Rotation of objects in pictures viewed at an angle: evidence for different properties of two types of pictorial space

As an observer views a picture from different viewing angles, objects in the picture appear to change orientation relative to the observer, but some objects change orientation more than others. This difference in rotation for different objects is called the differential rotation effect. The differential rotation is not, however, accompanied by corresponding changes in the perception of the spatial layout of objects in the picture. This lack of correspondence between the perception of rotation and the perception of spatial layout is a result of the fact that the information on a picture's surface defines two kinds of pictorial space with different properties. Rotation is perceived in terms of the pictorial space outside the picture, and spatial layout is perceived in terms of the pictorial space inside the picture.     

Temporal shifts in eye gaze and facial expressions independently contribute to the perceived attractiveness of unfamiliar faces

ABSTRACT

We investigated whether attractiveness ratings of expressive faces would be affected by gaze shifts towards or away from the observer. In all experiments, effects of facial expression were found, with higher attractiveness ratings to positive over negative expressions, irrespective of effects of gaze-shifts. In the first experiment faces with gaze shifts away from the observer were preferred. However, when the dynamics of the gaze shift was disrupted, by adding an intermediate delay, the effect of direction of gaze shift disappeared. By manipulating the relative duration of each gaze direction during a gaze shift we found higher attractiveness ratings to faces with a longer duration of direct gaze, particularly in the initial exposure to a face. Our findings suggest that although the temporal dynamics of eye gaze and facial expressions influence the aesthetic evaluation of faces, these cues appear to act independently rather than in an integrated manner for social perception.     

威胁相关面孔表情对眼睛注视方向知觉的影响

以往研究发现眼睛注视方向知觉受面孔表情的影响,愤怒面孔相较于恐惧面孔更倾向被判断为看着观察者。虽然研究者对此提出了不同的解释,但目前尚不清楚愤怒和恐惧表情在注视方向知觉中的这种差异影响到底来自于面孔的结构信息还是物理特征信息。本研究采用注视方向辨别任务,计算直视知觉范围（The Cone of Direct Gaze,CoDG）为因变量,分别以直立,倒置及模糊图片为实验材料,试图通过分离面孔结构信息和物理特征信息,对以上问题进行探讨。结果发现在保留面孔全部信息的情况下（实验1）愤怒面孔的CoDG大于恐惧面孔;在破坏结构信息加工,只保留特征信息加工的情况下（实验2））愤怒和恐惧表情在直视知觉范围上的差异消失了;在削弱物理特征信息加工,保留结构信息加工的情况下（实验3）二者在CoDG上的差异又复现。本研究结果说明不同威胁性面孔表情对眼睛注视知觉的影响主要来自于二者在与情绪意义相关的结构信息加工上的不同,而二者非低级的物理信息上的差异,支持信号共享假说和情绪评价假说对威胁性面孔表情与注视方向整合加工解释的理论基础。     

Spatial layout, orientation relative to the observer, and perceived projection in pictures viewed at an angle

Judgments of the spatial layout of a three-dimensional array of pictured dowels remain relatively constant as viewing angle changes, whereas judgments of their orientation relative to the observer (perceived orientation) vary. These changes in perceived orientation as viewing angle changes, called the differential rotation effect (DRE), also occur for stimuli such as the eyes in portraits, which are not extended in pictorial space. Thus, the mechanism for the DRE does not depend on the extension of pictured objects in depth. The DRE is decreased when back-illuminated pictures are viewed in the dark so that the picture plane is not visible. This result suggests that the DRE depends on information that defines a pictured object's direction relative to the picture plane. The difference in the way spatial layout and perceived orientation are affected by changes in viewing angle suggests that it is important to distinguish between these two attributes of pictures. In addition, another attribute, the picture's projection, should be distinguished from spatial layout and perceived orientation. When these distinctions are not made, the result is confusion, particularly when discussing whether or not pictures viewed at an angle appear distorted.     

The Mona Lisa effect: is 'our' Lisa fame or fake?

This demonstration uses one of the most famous human faces, the portrait of Mona Lisa, La Gioconda, by Leonardo da Vinci. Usually, we have a very accurate and stable representation of the exact configuration of such a familiar face. Typically, we are able to rapidly recognise even subtle configural changes. However, here we show that an exposure to specific alterations performed on a familiar face substantially reduces this ability even over a time period as long as 80 min. This demonstration illustrates the flexibility of the perceptual system and adaptation to new information.     

Foreshortened tiles in paths converging on an observer viewing a picture: Elevation and visual angle ratio determine perceived size

Observers were shown wide-angle pictures of tiles on a ground plane and were asked about the aspect ratios of the tiles. The observers viewed the pictures from a fixed center of projection. Some of the tiles were in a path coming straight toward the observer. In one picture, the path came from the center of the picture, and in two others the path came from the left side of the picture (one from 30° and one from 45° to the left of the center, from the observer’s point of view). The apparent aspect ratios were a function of the elevations of the tiles and the ratios of visual angles of the sides of the tiles. Judgments were identical for all three paths. The local slant of the picture surface was not a significant factor.     

Looking at perspective pictures from too far, too close, and just right

A central problem for psychology is vision's reaction to perspective. In the present studies, observers looked at perspective pictures projected by square tiles on a ground plane. They judged the tile dimensions while positioned at the correct distance, farther or nearer. In some pictures, many tiles appeared too short to be squares, many too long, and many just right. The judgments were strongly affected by viewing from the wrong distance, eye height, and object orientation. The authors propose a 2-factor angles and ratios together (ART) theory, with the following factors: the ratio of the visual angles of the tile's sides and the angle between (a) the direction to the tile from the observer and (b) the perpendicular, from the picture plane to the observer, that passes through the central vanishing point.     

Biases in visual orienting to negative and positive scenes in dysphoria: An eye movement study

The study investigated biases for negative information in component processes of visual attention (initial shift vs. maintenance of gaze) in dysphoric and nondysphoric individuals. Eye movements were recorded while participants viewed a series of picture pairs depicting negative, positive, and neutral scenes (each pair presented for 3 s). Biases in initial orienting were assessed from the direction and latency of the initial shift in gaze, whereas biases in the maintenance of attention were assessed from the duration of gaze on the picture that was initially fixated. Results indicated that the dysphoric group showed a significantly greater bias to maintain gaze longer on negative pictures, relative to control pictures, compared with the nondysphoric group. There was no evidence of a dysphoria-related bias in initial shift of orienting to negative cues. Results are consistent with a depression-related bias that operates in the maintenance of attention on negative material.     

Vigilance and Avoidance of Threat in the Eye Movements of Children with Separation Anxiety Disorder

The vigilance-avoidance attention pattern is found in anxious adults, who initially gaze more at threatening pictures than nonanxious adults (vigilance), but subsequently gaze less at them than nonanxious adults (avoidance). The present research, using eye tracking methodology, tested whether anxious children show the same pattern. Children with separation anxiety disorder or no mental disorder viewed pairs of pictures, while the direction of their gaze was tracked. Each picture pair showed one picture of a woman separating from a child, the other picture of a woman reuniting with a child. The results supported the vigilance-avoidance model in children. Although the two groups’ gaze direction did not differ during the first second of viewing, anxious children gazed significantly more at separating (threatening) pictures than nonanxious children after a period of 1 s. But after 3 s the pattern reversed: anxious children gazed significantly less at the separating pictures than nonanxious children.     

The effect of gaze on gaze direction while looking at art

In highly controlled cuing experiments, conspecific gaze direction has powerful effects on an observer’s attention. We explored the generality of this effect by using paintings in which the gaze direction of a key character had been carefully manipulated. Our observers looked at these paintings in one of three instructional states (neutral, social, or spatial) while we monitored their eye movements. Overt orienting was much less influenced by the critical gaze direction than what the cuing literature might suggest: An analysis of the direction of saccades following the first fixation of the critical gaze showed that observers were weakly biased to orient in the direction of the gaze. Over longer periods of viewing, however, this effect disappeared for all but the social condition. This restriction of gaze as an attentional cue to a social context is consistent with the idea that the evolution of gaze direction detection is rooted in social communication. The picture stimuli from this experiment can be downloaded from the Psychonomic Society’s Archive of Norms, Stimuli, and Data, www.psychonomic.org/archive.     

Talking heads or talking eyes? Effects of head orientation and sudden onset gaze cues on attention capture

The direction of gaze towards or away from an observer has immediate effects on attentional processing in the observer. Previous research indicates that faces with direct gaze are processed more efficiently than faces with averted gaze. We recently reported additional processing advantages for faces that suddenly adopt direct gaze (abruptly shift from averted to direct gaze) relative to static direct gaze (always in direct gaze), sudden averted gaze (abruptly shift from direct to averted gaze), and static averted gaze (always in averted gaze). Because changes in gaze orientation in previous study co-occurred with changes in head orientation, it was not clear if the effect is contingent on face or eye processing, or whether it requires both the eyes and the face to provide consistent information. The present study delineates the impact of head orientation, sudden onset motion cues, and gaze cues. Participants completed a target-detection task in which head position remained in a static averted or direct orientation while sudden onset motion and eye gaze cues were manipulated within each trial. The results indicate a sudden direct gaze advantage that resulted from the additive role of motion and gaze cues. Interestingly, the orientation of the face towards or away from the observer did not influence the sudden direct gaze effect, suggesting that eye gaze cues, not face orientation cues, are critical for the sudden direct gaze effect.     

Cognitive impenetrability of memory for orientation

This research produced evidence that an aspect of visual long-term memory--memory for lateral orientation of pictures--is constrained by a viewer-centered or egocentric reference frame. Subjects in Experiment 1 verbally encoded and then verbally recalled the locations of objects within scenic pictures. Recall of locations in terms of left-right directions (using a viewer-centered frame) exceeded recall of locations in terms of relative proximities to features of the room (using an environmental frame), even if the relative proximities had been verbalized at input. Subjects in Experiment 2 viewed half of a list of pictures directly and the remainder, reflected in a mirror. They then took a test in which they classified old pictures--all viewed directly--as "same-orientation" or "reversed". Performance was much better with a viewer-centered definition of same orientation (Does the picture appear the same way around?) than with an environmental definition (Is the picture the same way around on the screen?), even with forewarning of an environmental orientation test.     

Viewpoint and orientation influence picture recognition in the blind

In the first three experiments, subjects felt solid geometrical forms and matched raised-line pictures to the objects. Performance was best in experiment 1 for top views, with shorter response latencies than for side views, front views, or 3-D views with foreshortening. In a second experiment with blind participants, matching accuracy was not significantly affected by prior visual experience, but speed advantages were found for top views, with 3-D views also yielding better matching accuracy than side views. There were no performance advantages for pictures of objects with a constant cross section in the vertical axis. The early-blind participants had lower performance for side and frontal views. The objects were rotated to oblique orientations in experiment 3. Early-blind subjects performed worse than the other subjects given object rotation. Visual experience with pictures of objects at many angles could facilitate identification at oblique orientations. In experiment 5 with blindfolded sighted subjects, tangible pictures were used as targets and as choices. The results yielded superior overall performance for 3-D views (mean, M = 74% correct) and much lower matching accuracy for top views as targets (M = 58% correct). Performance was highest when the target and matching viewpoint were identical, but 3-D views (M = 96% correct) were still far better than top views. The accuracy advantage of the top views also disappeared when more complex objects were tested in experiment 6. Alternative theoretical implications of the results are discussed.     

Sex,skull length,breed, and age predict how dogs look at faces of humans and conspecifics

The gaze of other dogs and humans is informative for dogs, but it has not been explored which factors predict face-directed attention. We used image presentations of unfamiliar human and dog heads, facing the observer (portrait) or facing away (profile), and measured looking time responses. We expected dog portraits to be aversive, human portraits to attract interest, and tested dogs of different sex, skull length and breed function, which in previous work had predicted human-directed attention. Dog portraits attracted longer looking times than human profiles. Mesocephalic dogs looked at portraits longer than at profiles, independent of the species in the image. Overall, brachycephalic dogs and dogs of unspecified breed function (such as mixed breeds) displayed the longest looking times. Among the latter, females observed the images for longer than males, which is in line with human findings on sex differences in processing faces. In a subsequent experiment, we tested whether dog portraits functioned as threatening stimuli. We hypothesized that dogs will avoid food rewards or approach them more slowly in the presence of a dog portrait, but found no effect of image type. In general, older dogs took longer to approach food placed in front of the images and mesocephalic dogs were faster than dogs of other skull length types. The results suggest that short-headed dogs are more attentive to faces, while sex and breed function predict looking times through complex interactions.     

提取方式对相继记忆效应的影响

采用学习－测验（自由回忆和再认）研究范式和事件相关电位方法,研究图形的相继记忆效应（Dm效应）。14名大学生作为研究被试,根据其测验成绩将图片分为记住和未记住两类,对相应编码过程的ERPs进行分析。结果表明：⑴行为上,再认的平均击中率显著高于自由回忆;⑵脑电活动上,在刺激出现后400~700ms编码过程中记住项目的ERPs更正于未记住项目的ERPs;同时两种测验方式Dm效应的脑区分布不同,自由回忆主要分布在额区,再认主要分布在中央区和顶区,且在500~600ms自由回忆有左侧优势。这些结果表明,两种提取方式对Dm效应有不同的影响,这一结果预示自由回忆和再认的编码过程可能有不同的神经生理机制。     

Fooling the eyes: trompe l'oeil and reverse perspective

Trompe l'oeil pictures have been produced for hundreds of years. They attempt to create the impression of a surface that has different three-dimensional structure to the work; successful examples of trompe l'oeil typically constrain the observer's viewpoint and require use of a single eye. The works of Patrick Hughes are in relief but are painted to appear like conventional flat pictures; those parts that protrude from the picture plane are pictorially distant, or in reverse perspective. Movements of the observer result in fluid distortions of the pictorial image. These distortions occur with binocular observation and over a wide range of viewing distances.     

Emotions Evoked by Viewing Pictures may Affect Temporal Aspects of Visual Processing

We examined how impression (such as safety, pleasantness, and impact), as well as emotional arousal and valence, evoked by viewing a picture affects temporal resolution of visual processing and perceived picture duration. In the first experiment as an index of temporal resolution of visual processing, we measured the noticeable duration of a monochrome picture after presenting a color picture. In the second experiment, we measured the duration of the picture presentation, which was equivalent to the duration of the presentation of a gray rectangle that should not evoke specifically safe or pleasant impressions. We found that the minimum duration in which an observer could notice a monochrome image in viewing a dangerous picture was shorter than that in viewing safe pictures. We also found that observers overestimated the duration of the picture presentation in viewing dangerous pictures. However, there was no significant correlation between the results of the two experiments. These results suggest that the basis for improvement of the temporal resolution in visual processing differs from that for the elongation of the perceived duration.     

Are you looking at me? Measuring the cone of gaze

The processing of gaze cues plays an important role in social interactions, and mutual gaze in particular is relevant for natural as well as video-mediated communications. Mutual gaze occurs when an observer looks at or in the direction of the eyes of another person. The authors chose the metaphor of a cone of gaze to characterize this range of gaze directions that constitutes "looking at" another person. In 4 experiments using either a real person or a virtual head, the authors investigated the influences of observer distance, head orientation, visibility of the eyes, and the presence of a 2nd head on the perceived direction and width of the gaze cone. The direction of the gaze cone was largely affected by all experimental manipulations, whereas its angular width remained comparatively stable.     

Effects of perceived mutual gaze and gender on face processing and recognition memory

Perceived gaze contact in seen faces may convey important social signals. We examined whether gaze perception affects face processing during two tasks: Online gender judgement, and later incidental recognition memory. Individual faces were presented with eyes directed either straight towards the viewer or away, while these faces were seen in either frontal or three-quarters view. Participants were slower to make gender judgements for faces with direct versus averted eye gaze, but this effect was particularly pronounced for faces with opposite gender to the observer, and seen in three-quarters view. During subsequent surprise recognition-memory testing, recognition was better for faces previously seen with direct than averted gaze, again especially for the opposite gender to the observer. The effect of direct gaze was stronger in both tasks when the head was seen in three-quarters rather than in frontal view, consistent with the greater salience of perceived eye contact for deviated faces. However, in the memory test, face recognition was also relatively enhanced for faces of opposite gender in front views when their gaze was averted rather than direct. Together, these results indicate that perceived eye contact can interact with facial processing during gender judgements and recognition memory, even when gaze direction is task-irrelevant, and particularly for faces of opposite gender to the observer (an influence which controls for stimulus factors when considering observers of both genders). These findings appear consistent with recent neuroimaging evidence that social facial cues can modulate visual processing in cortical regions involved in face processing and memory, presumably via interconnections with brain systems specialized for gaze perception and social monitoring.     

The horizon-ratio relation as information for relative size in pictures

The horizon-ratio relation was found to be an effective source of information for relative size in pictures under some conditions: when the difference in image size of depicted “same real size” objects was not too great (Experiment 1), and when the horizon line was not too high or too low in the picture (Experiment 2). The latter finding seemed to be linked to the observers’ identification of the horizontal line as the horizon (and not as the edge of a finite surface). In addition, individual patterns of response were remarkably systematic even in the absence of a horizon, or any other pictorial information, (Experiment 3). It is suggested that in this case observers imposed a horizon on the picture on which to base their relative size judgments, possibly based on the observer’s own eye level or on the content of the picture. It is concluded that although the horizon-ratio relation provides the same kind of information as that available in the optic arrays from real scenes, pictorial information requires the satisfaction of additional constraints in order to be fully effective.