the stimulus is defined purely by binocular disparities. We examined the effect of two factors on performance: (i) the richness of the cues to viewing distance (using either a naturalistic setting with many cues to viewing distance or a condition in which the room and the monitors were obscured from view), and (ii) the range of stimulus disparities (cylinder depths) presented during an experimental run. We tested both experienced subjects (who had performed the task many times before under full-cue conditions) and na?ve subjects. Depth constancy was reduced for the na?ve subjects (from 62% to 46%) when the position of the monitors was obscured. Under similar conditions, the experienced subjects showed no reduction in constancy. In a second experiment, using a forced-choice method of constant stimuli, we found that depth constancy was reduced from 64% to 23% in na?ve subjects and from 77% to 55% in experienced subjects when the same set of images was presented at all viewing distances rather than using a set of stimulus disparities proportional to the correct setting. One possible explanation of these results is that, under reduced-cue conditions, the range of disparities presented is used by the visual system as a cue to viewing distance.     

Intelligence level as a variable in the perception of shape

The relation between shape constancy and intelligence was investigated by determining the functions relating matched shape to the angle of inclination of a circular test-object for groups at four levels of intelligence. Subjects were obtained from groups of institutionalized mental defectives, slow learners from the public schools, unselected undergraduates, and undergraduates who had been awarded scholarships. With increasing intelligence level the matches tend to approach the prediction based on the law of the retinal image thus demonstrating an inverse correlation between intelligence and the extent to which constancy is demonstrated. Since it is known the instructions given to the subject are a variable in shape constancy, it is suggested that the present data are the result of different attitudes adopted by the subjects at the various intelligence levels. The more intelligent subjects are assumed to adopt an analytic attitude in the experimental situation, while the less intelligent tend to maintain their everyday, non-analytic modes of perceiving.     

Influence of flicker on perceived size and depth

Previous research (e.g., Wong & Weisstein, 1984a, 1985) has shown that flickering stimuli appear to be more distant than nonflickering stimuli at the same physical distance. Given this relation between flicker and perceived depth, inappropriate constancy scaling theories predict that flickering stimuli should be perceived as larger than nonflickering ones. In contrast, links between flicker and motion perception suggest that flickering stimuli should be perceived as smaller than nonflickering ones. Two experiments tested these contrasting predictions. In Experiment 1, 22 subjects compared flickering and nonflickering vertical lines and reported that the flickering stimulus appeared significantly smaller than the nonflickering one. In Experiment 2, 21 subjects reported that the stimuli used in Experiment 1 produced depth effects similar to those reported in previous experiments: flickering stimuli were perceived as more distant than nonflickering ones. The observed effect of flicker on perceived size was contrary to predictions from inappropriate constancy scaling theory, but consistent with views that motion and flicker are processed by the same pathway.     

The effects of books and gender constancy development on kindergarten children's sex-role attitudes

The effects of symbolic models and level of gender understanding on children's sex-role attitudes was investigated. Kindergarten boys and girls heard and discussed books whose characters depicted either traditional or nontraditional sex-role behaviors. Attitudes toward males and females were measured before and after the picture book treatment. When the study began, children were screened for gender understanding so that half were able to make other-gender constancy judgments, and half were not able to make other-gender constancy judgments. Prior to the treatment, boys and children who had attained gender constancy were slightly negative toward males and neutral toward females, whereas girls and children who had not attained gender constancy were very negative toward males and very positive toward females. Exposure to traditional books had the effect of enhancing attitudes toward males and decreasing attitudes toward females. Exposure to nontraditional books had the opposite effect of decreasing attitudes toward males and enhancing attitudes toward females. The effects of the picture book treatment on attitudes toward females were more pronounced for children who had attained other-gender constancy. Implications for social learning and cognitive-developmental theories of sex-role development are discussed.     

Colour constancy in goldfish and man: influence of surround size and lightness

Colour constancy was investigated by using a series of 10 simultaneously presented surface colours ranging in small steps from green through gray to red-purple. Goldfish were trained to select one medium test field when the entire setup was illuminated with white light. In the tests, either red or green illumination was used. Colour constancy, as inferred from the choice behaviour, was perfect under green illumination when the test fields were presented on a gray or a white background, but imperfect on a black background. Under red illumination and a white background, however, colour constancy was overcompensated. Here, a colour contrast effect was observed. The influence of background lightness was also found when the surround was restricted to a narrow annulus of 4-11 mm width (test field diameter: 14 mm). By applying colour metrics it could be shown that the von Kries coefficient law can describe the overall effect of colour constancy. For an explanation of the effect of surround size and lightness, lateral inhibitory interactions have to be assumed in addition, which are also responsible for simultaneous colour contrast. Very similar results were obtained in experiments with the same colours in human subjects. They had to name the test field appearing 'neutral' under the different illumination and surround conditions, as tested in the goldfish experiment.     

Age and prospective memory

This paper reports an investigation into the effects of age, intelligence, and retrospective memory on performance in a prospective memory task in which subjects aged between 52 and 95 were required to telephone once a day either between two times or at an exact time. The most important influence on performance was how subjects chose to remember to make the telephone calls. The best performance was from subjects who telephoned either in conjunction with another routine event or engaged in some form of advanced planning of the daily schedule. The worst performance was from those who relied on internal cues from their own memory. Performance was intermediate from those who used external cues such as notes or diary entries. Subjects in the between condition were less likely to choose internal cues than those in the exact condition, possibly because the task appeared more difficult, and this resulted in their showing superior performance. The effect of age was influenced by the cue used. For subjects using internal cues, those who forgot were older than those who remembered, whereas for subjects using the other cues, those who forgot were younger than those who remembered. Regardless of cue, self-ratings of cognitive failures were related to performance such that those who reported more minor everyday mistakes were indeed more likely to forget to telephone. While there was some indirect effect of general intelligence on performance in the task, there was no relationship between retrospective memory scores and whether or not subjects remembered to telephone.     

The effect of instructions on the judgement of brightness

A brightness constancy experiment using ten subjects showed that different instructions significantly affect the subject's PSE judgement. Variations in the reflectance of the standard target and in the background and illumination of the variable target did not influence the effect of different instructions. The use of the D-ratio as constancy index in this study confirms an earlier theoretical finding that other brightness constancy ratios introduce an artefact into experimental results.     

嗓音源判断过程中的范畴效应和通道效应

该项研究通过设计4种实验条件,旨在探讨不同嗓音词的再认和嗓音判断过程各自的特点及其相互联系。4种实验条件是由2种诵读方式和2种测试方式组合而成,2种诵读方式为同范畴同嗓音和同范畴异嗓音,2种测试方式为视觉呈现和听觉呈现。52名大学生被试随机分成4个独立的组,分别接受一种实验处理。实验结果显示：(1)同范畴同嗓音条件与同范畴异嗓音条件相比,前者项目词的嗓音源判断效果好。提示增加相同记忆源项目间语义联系将有利于记忆源的检测判断。(2)项目再认与项目嗓音判断结果不完全一致,只有在诵读方式为同范畴同嗓音测试方式为听觉呈现情境下,两者有较高的正相关。(3)在同范畴同嗓音诵读条件下,再认反映出学习和测试通道源一致性优势效应,嗓音判断没有反映出通道源一致性优势效应。     

Binocular shape constancy from novel views: the role of a priori constraints

We tested shape constancy from novel views in the case of binocular viewing, using a variety of stimuli, including polyhedra, polygonal lines, and points in 3-D. The results of the psychophysical experiments show that constraints such as planarity of surface contours and symmetry are critical for reliable shape constancy. These results are consistent with the results obtained in our previous psychophysical experiments on shape constancy from novel views in the presence of a kinetic depth effect (Pizlo & Stevenson, 1999). On the basis of these results, we developed a new model of binocular shape reconstruction. The model is based on the assumption that binocular reconstruction is a difficult inverse problem, whose solution requires imposing a priori constraints on the family of possible interpretations. In the model, binocular disparity is used to correct monocularly reconstructed shape. The new model was tested on the same shapes as those used in the psychophysical experiments. The reconstructions produced by this model are substantially more reliable than the reconstructions produced by models that do not use constraints. Interestingly, monocular (but not binocular) reconstructions produced by this model correlate well with both monocular and binocular performance of human subjects. This fact suggests that binocular and monocular reconstructions of shapes in the human visual system involve similar mechanisms based on monocular shape constraints.     

The effect of tempo and tone duration on rhythm discrimination

Rhythm constancy was investigated in two experiments. In Experiment 1, the first rhythm was presented at one tempo, the second rhythm was presented at a different tempo, and subjects judged whether the relative timing structures were identical (i.e., was the first rhythm merely sped up or slowed down to generate the second rhythm?). For the nonmetric rhythms used here, subjects perceived the rhythm in terms of the figural grouping of the tones, and rhythm constancy broke down between slower and faster tempos. In Experiment 2, the first rhythm was presented in tones of one duration; the second rhythm was presented in tones of a different duration; and subjects judged whether the timing structures of the tone onsets were identical (the two rhythms were presented at the same tempo). These results indicated a high degree of constancy; subjects found it easy to discriminate the timing structures. These results confirm that the onset timing is critical to rhythm perception and suggest that rhythm perception at slower rates (2 elements/sec) differs from rhythm perception at faster rates (3–4 elements/sec).     

The response criterion,the stimulus configuration,and the relationship between brightness contrast and brightness constancy

Four experiments were designed to investigate the nature of the relationship between brightness contrast and brightness constancy while controlling the response criterion, the area of the surround, the stimulus configuration, and the mode of appearance of the modulus target. Ten Os in each of the four experiments estimated the apparent whiteness or brightness of targets with different contrast ratios. All targets were viewed at several illumination levels. Most constancy (whiteness and brightness) functions displayed shallow slopes that reflected a good approximation to constancy. The functions within Experiments I, III, and IV were vertically displaced and parallel; those in Experiment II were vertically displaced and increased in slope. This suggests that decreasing the contrast ratio had no effect on the tendency towards constancy when the area of the surround was greater than that of the target but resulted in a decrease in constancy when the area of the surround was equal to that of the target.     

Cerebral achromatopsia: colour blindness despite wavelength processing

Cortical colour blindness is caused by brain damage to the ventro-medial occipital and temporal lobes. A possible explanation is that the pathway responsible for transmitting information about wavelength and its subsequent elaboration as colour has been destroyed at the cortical level. However, several signs of chromatic processing persist in an achromatopsic subject who, despite his inability to tell colours apart, can still detect chromatic borders, perceive shape from colour, and discriminate the direction in which a striped pattern moves when the determination of direction requires the viewer to 'know' which stripes have a particular colour. Perhaps only the information about wavelength that leads to conscious awareness of colour has been destroyed. It is unclear whether incomplete achromatopsia is merely a less severe form of the disorder or whether it is qualitatively different, perhaps reflecting impaired colour constancy. In monkeys, removing cortical area V4 impairs performance on colour constancy tasks but, invariably, impairs several other aspects of visual perception. If the lesion that causes total achromatopsia in human subjects corresponds to area V4 in monkeys, it is an unsolved puzzle that a totally achromatopsic subject paradoxically demonstrates certain characteristics of colour constancy, unless his residual performance reflects the much underrated retinal contribution to colour constancy.     

Effects of attack and uncontrollable noise on aggression

After being either attacked or treated in a more neutral manner by an experimental confederate, male subjects shocked the confederate while being stimulated by loud noise. Among previously attacked subjects, possession of control over offset of the noise led to the delivery of shocks significantly shorter in duration than those given by subjects who did not have control. Mere predictability of noise offset did not have the same effect. Subjects who could control the noise did not differ from those who heard no noise with respect to the duration of shocks given. Noise had no effect on shock duration among nonattacked subjects. In a follow-up study subjects who were given bogus information that they were aroused by noise were less punitive toward an attacking confederate than subjects given no such information. The overall conclusion is that noise facilitates aggression in subjects who have been instigated to aggress to the degree that noise-produced arousal is misattributed to the instigating stimulus.     

Size-distance perception in preschool children.

Children between three and six years of age matched the “apparent” and “real” size of familiar and unfamiliar objects 3, 6, or 9 feet away. Prior to the experimental sessions, the children were divided into two groups: (a) those who could distinguish the phenomenal from the real sizes of the arcs in the Jastrow illusion (the “Realists”) and (b) those who could not (the “Phenomenalists”). The results suggest that all children perceived size constancy up to distances of 9 feet solely on the basis of visual information.     

Characters and their perspectives in narratives describing spatial environments

Summary This paper explores how people represent spatial information involving two perspectives associated with characters who share the same environment. Subjects first learned a narrative that described a scene with eight landmarks surrounding two characters who had the same or different perspective. Afterwards, subjects were given blocks of three-sentence items to be read at their own pace. The first two sentences guided the reader's attention to one character, while the third sentence described a spatial relation between a character and a landmark; subjects had to verify whether the relation was true or false. The results showed that it took longer to verify sentences after learning two-perspective narratives than it did with those of one perspective, and after reading items involving two characters rather than one. Both effects were significant and independent. To explain the perspective effect, it is proposed that subjects build a single perspective-free mental model that is instantiated as a particular perspective when necessary. The character effect has to do with modeling the characters' nonspatial traits. Finally, spatial skills were a predictor of subjects' performance, indicating individual differences in modeling efficiency.     

Finite-state recall revealed by backward learning curves constructed from confidence ratings

Two experiments were carried out to show that the constancy of Type II d’ in recall is not an artifact, but is due to finite-state processes as suggested by Bernbach (1967). The following conclusions were reached: (1) The constancy of Type II d’ is not an artifact due to the inclusion of intralist intrusions in the class of incorrect responses; (2) backward learning curves constructed from confidence ratings gave clear evidence of all-or-none recall; (3) recall appeared to be all or none whether the subjects learned by rote or with a mnemonic; (4) the discriminability index derived from Luce’s (1959) choice theory did not exhibit constancy over trials, unlike Type II d’ and despite the fact that backward rating curves indicated all-or-none processes.     

Children's size judgments when size and distance vary: Is there a developmental trend to overconstancy?

A review of the experimental literature on size constancy in children shows that studies permitting unrestricted viewing in natural settings provide only limited support for the hypothesis, proposed by Wohlwill, of a developmental trend from under- to overconstancy. A study is reported in which subjects aged 8 to 18 years made magnitude estimations of height for targets whose height and distance from them varied. For distances up to 15 m, and heights from 5 to 50 cm, size constancy prevailed at all ages: The same number was assigned to a given height at every distance. If a developmental trend exists, it requires either younger subjects or greater distances to be revealed.     

Magnitude scales,category scales,and the general psychophysical differential equation

The general psychophysical differential equation (GPDE) which relates scale values and Weber functions for two subjective variables was tested statistically with data from a number of category rating and magnitude estimation experiments. In all tests. it was investigated whether the GPDE is compatible with the assumption that the Weber function of the category scale is constant. This assumption implies that the category scale may be regarded as a discrimination scale. The tests were carried out by estimating the Weber function of the category scale by means of the GPDE and testing these estimates for constancy, For group data, there were fairly small systematic deviations from constancy across different experiments in the Weber functions that were estimated by the GPDE, and the hypothesis of a constant estimated Weber function could not be rejected statistically (p>.05) in most experiments. For individual data the estimated Weber functions deviated from constancy in idiosyncratic ways, and these deviations were statistically significant (p<.05)for most subjects.     

Some principles governing changes in the apparent lightness of test surfaces isolated from their normal backgrounds

When smooth matt test surfaces are suspended by fine threads in a strong illumination gradient and in isolation from any ordinary background, lightness constancy fails. It may be restored by introducing other objects into the field in the same plane as the test surfaces. Using a large number of subjects making independent judgements by a comparison scale method, the present investigation attempts to discover the principles underlying the restoration of lightness constancy by the introduction of inducing surfaces of varied size and reflectance at varied distances from the test surface.