Pseudocontingencies in a simulated classroom

The pseudocontingency (PC) illusion is investigated in a simulated classroom setting. Related to the notion of ecological correlations, PCs arise when the assessment of contingencies at the individual level is affected by the base-rate relations at the group level. Positive PCs arise when base rates of 2 variables are skewed in the same direction (e.g., high ability and high motivation), whereas negative PCs arise when base rates are skewed in opposite directions. Experiment 1 demonstrates that PCs between student ability and motivation are contingent on effective base-rate assessment at the group level, with a bias toward positive PCs reflecting prior expectancies. Ruling out prior expectancies, Experiment 2 yields symmetric positive and negative PCs. Experiment 3 provides evidence for PC effects on gender stereotypes. Finally, Experiment 4 extends PCs from group base rates to individual student base rates, ruling out an explanation in terms of capacity deficits or inability to assess individuating information.     

Pseudocontingencies derived from categorically organized memory representations

Pseudocontingencies (PCs) allow for inferences about the contingency between two variables X and Y when the conditions for genuine contingency assessment are not met. Even when joint observations X _i and Y _i about the same reference objects i are not available or are detached in time or space, the correlation r(X _i ,Y _i ) is readily inferred from base rates. Inferred correlations are positive (negative) if X and Y base rates are skewed in the same (different) directions. Such PC inferences afford useful proxies for actually existing contingencies. While previous studies have focused on PCs due to environmental base rates, the present research highlights memory organization as a natural source of PC effects. When information about two attributes X and Y is represented in a hierarchically organized categorical memory code, as category-wise base rates p(X) and p(Y), the reconstruction of item-level information from category base rates will naturally produce PC effects. Three experiments support this contention. When the yes base rates of two respondents in four questionnaire subscales (categories) were correlated, recalled and predicted item-level responses were correlated in the same direction, even when the original responses to specific items within categories were correlated in the opposite direction.     

Differential use of distance and location information for spatial localization

Five experiments are reported in which subjects judged the movement or spatial location of a visible object that underwent a combination of real and induced (illusory) motion. When subjects attempted to reproduce the distance that the object moved by moving their unseen hands, they were more affected by the illusion than when they pointed to the object's perceived final location. Furthermore, pointing to the final location was more affected by the illusion when the hand movement began from the same position as that at which the object initially appeared, as compared with responses that began from other positions. The results suggest that people may separately encode two distinct types of spatial information: (1) information about the distance moved by an object and (2) information about the absolute spatial location of the object. Information about distance is more susceptible to the influence of an induced motion illusion, and people appear to rely differentially on the different types of spatial information, depending on features of the pointing response. The results have important implications for the mechanisms that underlie spatially oriented behavior in general.     

Reading is believing: the truth effect and source credibility

Five experiments explored how source reliability influences people’s tendency to rate statements as more credible when they were encountered earlier (the truth effect). Undergraduates read statements from one reliable source and one unreliable source. Statements read multiple times were perceived as more valid and were more often correctly identified on a general knowledge test than statements read once or not at all. This occurred at varying retention intervals whether the statements originated from a reliable or unreliable source, when people had little memory for the statements themselves or their source, and when the discrediting information about the sources came either before or after reading the facts. While repetition aided recognition and source accuracy, both were unaffected by the reliability of the source. Consistent with the source monitoring framework, familiarity may create an illusion of truth for statements when people lack source-specifying cues, especially cues regarding the reliability of the source.     

Positive illusion in close relationships

The literature regarding self-other comparisons suggests that self-enhancing perceptions are prevalent, including forms of “illusion” such as excessively positive self-evaluation, unrealistic optimism, and exaggerated perceptions of control. Concepts from optimal distinctiveness theory served as the basis for two experiments examining whether illusion functions similarly when the context of evaluation involves a relationship. In both experiments participants rated themselves, the best friend, and the average other—or their own romantic relationships, the best friend's relationship, and the relationship of the average other–using scales measuring positivity of evaluation, optimism regarding the future, and perceptions of control. In both experiments, participants exhibited centrality-based differentiation, rating targets more favorably to the degree that the target was more central to their social identity. Patterns of differentiation differed for the two contexts: In the individual context, participants differentiated themselves and their friends from the average other. In the relationship context, participants differentiated their own relationships from the relationships of friends and average others. Also, participants rated individuals as more controllable than relationships. Participants in Experiment 2 provided information regarding potential predictors of illusion. Analyses of these data suggest that favorable centrality-based differentiation may be partially accounted for by impression management, global self-esteem (particularly in the individual context), and commitment level (particularly in the relationship context).     

Attentional control settings modulate susceptibility to the induced Roelofs effect

When a visible frame is offset laterally from an observer's objective midline, the subjective midline is pulled toward the frame's center, causing the frame and any enclosed targets to be misperceived as being shifted somewhat in the opposite direction. This illusion, the Roelofs effect, is driven by environmental (bottom-up) visual cues, but whether it can be modulated by top-down (e.g., task-relevant) information is unknown. Here, we used an attentional manipulation (i.e., the color-contingency effect) to test whether attentional filtering can modulate the magnitude of the illusion. When observers were required to report the location of a colored target, presented within an array of differently colored distractors, there was a greater effect of the illusion when the Roelofs-inducing frame was the same color as the target. These results indicate that feature-based attentional processes can modulate the impact of contextual information on an observer's perception of space.     

Motivational influences on impression formation: outcome dependency, accuracy-driven attention, and individuating processes

How might being outcome dependent on another person influence the processes that one uses to form impressions of that person? We designed three experiments to investigate this question with respect to short-term, task-oriented outcome dependency. In all three experiments, subjects expected to interact with a young man formerly hospitalized as a schizophrenic, and they received information about the person's attributes in either written profiles or videotapes. In Experiment 1, short-term, task-oriented outcome dependency led subjects to use relatively individuating processes (i.e., to base their impressions of the patient on his particular attributes), even under conditions that typically lead subjects to use relatively category-based processes (i.e., to base their impressions on the patient's schizophrenic label). Moreover, in the conditions that elicited individuating processes, subjects spent more time attending to the patient's particular attribute information. Experiment 2 demonstrated that the attention effects in Experiment 1 were not merely a function of impression positivity and that outcome dependency did not influence the impression formation process when attribute information in addition to category-level information was unavailable. Finally, Experiment 3 manipulated not outcome dependency but the attentional goal of forming an accurate impression. We found that accuracy-driven attention to attribute information also led to individuating processes. The results of the three experiments indicate that there are important influences of outcome dependency on impression formation. These results are consistent with a model in which the tendency for short-term, task-oriented outcome dependency to facilitate individuating impression formation processes is mediated by an increase in accuracy-driven attention to attribute information.     

日常环境中的暴力暴露对攻击行为的长期影响:一个有调节的中介模型

以850名大学生为被试,探讨日常环境中的暴力暴露与攻击行为的关系,并在此基础上提出一个有调节的中介模型,考察攻击性信念的中介作用和人际信任的调节作用。结果发现:(1)日常环境中的暴力暴露对攻击行为有显著的正向预测作用;(2)攻击性信念在日常环境中的暴力暴露与攻击行为的关系中起部分中介作用;(3)攻击性信念的中介作用会受到人际信任的调节。对于低人际信任个体,攻击性信念起部分中介作用;对于高人际信任个体,攻击性信念的中介效应不显著,日常环境中的暴力暴露对攻击行为只有直接作用。     

Temporal processing characteristics of the Ponzo illusion

Many visual illusions result from assumptions of our visual system that are based on its long-term adaptation to our visual environment. Thus, visual illusions provide the opportunity to identify and learn about these fundamental assumptions. In this paper, we investigate the Ponzo illusion. Although many previous studies researched visual processing of the Ponzo illusion, only very few considered temporal processing aspects. However, it is well known that our visual percept is modulated by temporal factors. First, we used the Ponzo illusion as prime in a response priming task to test whether it modulates subsequent responses to the longer (or shorter) of two target bars. Second, we used the same stimuli in a perceptual task to test whether the Ponzo illusion is effective for very short presentation times (12 ms). We observed considerable priming effects that were of similar magnitude as those of a control condition. Moreover, the variations in the priming effects as a function of prime-target stimulus-onset asynchrony were very similar to that of the control condition. However, when analyzing priming effects as a function of participants’ response speed, effects for the Ponzo illusion increased in slower responses. We conclude that although the illusion is established rapidly within the visual system, the full integration of context information is based on more time-consuming and later visual processing.     

The illusion of clarity: Image segmentation and edge attribution without filling-in

It comes as no surprise that viewing a high-resolution photograph through a screen reduces its clarity. Yet when a coarsely quantized (i.e., pixelated) version of the same photo is seen through a screen its clarity is increased. Six experiments investigated this illusion of clarity. First, the illusion was quantified by having participants rate the clarity of quantized images with and without a screen (Experiment 1). Interestingly, the illusion occurs both when the wires of the screen are aligned with the blocks of the quantized image and when they are shifted horizontally and vertically (Experiments 2 and 3), casting doubt on the hypothesis that a local filling-in process is involved. The finding that no illusion occurs when the photo is blurred rather than quantized (Experiment 4) and that the illusion is sharply reduced when visual attention is divided (Experiment 5) argue for an image segmentation process that falsely attributes the edges of the quantized blocks to the screen. Finally, the illusion is larger when participants adopt an active rather than a passive cognitive strategy (Experiment 6), pointing to the importance of cognitive control in the illusion.     

A Comparison of Different Methods for the Elicitation of Attribute Weights: Structural Modeling,Process Tracing,and Self-Reports

This study investigates whether structural modeling, process tracing, and self-reports are able to provide similar information about attribute weights in multiattribute evaluation processes. In three experiments subjects had to evaluate a large number of profiles of fictitious persons described on a number of attributes. The experiments differed in type of judgment task, type of subjects, and number of attributes. Subject attribute weights were derived in all cases by fitting a statistical model (statistical weights), by analyzing verbal protocols (verbal protocol weights), and by directly asking the subject how important the attributes are for the judgments (subjective weights). Correspondence between the three sets of weights is examined in two ways: by computing the correlation between three sets of weights and by calculating how adequately the different sets of weights, applied in a linear model, can predict the subject′s judgments. The first method appears to be inappropriate for investigating correspondence. The correlations are rather unstable because of the small number of attributes, and apart from that, they tend to underestimate real correspondence when the weights in the respective sets are approximately equal. The second method shows that the three sets of weights are about equally adequate in predicting the actual subject judgments. It is concluded that this method convincingly demonstrates that the three different ways of eliciting attribute weights yield similar results.     

How the Thatcher illusion reveals evolutionary differences in the face processing of primates

Face recognition in humans is a complex cognitive skill that requires sensitivity to unique configurations of eyes, mouth, and other facial features. The Thatcher illusion has been used to demonstrate the importance of orientation when processing configural information within faces. Transforming an upright face so that the eyes and mouth are inverted renders the face grotesque; however, when this “Thatcherized” face is inverted, the effect disappears. Due to the use of primate models in social cognition research, it is important to determine the extent to which specialized cognitive functions like face processing occur across species. To date, the Thatcher illusion has been explored in only a few species with mixed results. Here, we used computerized tasks to examine whether nonhuman primates perceive the Thatcher illusion. Chimpanzees and rhesus monkeys were required to discriminate between Thatcherized and unaltered faces presented upright and inverted. Our results confirm that chimpanzees perceived the Thatcher illusion, but rhesus monkeys did not, suggesting species differences in the importance of configural information in face processing. Three further experiments were conducted to understand why our results differed from previously published accounts of the Thatcher illusion in rhesus monkeys.     

Framing effects and the reversed Müller-Lyer illusion.

The enclosure hypothesis of the reversed Müller-Lyer illusion was examined in three experiments. In Experiment 1, the ingoing- and outgoing-wings forms of the illusion were measured separately, as a function of the size of the gap between the ends of the shaft and the apices of the wings. In Experiments 2 and 3, the effects of a square frame and of complete and amputated versions of a rectangle on the perceived length of an enclosed horizontal line were examined. For all non-Müller-Lyer illusion figures, an inverted U-shaped function describes the relationship between illusion magnitude and the length of the test line. The peak overestimation of the test line's length was obtained when the ratio of total figure length to test line length was about 3:2. Taken together, the results of the three experiments suggest that the reversed Müller-Lyer illusion can be explained within current theoretical frameworks, such as assimilation theory, without recourse to a special factor of enclosure.     

Three-dimensional Müller-Lyer illusion

Three-dimensional (3-D) variants of the Müller-Lyer pattern were created to address the question of where along the path of information flow in the visual system the illusion might occur. These variants, which yielded a robust illusion, included dihedral angles in place of the arrowheads of the classical pattern. The enormous difference in the shape of the resulting retinal image, compared with that of the classical pattern, makes it difficult to explain the present illusion by resorting to image-processing theories such as selective filtering (Ginsburg, 1984, 1986) or depth processing (Gregory, 1963, 1966, 1968). It was also shown that this 3-D illusion is homologous with the classical illusion, and that the two may thus share a common causal mechanism. A new type of 3-D figure, which yielded the same retinal image as did the classical pattern, was then employed. However, since the figure was 3-D, its shape in spatial coordinates was very different compared to that of the classical pattern. The magnitude of the illusion obtained with this figure was half that of the classical pattern. This finding suggests that the illusion might be caused by processes that occur after the computation of depth. All three experiments indicated that the illusion may be produced later in the processing stream than has previously been suggested.     

A variant of the anomalous motion illusion based upon contrast and visual latency

We examined a variant of the anomalous motion illusion. In a series of experiments, we ascertained luminance contrast to be the critical factor. Low-contrast random dots showed longer latency than high-contrast ones, irrespective of whether they were dark or light (experiments 1 -3). We conjecture that this illusion may share the same mechanism with the Hess effect, which is characterised by visual delay of a low-contrast, dark stimulus in a moving situation. Since the Hess effect is known as the monocular version of the Pulfrich effect, we examined whether illusory motion in depth could be observed if a high-contrast pattern was projected to one eye and the same pattern of low-contrast was presented to the other eye, and they were binocularly fused and swayed horizontally. Observers then reported illusory motion in depth when the low-contrast pattern was dark, but they did not when it was bright (experiment 4). Possible explanations of this inconsistency are discussed.     

集中和分散注意对多感觉整合中听觉主导效应的影响

听觉主导效应是指多感觉通道信息整合过程中,听觉通道中的信息得到优先加工,从而主导其他感觉通道的信息。研究采用经典的声音诱发闪光错觉的范式,通过两个实验操纵了注意资源的分配方式以及实验任务难度,考察了主动注意听觉通道的声音刺激对声音诱发闪光错觉产生的影响,以及任务难度对声音诱发闪光错觉的影响。结果发现:(1)裂变错觉会受到注意资源分配程度的影响,但是融合错觉则不然;(2)任务难度既不会影响裂变错觉,也不会影响融合错觉。说明了分散注意能够影响听觉主导效应中的裂变错觉,并且这种主导效应与任务难度无关。     

Utilization of covariation knowledge in source monitoring: no evidence for implicit processes

In three experiments, a "hidden covariation" (Lewicki, in Journal of Experimental Psychology: Learning, Memory, and Cognition, 12, 135-146, 1986) of nonsalient stimulus attributes and the source of stimulus information was established to test whether implicit knowledge about this correlation influences source memory judgments. The source monitoring framework (Johnson, Hashtroudi, and Lindsay, in Psychological Bulletin, 114, 3-28, 1993) postulates heuristic and strategic judgment processes in source attributions. A multinomial model analysis disentangled memory and guessing processes. While there were large strategic guessing biases involving explicit knowledge in all experiments, there was no evidence for the use of implicit covariation knowledge. Only participants who were later able to verbalize the covariation had shown corresponding biases during the source memory test, suggesting that implicit covariation knowledge plays no prominent role in the reconstruction processes in source monitoring.     

Apparent equivalence between perception and imagery in the production of various visual illusions

The ability of high and low imagers (as assessed by the Vividness of Visual Imagery Questionnaire) to utilize imagery in the production of a visual illusion was examined in three experiments. In Experiment 1, subjects were to imagine noninducing elements oi the Ponzo figure. In Experiment 2, subjects were asked to imagine the inducing angle of the Ponzo figure. Subjects were requested to imagine the inducing diagonals of the Hering and Wundt figures in Experiment 3. Regardless of which figure was presented, high imagers consistently reported an illusion whether it was produced by real or imagined lines. Also, the imagery-produced illusion was equivalent in magnitude to the actual illusion (when all lines are physically present). Low imagers reported an illusion only when lines were physically present. These results were interpreted in terms of Finke’s (1980) equivalence theory.     

Altering Mueller-Lyer illusion magnitude using figural additions at the wing-shaft intersections

The Mueller-Lyer (ML) illusion has been used to study the way in which perceived length is affected by processes of information extraction when a visual target of interest (the ML shaft) is surrounded by other nontarget figural elements (inward-or outward-turning wings). It is argued that the perception of length is computed in terms of the center of gravity or centroid of figural elements at the wing-shaft intersection. The outward-turning wings shift the computational centroid away from the shaft end, giving rise to an erroneous overestimation of shaft length, while the inward-turning wings have the opposite effect. In three experiments, we observed that figural changes, which theoretically shifted the center of gravity of figural elements at the wing-shaft intersection, also increased or decreased the magnitude of the ML illusion.     

Framing effects and the reversed Müller-Lyer illusion

The enclosure hypothesis of the reversed Müller-Lyer illusion was examined in three experiments. In Experiment 1, the ingoing- and outgoing-wings forms of the illusion were measured separately, as a function of the size of the gap between the ends of the shaft and the apices of the wings. In Experiments 2 and 3, the effects of a square frame and of complete and amputated versions of a rectangle on the perceived length of an enclosed horizontal line were examined, For all non-Müller-Lyer illusion figures, an inverted U-shaped function describes the relationship between illusion magnitude and the length of the test line. The peak overestimation of the test line’s length was obtained when the ratio of total figure length to test line length was about 3:2. Taken together, the results of the three experiments suggest that the reversed Müller-Lyer illusion can be explained within current theoretical frameworks, such as assimilation theory, without recourse to a special factor of enclosure.