注视者及观察者因素对注视知觉的影响

注视知觉既包括识别他人对周围环境的注视位置, 也包括对他人是否在注视自己(即直视)的感知。诸多研究表明, 注视知觉过程受来自目光发出者与感知者多种因素的影响。从眼神沟通中不同角色角度出发, 将这些影响因素分为注视者因素和观察者因素。具体而言, 注视者因素主要探讨了眼部及头部物理特征及面孔情绪与吸引力对注视知觉的影响。而观察者因素则探讨了个体的心理或精神障碍、个体当前状态特征及观察者的性别、种族及文化差异对注视知觉的影响。未来研究可以从创新实验设计与任务出发, 探讨注视者刺激的实验材料与观察者特征的临床应用及跨文化差异等方面的问题。     

The positive and negative of human expertise in gaze perception

Judging where others look is crucial for many social and cognitive functions. Past accounts of gaze perception emphasize geometrical cues from the seen eye. Human eyes have a unique morphology, with a large white surround (sclera) to the dark iris that may have evolved to enhance gaze processing. Here we show that the contrast polarity of seen eyes has a powerful influence on gaze perception. Adult observers are highly inaccurate in judging gaze direction for images of human eyes with negative contrast polarity (regardless of whether the surrounding face is positive or negative), even though negative images of eyes preserve the geometric properties of positives that are judged accurately. The detrimental effect of negative contrast polarity is much larger for gaze perception than for other directional judgements (e.g. judging which way a head is turned). These results suggest an 'expert' system for gaze perception, which always treats the darker region of a seen eye as the part that does the looking.     

The look of love: gaze shifts and person perception

Gaze direction is a vital communicative channel through which people transmit information to each other. By signaling the locus of social attention, gaze cues convey information about the relative importance of objects, including other people, in the environment. For the most part, this information is communicated via patterns of gaze direction, with gaze shifts signaling changes in the objects of attention. Noting the relevance of gaze cues in social cognition, we speculated that gaze shifts may modulate people's evaluations of others. We investigated this possibility by asking participants to judge the likability (Experiment 1) and physical attractiveness (Experiment 2) of targets displaying gaze shifts indicative of attentional engagement or disengagement with the participants. As expected, person evaluation was moderated by the direction of gaze shifts, but only when the judgment under consideration was relevant to participants. We consider how and when gaze shifts may modulate person perception and its associated behavioral products.     

Human gaze control during real-world scene perception

In human vision, acuity and color sensitivity are best at the point of fixation, and the visual-cognitive system exploits this fact by actively controlling gaze to direct fixation towards important and informative scene regions in real time as needed. How gaze control operates over complex real-world scenes has recently become of central concern in several core cognitive science disciplines including cognitive psychology, visual neuroscience, and machine vision. This article reviews current approaches and empirical findings in human gaze control during real-world scene perception.     

Emotional expression affects the accuracy of gaze perception

Emotional facial expressions are powerful social cues. Here we investigated how emotional expression affects the interpretation of eye gaze direction. Fifty-two observers judged where faces were looking by moving a slider on a measuring bar to the respective position. The faces displayed either an angry, happy, fearful or a neutral expression and were looking either straight at the observer, or were rotated 2°, 4°, 6° or 8° to the left and right. We found that happy faces were interpreted as directed closer to the observer, while fearful and angry faces were interpreted as directed further away. Judgments were most accurate for neutral faces, followed by happy, angry and fearful faces. These findings are discussed on the background of the “self-referential positivity bias”, suggesting that happy faces are preferably interpreted as directed towards the self while negative emotions are interpreted as directed further away.     

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。     

Anxiety meets fear in perception of dynamic expressive gaze

This study investigated in 2 experiments whether reflexive cuing of attention that occurs after perception of a gaze cue is greater for fearful than for happy faces in normal participants, as hypothesized from a social neuroscience perspective. To increase neuroecological validity, dynamic stimulus presentation was used to display faces that simultaneously morphed from a neutral expression into a happy or fearful one and shifted eye gaze from the center to the periphery. Shifts of attention resulting from a natural fearful gaze were expected to be related to participants' anxiety traits, in agreement with the often found increased selective attention to threat in anxious participants. Both hypotheses were confirmed: Fearful faces induced stronger gaze cuing than happy faces, and the strength of this cuing effect was correlated to participants' anxiety levels. These results suggest a neural network, which integrates the processing of gaze, expression, and emotional states to adaptively prime vigilance under threatening circumstances.     

A direct link between gaze perception and social attention

How information is exchanged between the cognitive mechanisms responsible for gaze perception and social attention is unclear. These systems could be independent; the "gaze cueing" effect could emerge from the activation of a general-purpose attentional mechanism that is ignorant of the social nature of the gaze cue. Alternatively, orienting to social gaze direction might be directly determined by the operation of cognitive mechanisms specifically dedicated to gaze perception. This second notion is the dominant assumption in the literature, but there is little direct support for this account. Here, we systematically manipulated observers' perception of gaze direction by implementing a gaze adaptation paradigm. Gaze cueing was reduced only in conditions where perception of specific averted gaze stimuli was impaired (Experiment 1). Adaptation to a pointing stimulus failed to impact gaze cueing (Experiment 2). Overall, these data suggest a direct link between the specific operation of gaze perception mechanisms and the consequential orienting of attention.     

Visual perception and gaze control in judging versus producing phase relations

We studied visual perception and gaze control in nine participants while they judged the relative phase between two oscillating stimuli (Experiment 1), and while they moved their hand--and therewith a concurrent feedback signal--in-phase or in antiphase with an oscillating stimulus (Experiment 2). As in previous studies, the mean relative phase judgements in Experiment 1 corresponded to the presented phase relations (0 degree, 45 degrees, 90 degrees, 135 degrees, and 180 degrees), whereas their standard deviations followed an inverted U-function of relative phase. The relative phase judgements were hardly affected by the degree of visibility (fully visible, inner parts occluded, outer parts occluded) and the amplitude (5 degrees, 10 degrees, and 20 degrees) of the stimuli. Stimulus-gaze coupling decreased as relative phase increased, and its variability correlated with that of the relative phase judgements. Taken together, task performance and gaze behaviour suggested that the judgement of relative phase might be flexibly based on different variables, rather than a single variable like relative direction of motion. In Experiment 2, the production of the antiphase relation was less stable than that of the in-phase relation. Performance deteriorated when the outer parts of the signals were occluded and when their amplitudes were reduced. Stimulus-gaze coupling was stronger during in-phase than during antiphase tracking and weaker when the signals were partially occluded and when their amplitudes were reduced. Stimulus-gaze coupling at 0 degrees and 180 degrees was stronger in Experiment 2 than in Experiment 1, suggesting that the visual perception of relative phase may benefit from its active production. Overall, the results clearly indicated that visual perception of relative phase and the corresponding gaze control are strongly task-dependent.     

Garner interference reveals dependencies between emotional expression and gaze in face perception

The relationship between facial expression and gaze processing was investigated with the Garner selective attention paradigm. In Experiment 1, participants performed expression judgments without interference from gaze, but expression interfered with gaze judgments. Experiment 2 replicated these results across different emotions. In both experiments, expression judgments occurred faster than gaze judgments, suggesting that expression was processed before gaze could interfere. In Experiments 3 and 4, the difficulty of the emotion discrimination was increased in two different ways. In both cases, gaze interfered with emotion judgments and vice versa. Furthermore, increasing the difficulty of the emotion discrimination resulted in gaze and expression interactions. Results indicate that expression and gaze interactions are modulated by discriminability. Whereas expression generally interferes with gaze judgments, gaze direction modulates expression processing only when facial emotion is difficult to discriminate.     

Effects of direct and averted gaze on the perception of facially communicated emotion

Research has largely neglected the effects of gaze direction cues on the perception of facial expressions of emotion. It was hypothesized that when gaze direction matches the underlying behavioral intent (approach-avoidance) communicated by an emotional expression, the perception of that emotion would be enhanced (i.e., shared signal hypothesis). Specifically, the authors expected that (a) direct gaze would enhance the perception of approach-oriented emotions (anger and joy) and (b) averted eye gaze would enhance the perception of avoidance-oriented emotions (fear and sadness). Three studies supported this hypothesis. Study 1 examined emotional trait attributions made to neutral faces. Study 2 examined ratings of ambiguous facial blends of anger and fear. Study 3 examined the influence of gaze on the perception of highly prototypical expressions.     

Scene perception, gaze behavior, and perceptual learning in virtual environments.

More and more immersive environments are developed to provide support for learning or training purposes. Ecological validity of such environments is usually based on learning performance comparisons between virtual environments and their genuine counterparts. Little is known about learning processes occurring in immersive environments. A new technique is proposed for testing perceptual learning during virtual immersion. This methodology relies upon eye-tracking technologies to analyze gaze behavior recorded in relation to virtual objects' features and tasks' requirements. It is proposed that perceptual learning mechanisms engaged could be detected through eye movements. In this study, nine subjects performed perceptual learning tasks in virtual immersion. Results obtained indicated that perceptual learning influences gaze behavior dynamics. More precisely, analysis revealed that fixation number and variability in fixation duration varied with perceptual learning level. Such findings could contribute in shedding light on learning mechanisms as well as providing additional support for validating virtual learning environments.     

I thought you were looking at me: direction-specific aftereffects in gaze perception

Gaze direction is an important social signal in humans and other primates. In this study, we used an adaptation paradigm to investigate the functional organization of gaze perception in humans. Adaptation to consistent leftward or rightward gaze produced a powerful illusion that virtually eliminated observers' perception of gaze in the adapted direction; gaze to that side was seen as pointing straight ahead, though perception of gaze to the opposite side was unimpaired. This striking dissociation held even when retinotopic mapping between adaptation and test stimuli was disrupted by changes in size or head orientation, suggesting that our findings do not reflect adaptation to low-level visual properties. Moreover, adaptation to averted gaze did not affect judgments of line bisection, illustrating that our findings do not reflect a general spatial bias. Our findings provide evidence that humans have distinct populations of neurons that are selectively responsive to particular directions of seen gaze.     

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.     

The gaze of the optimist

Two studies used eye tracking to investigate the attentional preferences of optimists and pessimists to negative emotional stimuli. In both studies, optimistic and pessimistic college students viewed three types of visual stimuli while having their eye movements tracked: skin cancer (melanoma) images, matched schematic line drawings, and neutral faces. In the first study, participants were asked to view the images naturally, whereas in the second study, some participants received a relevance manipulation. Percentage of fixation time to the different images was measured. Optimists showed selective inattention to the skin cancer images, even after controlling for attention to matched schematic line drawings. This relationship remained significant in both studies after controlling for the effects of neuroticism, affect, anxiety, relevance, and perceptual variables. These data suggest that optimists may indeed wear "rose-colored glasses" in their processing of information from the world.     

Eastern observers cannot inhibit their gaze to eye and nose regions in face perception

It has been found that Western observers cannot inhibit their gaze to the eye region, even if they are told to avoid doing so when they observe face stimuli because of the importance of the eye region. However, studies indicate that the nose region is more important for face processing among Eastern observers. We used the “don’t look” paradigm with Eastern observers, in which participants were told to avoid fixating on a specific region (eye, nose, and mouth). The results extend previous findings as both the eye and nose regions attracted their gaze. Interestingly, the fixation behaviors differed for the eyes and nose in terms of the time-dependent view, in which reflexive saccades to the eye with a persistent fixation to the nose were observed. The nose regions could have stronger attractiveness than previously thought.     

Effects of head orientation on gaze perception: How positive congruency effects can be reversed

Several past studies have considered how perceived head orientation may be combined with perceived gaze direction in judging where someone else is attending. In three experiments we tested the impact of different sources of information by examining the role of head orientation in gaze-direction judgements when presenting: (a) the whole face; (b) the face with the nose masked; (c) just the eye region, removing all other head-orientation cues apart from some visible part of the nose; or (d) just the eyes, with all parts of the nose masked and no head orientation cues present other than those within the eyes themselves. We also varied time pressure on gaze direction judgements. The results showed that gaze judgements were not solely driven by the eye region. Gaze perception can also be affected by parts of the head and face, but in a manner that depends on the time constraints for gaze direction judgements. While “positive” congruency effects were found with time pressure (i.e., faster left/right judgements of seen gaze when the seen head deviated towards the same side as that gaze), the opposite applied without time pressure.     

Effects of head orientation on gaze perception: how positive congruency effects can be reversed

Several past studies have considered how perceived head orientation may be combined with perceived gaze direction in judging where someone else is attending. In three experiments we tested the impact of different sources of information by examining the role of head orientation in gaze-direction judgements when presenting: (a) the whole face; (b) the face with the nose masked; (c) just the eye region, removing all other head-orientation cues apart from some visible part of the nose; or (d) just the eyes, with all parts of the nose masked and no head orientation cues present other than those within the eyes themselves. We also varied time pressure on gaze direction judgements. The results showed that gaze judgements were not solely driven by the eye region. Gaze perception can also be affected by parts of the head and face, but in a manner that depends on the time constraints for gaze direction judgements. While “positive” congruency effects were found with time pressure (i.e., faster left/right judgements of seen gaze when the seen head deviated towards the same side as that gaze), the opposite applied without time pressure.