New motion illusion caused by pictorial motion lines

Motion lines (MLs) are a pictorial technique used to represent object movement in a still picture. This study explored how MLs contribute to motion perception. In Experiment 1, we reported the creation of a motion illusion caused by MLs: random displacements of objects with MLs on each frame were perceived as unidirectional global motion along the pictorial motion direction implied by MLs. In Experiment 2, we showed that the illusory global motion in the peripheral visual field captured the perceived motion direction of random displacement of objects without MLs in the central visual field, and confirmed that the results in Experiment 1 did not stem simply from response bias, but resulted from perceptual processing. In Experiment 3, we showed that the spatial arrangement of orientation information rather than ML length is important for the illusory global motion. Our results indicate that the ML effect is based on perceptual processing rather than response bias, and that comparison of neighboring orientation components may underlie the determination of pictorial motion direction with MLs.     

Immediacy bias in social-emotional comparisons

In seven studies of naturally occurring, "real-world" emotional events, people demonstrated an immediacy bias in social-emotional comparisons, perceiving their own current or recent emotional reactions as more intense compared with others' emotional reactions to the same events. The events examined include crossing a scary bridge (study 1a), a national tragedy (study 1b), terrorist attacks (studies 2a and 3b), a natural disaster (study 2b), and a presidential election (study 3b). These perceived differences between one's own and others' emotions declined over time, as relatively immediate and recent emotions subsided, a pattern that people were not intuitively aware of (study 2c). This immediacy bias in social-emotional comparisons emerged for both explicit comparisons (studies 1a, 1b, and 3b), and for absolute judgments of emotional intensity (studies 2a, 2b, and 3a). Finally, the immediacy bias in social-emotional comparisons was reduced when people were reminded that emotional display norms might lead others' appearances to understate emotional intensity (studies 3a and 3b). Implications of these findings for social-emotional phenomena are discussed.     

The sound of the crowd: auditory information modulates the perceived emotion of a crowd based on bodily expressions

Although both auditory and visual information can influence the perceived emotion of an individual, how these modalities contribute to the perceived emotion of a crowd of characters was hitherto unknown. Here, we manipulated the ambiguity of the emotion of either a visual or auditory crowd of characters by varying the proportions of characters expressing one of two emotional states. Using an intersensory bias paradigm, unambiguous emotional information from an unattended modality was presented while participants determined the emotion of a crowd in an attended, but different, modality. We found that emotional information in an unattended modality can disambiguate the perceived emotion of a crowd. Moreover, the size of the crowd had little effect on these crossmodal influences. The role of audiovisual information appears to be similar in perceiving emotion from individuals or crowds. Our findings provide novel insights into the role of multisensory influences on the perception of social information from crowds of individuals.     

Narrative analysis in developmental social and linguistic pathologies: dissociation between emotional and informational language use

This study examined the use of emotional and informational aspects of language in populations that demonstrate developmental social-emotional and linguistic pathologies. We tested high-functioning autistic (HFA) individuals because this group reveals deficiencies in social-emotional and informative aspects of language as well as abnormalities in sociability. We tested Williams syndrome (WS) individuals because of the claim that the social-emotional aspects of language use and sociability are differentially preserved in the context of mental retardation. We compared the performance of these two groups with two groups of control children (7- and 11-year-olds). All of the participants viewed a slide show depicting an event and were asked to retell the story. These narratives were coded for emotional and informational elements. The results showed that on measures of emotional elements, the WS group patterned with the control groups and only the HFA participants received lower scores, while on the informational elements, the two pathological groups did not differ, and both were lower than the controls. The results suggest that the preservation of language among WS individuals is specific for the emotional aspects of language.     

A double dissociation between action and perception in the context of visual illusions: opposite effects of real and illusory size

The idea that there are two distinct cortical visual pathways, a dorsal action stream and a ventral perception stream, is supported by neuroimaging and neuropsychological evidence. Yet there is an ongoing debate as to whether or not the action system is resistant to pictorial illusions in healthy participants. In the present study, we disentangled the effects of real and illusory object size on action and perception by pitting real size against illusory size. In our task, two objects that differed slightly in length were placed within a version of the Ponzo illusion. Even though participants erroneously perceived the physically longer object as the shorter one (or vice versa), their grasping was remarkably tuned to the real size difference between the objects. These results provide the first demonstration of a double dissociation between action and perception in the context of visual illusions and together with previous findings converge on the idea that visually guided action and visual perception make use of different metrics and frames of reference.     

Influence of visually induced expectation on perceived motor effort: A visual-proprioceptive interaction at the Santa Cruz Mystery Spot

It is known that dense objects seem heavier than larger, less dense objects of the same weight. We have investigated a related illusion, in which visual context biases the apparent weight of a single object. The apparatus is a cabin on a steep hillside near Santa Cruz, CA, tilted 17° from vertical. From its ceiling hangs a weight on a chain. The cabin’s tilt makes the weight appear suspended at an angle. Pushing the weight toward the visually based vertical is perceived as difficult, whereas pushing it away from the visual vertical is perceived as easy. Seven subjects pushed the weight in both directions, judging required effort on a double-anchored 1–10 scale. All experienced the effort illusion, with no significant subject effect. When subjects’ eyes were closed, the effect was smaller but still present. Apparently proprioceptive and skin inputs, equal for both directions, are ignored or underweighted as visually based expectations influence perceived effort.     

The rubber pencil illusion

When a straight, rigid line segment is put into certain types of motion, it appears to an observer to lose its rigidity and become rubbery, as in the well-known “rubber pencil illusion.“ The factors controlling this illusion were examined, including the nature of the motion employed (harmonic or linear oscillation), the amplitudes of the translational and rotational components of the motion, and the phase relationship between these two components. The effect is shown to be due to visual persistence. The status of the illusion as a potential counterexample to the rigidity principle (that moving, two-dimensional arrays will be perceived as rigid) is discussed.     

Do domestic dogs (<Emphasis Type="Italic">Canis lupus familiaris</Emphasis>) perceive the Delboeuf illusion?

In the last decade, visual illusions have been repeatedly used as a tool to compare visual perception among species. Several studies have investigated whether non-human primates perceive visual illusions in a human-like fashion, but little attention has been paid to other mammals, and sensitivity to visual illusions has been never investigated in the dog. Here, we studied whether domestic dogs perceive the Delboeuf illusion. In human and non-human primates, this illusion creates a misperception of item size as a function of its surrounding context. To examine this effect in dogs, we adapted the spontaneous preference paradigm recently used with chimpanzees. Subjects were presented with two plates containing food. In control trials, two different amounts of food were presented in two identical plates. In this circumstance, dogs were expected to select the larger amount. In test trials, equal food portion sizes were presented in two plates differing in size: if dogs perceived the illusion as primates do, they were expected to select the amount of food presented in the smaller plate. Dogs significantly discriminated the two alternatives in control trials, whereas their performance did not differ from chance in test trials with the illusory pattern. The fact that dogs do not seem to be susceptible to the Delboeuf illusion suggests a potential discontinuity in the perceptual biases affecting size judgments between primates and dogs.     

Combined visual illusion effects on the perceived index of difficulty and movement outcomes in discrete and continuous fitts’ tapping

The speed-accuracy trade-off is a fundamental movement problem that has been extensively investigated. It has been established that the speed at which one can move to tap targets depends on how large the targets are and how far they are apart. These spatial properties of the targets can be quantified by the index of difficulty (ID). Two visual illusions are known to affect the perception of target size and movement amplitude: the Ebbinghaus illusion and Muller-Lyer illusion. We created visual images that combined these two visual illusions to manipulate the perceived ID, and then examined people’s visual perception of the targets in illusory context as well as their performance in tapping those targets in both discrete and continuous manners. The findings revealed that the combined visual illusions affected the perceived ID similarly in both discrete and continuous judgment conditions. However, the movement outcomes were affected by the combined visual illusions according to the tapping mode. In discrete tapping, the combined visual illusions affected both movement accuracy and movement amplitude such that the effective ID resembled the perceived ID. In continuous tapping, none of the movement outcomes were affected by the combined visual illusions. Participants tapped the targets with higher speed and accuracy in all visual conditions. Based on these findings, we concluded that distinct visual-motor control mechanisms were responsible for execution of discrete and continuous Fitts’ tapping. Although discrete tapping relies on allocentric information (object-centered) to plan for action, continuous tapping relies on egocentric information (self-centered) to control for action. The planning-control model for rapid aiming movements is supported.     

Visual illusions affect both movement planning and on-line control: a multiple cue position on bias and goal-directed action

Over the last decade, there has been an interest in the impact of visual illusions on the control of action. Much of this work has been motivated by Milner and Goodale's two visual system model of visual processing. This model is based on a hypothesized dissociation between cognitive judgments and the visual control of action. It holds that action is immune to the visual context that provides the basis for the illusion-induced bias associated with cognitive judgments. Recently, Glover has challenged this position and has suggested that movement planning, but not movement execution is susceptible to visual illusions. Research from our lab is inconsistent with both models of visual-motor processing. With respect to the planning and control model, kinematic evidence shows that the impact of an illusion on manual aiming increases as the limb approaches the target. For the Ebbinghaus illusion, this involved a decrease in the time after peak velocity to accommodate the 'perceived' size of the target. For the Müller-Lyer illusion, the influence of the figure's tails increased from peak velocity to the end of the movement. Although our findings contradict a strong version of the two visual systems hypothesis, we did find dissociations between perception and action in another experiment. In this Müller-Lyer study, perceptual decisions were influenced by misjudgment of extent, while action was influenced by misjudgment of target position. Overall, our findings are consistent with the idea that it is often necessary to use visual context to make adjustments to ongoing movements.     

Varieties of Pictorial Illusion

This article focuses on a potentially perplexing aspect of our interactions with pictorial representations (including film, paintings, pictures, drawings, photographs, even video games): in some cases, it seems that visual representations can play tricks on our cognitive faculties. We may either come to believe that objects represented in pictures are real or perhaps perceive them as such. The possibility of widespread pictorial illusions has been oft discussed, and discarded, in the aesthetics literature. I support this stance. However, the nature of the illusion is more complicated than is usually considered. I argue that there are five different types of potential illusions and present reasons for rejecting each. I also explore in detail the most persistent illusion: the “object recognition perceptual illusion thesis,” which states that we undergo a perceptual illusion while viewing pictorial representations simply in virtue of seeing objects in the representation. I contend that a rejection of this thesis depends on the nature of perceptual content, an issue with far‐reaching consequences in aesthetics.     

Perception of the Ponzo illusion by rhesus monkeys, chimpanzees, and humans: Similarity and difference in the three primate species

In Experiment 1, 3 rhesus monkeys and 1 chimpanzee were tested for their susceptibility to the Ponzo illusion. The subjects were first trained to report the length of the target bar presented at the center of the computer display by touching either of the two choice locations designated as “long” or “short.” When inverted-V context lines were superimposed on the target bar, the subjects tended to report “long” more often as the apex of these upward-converging lines approached the target bar. The perception of the Ponzo illusion was thus demonstrated. In Experiment 2, the same 3 rhesus monkeys and 2 new chimpanzees were tested using two types of context lines that provided different strengths of linear perspective. The subjects showed a bias similar to that found in Experiment 1, but there was no difference in the magnitude of the bias between the two types of context in either species. This failed to support the classic account for the Ponzo illusion, the perspective theory, raised by Gregory (1963). In Experiment 3, the magnitude of the illusion was compared between the inverted-V context and the context consisting of short vertical lines having the same gap as the former in the same 3 rhesus monkeys and 2 of the chimpanzees from the preceding experiments. While the chimpanzees showed the illusion for both types of stimuli, the monkeys showed no illusion for the latter. In Experiment 4, 6 humans were tested in a comparable procedure. As in the nonhuman primates, the illusion was unaffected by the strength of linear perspective. On the other hand, the humans showed considerably larger illusion for the context consisting of vertical lines than for contexts consisting of converging lines. Thus, there was a great species difference in the effect of the gap itself on the magnitude of the Ponzo illusion. Similarity found at first turned out to be no more than superficial. Possible sources of this species difference are discussed.     

The Mystery Spot Illusion and its Relation to Other Visual Illusions

Observations at The Mystery Spot, a roadside attraction near Santa Cruz, California, suggest intriguing visual illusions based on tilt-induced effects. Specifically, a tilted spatial background at The Mystery Spot induced misperceptions of the orientation of the cardinal axes (i.e., true horizontal and vertical), which then led to illusions in the perceived height of twoindividuals. This illusion was assessed at The Mystery Spot and replicated in the laboratory using pictorial and lined displays rotated in the picture plane. These findings are described in terms of the orientation framing theory, which suggests that these and other tilt-induced illusions (e.g., Ponzo illusion, Zöllner illusion) can be attributed to distorted frames of reference.     

Visual and haptic perception of the horizontal-vertical illusion

The horizontal-vertical illusion consists of two lines of the same length (one horizontal and the other vertical) at a 90 degree angle from one another forming either an inverted-T or an L-shape. The illusion occurs when the length of a vertical line is perceived as longer than the horizontal line even though they are the same physical length. The illusion has been shown both visually and haptically. The present purpose was to assess differences between the visual or haptic perception of the illusions and also whether differences occur between the inverted-T and the L-shape illusions. The current study showed a greater effect in the haptic perception of the horizontal-vertical illusion than in visual perception. There is also greater illusory susceptibility of the inverted-T than the L-shape.     

情绪背景对面部表情识别的影响及其作用机制

正确识别面部表情对成功的社会交往有重要意义。面部表情识别受到情绪背景的影响。本文首先介绍了情绪背景对面部表情识别的增强作用,主要表现为视觉通道的情绪一致性效应和跨通道情绪整合效应;然后介绍了情绪背景对面部表情识别的阻碍作用,主要表现为情绪冲突效应和语义阻碍效应;接着介绍了情绪背景对中性和歧义面孔识别的影响,主要表现为背景的情绪诱发效应和阈下情绪启动效应;最后对现有研究进行了总结分析,提出了未来研究的建议。     

A scaling analysis of the snake lightness illusion

Logvinenko and Maloney (2006) measured perceived dissimilarities between achromatic surfaces placed in two scenes illuminated by neutral lights that could differ in intensity. Using a novel scaling method, they found that dissimilarities between light surface pairs could be represented as a weighted linear combination of two dimensions, "surface lightness" (a perceptual correlate of the difference in the logarithm of surface albedo) and "surface brightness" (which corresponded to the differences of the logarithms of light intensity across the scenes). Here we attempt to measure the contributions of these dimensions to a compelling lightness illusion (the "snake illusion"). It is commonly assumed that this illusion is a result of erroneous segmentation of the snake pattern into regions of unequal illumination. We find that the illusory shift in the snake pattern occurs along the surface lightness dimension, with no contribution from surface brightness. Thus, even if an erroneous segmentation of the snake pattern into strips of unequal illumination does happen, it reveals itself, paradoxically, as illusory changes in surface lightness rather than as surface brightness. We conjecture that the illusion strength depends on the balance between two groups of illumination cues signaling the true (uniform) illumination and the pictorial (uneven) illumination.     

Reflections on the hand: the use of a mirror highlights the contributions of interpreted and retinotopic representations in the rubber-hand illusion

In the rubber-hand illusion, observing a rubber hand stroked in synchrony with one's own hand results in mislocalisation of the own hand, which is perceived as being located closer to the rubber hand. This illusion depends on having the rubber hand placed at a plausible egocentric orientation with respect to the observer. In the present study, we took advantage of this finding in order to compare the relative influence on the illusion of the rubber hand's perceived retinotopic image against its real-world position. The rubber hand was positioned egocentrically (fingers away from the participant) or allocentrically (fingers towards the participant), while participants viewed it either directly or via a mirror that was placed facing the participant. In the mirror conditions, the orientation of the retinotopic image of the hand (either egocentric or allocentric) was opposed to its real-world orientation. We found that the illusion was elicited in both mirror conditions, to roughly the same extent. Thus either of two representations can elicit the rubber-hand illusion: a world-centred understanding of the scene, resulting from the inferred position of the hand based on its mirror reflection, or a purely visual retinotopic representation of the viewed hand. In the mirror conditions, the illusion was somewhat weaker than in the typical directly viewed egocentric condition. We attribute this to competition between two incompatible representations introduced by the presence of the mirror. Finally, in two control experiments we ruled out that this reduction was due to two properties of mirror reflections: the increased perceived distance of items and the reversal of the apparent handedness of the rubber hand.     

情感预测中的聚焦错觉

聚焦错觉是个体在进行情感预测时,错误地估计了聚焦事件会对情绪造成影响的一种倾向.聚焦错觉是造成情感预测偏差的重要原因.其心理机制主要包括直觉预测和可得性模型.聚焦错觉的影响因素主要有预测事件的情感效价、性质,情境因素、个体习惯和文化差异等.其应对策略主要有去焦点化和情感平均.未来的研究应从聚焦错觉与忽视情绪适应的关系、聚焦错觉的产生根源以及聚焦错觉与其他聚焦效应的关系等方面来进一步探讨.     

Biological movements look uniform: evidence of motor-perceptual interactions.

Six experiments demonstrate a visual dynamic illusion. Previous work has shown that in 2-dimensional (2D) drawing movements, tangential velocity and radius of curvature covary in a constrained manner. The velocity of point stimuli is perceived as uniform if and only if this biological constraint is satisfied. The illusion is conspicuous: The variations of velocity in the stimuli exceed 200%. Yet movements are perceived as uniform. Conversely, 2D stimuli moving at constant velocity are perceived as strongly nonuniform. The illusion is robust: Exposure to true constant velocity fails to suppress it. Results cannot be explained entirely by the kinetic depth effect. The illusion is evidence of a coupling between motor and perceptual processes: Even in the absence of any intention to perform a movement, certain properties of the motor system implicitly influence perceptual interpretation of the visual stimulus.     

The duration of a brief event in the mind's eye.

A new illusion of perceived duration associated with focused spatial attention is reported. Brief flashes in attended locations were perceived to last longer than the same flashes in unattended locations. That illusion was shown to be completely independent of another illusion concerning the perceived onset of a flash, ruling out the possibility that the effect on perceived duration is derivative of a comparison between perceived onset and offset. The illusion also occurred when the event duration was composed of a temporal gap rather than a brief flash, ruling out low-level visible persistence as a basis for the illusion. Taken together, the results point to cortical connections from higher brain centers' both speeding and prolonging the visual signals occurring in lower sensory regions. Those temporal consequences could easily subserve many of the perceptual benefits ascribed to attention for spatial and intensive properties.