The left visual hemispace bias for the perception of chimeric faces: a further test of the difficulty of discrimination hypothesis

When people make judgments of visual-spatial forms, they generally perform better if the information is presented in their left visual hemispace (LVH), whereas for verbal material, they generally show a right visual hemispace (RVH) bias. For verbal material, the strength and direction of the effect also has been linked to task difficulty, with the bias shifting toward the RVH as task difficulty increases. Two experiments are presented that show the reverse direction of change for a nonverbal task; that is, when a nonverbal task is more difficult, the usual LVH effect shifts toward an RVH bias. Taking into account recent developments in theory and research on hemispheric differences in styles of information processing, we propose that task difficulty is related more generally to changes in processing style.     

A left hemisphere, but not right hemispace, advantage for tactual simultaneity judgments

Hemispheric asymmetries for tactile simultaneity judgments were investigated in 34 dextral adults. Pairs of vibrotactile stimuli with simultaneous or successive onsets were delivered unilaterally to the left or right hand. Participants made a forced-choice, bipedal response, indicating whether a stimulus was simultaneous or successive. The effect of hemispatial attentional biases was investigated, using ipsilateral (arms uncrossed) and contralateral (arms crossed) hand placements. Trials presented to the right hand were associated with fewer errors and a trend for faster response times than were those presented to the left hand. There was no asymmetry in response bias. Manipulations of hemispace did not affect the right hand advantage. These results confirm the existence of a left hemisphere temporal-processing advantage but fail to demonstrate that the asymmetry is the result of a rightward attentional bias. The implications of these results for absolute and relative models of hemispheric specialization are discussed.     

Development of upper visual field bias for faces in infants

The spatial location of the face and body seen in daily life influences human perception and recognition. This contextual effect of spatial locations suggests that daily experience affects how humans visually process the face and body. However, it remains unclear whether this effect is caused by experience, or innate neural pathways. To address this issue, we examined the development of visual field asymmetry for face processing, in which faces in the upper visual field were processed preferentially compared to the lower visual field. We found that a developmental change occurred between 6 and 7 months. Older infants aged 7–8 months showed bias toward faces in the upper visual field, similar to adults, but younger infants of 5–6 months showed no such visual field bias. Furthermore, older infants preferentially memorized faces in the upper visual field, rather than in the lower visual field. These results suggest that visual field asymmetry is acquired through development, and might be caused by the learning of spatial location in daily experience.     

Flexible target templates improve visual search accuracy for faces depicting emotion

Theories of visual attention hypothesize that target selection depends upon matching visual inputs to a memory representation of the target – i.e., the target or attentional template. Most theories assume that the template contains a veridical copy of target features, but recent studies suggest that target representations may shift "off veridical" from actual target features to increase target-to-distractor distinctiveness. However, these studies have been limited to simple visual features (e.g., orientation, color), which leaves open the question of whether similar principles apply to complex stimuli, such as a face depicting an emotion, the perception of which is known to be shaped by conceptual knowledge. In three studies, we find confirmatory evidence for the hypothesis that attention modulates the representation of an emotional face to increase target-to-distractor distinctiveness. This occurs over-and-above strong pre-existing conceptual and perceptual biases in the representation of individual faces. The results are consistent with the view that visual search accuracy is determined by the representational distance between the target template in memory and distractor information in the environment, not the veridical target and distractor features.

     

Task framing reduces emotion decoding negativity biases in social anxiety

Social anxiety is associated with difficulty in decoding emotional expressions. In this work, we present two experiments demonstrating that manipulating the apparent social relevance of an emotion‐identification task can reduce these difficulties. In Experiment 1, we find that social anxiety predicts an oversensitivity to anger expressions when participants are told they are completing a task that measures social skills. However, when the same task is framed as a measure of intellectual skills, this oversensitivity to anger is eliminated. Experiment 2 finds that social anxiety interferes with participants' ability to discriminate real from fake smiles when participants are told they are completing a test of social skills, but not when they are completing an ostensible measure of intellectual skills.     

Irrelevant visual faces influence haptic identification of facial expressions of emotion

This study demonstrates that when people attempt to identify a facial expression of emotion (FEE) by haptically exploring a 3D facemask, they are affected by viewing a simultaneous, task-irrelevant visual FEE portrayed by another person. In comparison to a control condition, where visual noise was presented, the visual FEE facilitated haptic identification when congruent (visual and haptic FEEs same category). When the visual and haptic FEEs were incongruent, haptic identification was impaired, and error responses shifted toward the visually depicted emotion. In contrast, visual emotion labels that matched or mismatched the haptic FEE category produced no such effects. The findings indicate that vision and touch interact in FEE recognition at a level where featural invariants of the emotional category (cf. precise facial geometry or general concepts) are processed, even when the visual and haptic FEEs are not attributable to a common source. Processing mechanisms behind these effects are considered.     

Differences in judgments of learning difficulty

Academically successful and less successful fifth graders were asked to make judgments about the ease of understanding and remembering various sentences and were given the opportunity to attempt to remember some of them before being asked to judge new sets of sentences. The results of the first experiment indicate that, at the beginning of the experiment, the successful students were much more likely than their less successful peers to realize that sentences expressing arbitrary relationships were more difficult to remember. These differences became even greater after students were given the opportunity to attempt to remember some of the sentences they had judged initially. The memory performance of the successful students also improved as they became more familiar with the experimental task, but the performance of the less successful students did not. The results of the second experiment showed that less successful students who had received appropriate training were able to use information about the arbitrariness of relationships as the basis for their judgments of learning difficulty. The training also facilitated their ability to remember. Implications of these findings are discussed.     

任务难度对自闭症儿童视觉搜索优势显现的影响

探究自闭症谱系障碍(ASD)儿童视觉搜索优势的显现是否受任务难度影响及优势存在机理。本研究采集ASD和正常发育(TD)儿童完成不同难度等级视觉搜索任务的行为和眼动数据。结果发现：在高难度等级任务中ASD组的准确率显著高于TD组;ASD组在任务中对目标刺激的回视次数、对靶子和外周感兴趣区的注视时间显著少于TD组,且ASD组偏好注视刺激的右侧区域。结果表明ASD儿童视觉搜索优势显现受任务难度影响,且可能与其对干扰刺激增强的知觉能力有关。     

A basis for bias in geographical judgments

To determine why North Americans tend to locate European cities south of North American cities at similar latitudes (Tversky, 1981), we had observers provide bearing estimates between cities in the U.S. and Europe. Earlier research using latitude estimates of these cities has indicated that each continent has several subjective regions (Friedman & Brown, 2000a). Participants judged cities from two subjectively northern regions (Milwaukee-Munich), two subjectively southern regions (Memphis-Lisbon), and the two "crossed" regions (Albuquerque-Geneva; Minneapolis-Rome). Estimates were biased only when cities from the subjectively northern regions of North America were paired with cities from the subjectively southern region of Europe. In contrast to the view that biases are derived from distorted or aligned map-like representations, the data provide evidence that the subjective representation of global geography is principally categorical. Biases in numerical location estimates of individual cities and in bearing estimates between city pairs are derived from plausible reasoning processes operating on the same categorical representations.     

Ratings of emotion in faces are influenced by the visual field to which stimuli are presented

This experiment was designed to assess the differential impact of initially presenting affective information to the left versus right hemisphere on both the perception of and response to the input. Nineteen right-handed subjects were presented with faces expressing happiness and sadness. Each face was presented twice to each visual field for an 8-sec duration. The electro-oculogram (EOG) was monitored and fed back to subjects to train them to keep their eyes focused on the central fixation point as well as to eliminate trials confounded by eye movement artifact. Following each slide presentation, subjects rated the intensity of the emotional expression depicted in the face and their emotional reaction to the face on a series of 7-point rating scales. Subjects reported perceiving more happiness in response to stimuli initially presented to the left hemisphere (right visual field) compared to presentations of the identical faces to the right hemisphere (left visual field). This effect was predominantly a function of ratings on sad faces. A similar, albeit less robust, effect was found on self-ratings of happiness (the degree to which the face elicited the emotion in the viewer). These data challenge the view that the right hemisphere is uniquely involved in all emotional behavior. The implications of these findings for theories concerning the lateralization of emotional behavior are discussed.     

Perceptual asymmetry for chimeric faces across the life span

Perceptual asymmetries for processing chimeric faces were investigated in dextral subjects, ranging in age from 5 years to elderly adults. The task involved deciding which member of a pair of face chimeras presented in free vision looks happier, the one with the smile to the left or its mirror image with the smile to the right (Levy, Heller, Banich, & Burton, 1983a, Brain and Cognition, 2, 404-419). A leftward bias was found for all age groups. However, kindergarteners' mean asymmetry score was lower than that of all other groups combined, most likely due to noise in their data. The direction in which subjects drew circles with their left and right hands was also observed as an index of interhemispheric communication. All groups showed a bias toward drawing the circles in concordant directions except the kindergarteners. The relation between subjects' performance on the circle drawing and facebook tasks is discussed.     

Age-related differences in attentional bias for emotional faces

Past research suggests an aging-related positivity effect in orienting to faces. However, these studies have eschewed direct comparison of orienting when positive and negative faces are presented simultaneously, thereby potentially underestimating the degree to which emotional valence influences such effects. In the current study younger and older adults viewed face pairs for 1000 ms, and upon face-pair offset indicated the location of a dot that appeared in the former location of one of the faces, to assess attentional orienting. When shown negative–neutral pairs, both age groups were biased to attend to negative faces, but when shown positive–negative pairs only younger adults showed a bias toward negative; older adults showed a lack of orienting toward either emotional face. Results suggest younger adults have a negativity bias in attention orienting regardless of the valence of nearby stimuli, whereas older adults show an absence of this bias when positive information is present.     

Attentional bias for words and faces in social anxiety

Conflicting findings concerning the nature and presence of attentional bias in social anxiety and social phobia have been reported in the literature. This paper reports the findings of two studies comparing people with high and low social anxiety on dot probe tasks using words, faces photographed in front view, and faces photographed in profile as stimuli. In Study 1 those with high social anxiety displayed an attentional bias towards negative faces. The low social anxiety group showed an attentional bias towards positive faces. No significant effects were observed on the dot probe using words as stimuli. Study 2 used pairs of faces presented in profile as though looking at each other. One of the faces displayed either a positive, negative or neutral expression. The second face always had a neutral expression, and in half of the trials it was the subject's own face. The findings of this more ecologically valid procedure replicated those of Study 1. Facilitated attention to dots following emotional faces was specific to threatening facial stimuli. From these studies it appears that the facial dot probe task is a more sensitive index of attentional bias than the word task in a non-clinical sample with social anxiety.     

Evaluating the independence of sex and expression in judgments of faces

Face recognition models suggest independent processing for functionally different types of information, such as identity, expression, sex, and facial speech. Interference between sex and expression information was tested using both a rating study and Garner's selective attention paradigm using speeded sex and expression decisions. When participants were asked to assess the masculinity of male and female angry and surprised faces, they found surprised faces to be more feminine than angry ones (Experiment 1). However, in a speeded-classification situation in the laboratory in which the sex decision was either "easy" relative to the expression decision (Experiment 2) or of more equivalent difficulty (Experiment 3), it was possible for participants to attend selectively to either dimension without interference from the other. Qualified support is offered for independent processing routes.     

Interpersonal relationships moderate the effect of faces on person judgments

Previous research suggests that people form impressions of others based on their facial appearance in a very fast and automatic manner, and this especially holds for trustworthiness. However, as yet, this process has been investigated mostly in a social vacuum without taking interpersonal factors into account. In the current research, we demonstrate that both the relationship context that is salient at the moment of an interaction and the performed behavior are important moderators of the impact of facial cues on impression formation. It is shown that, when the behavior of a person we encounter is ambiguous in terms of trustworthiness, the relationship most salient at that moment is of crucial impact on whether and how we incorporate facial cues communicating (un)trustworthiness in our final evaluations. Ironically, this can result in less positive evaluations of interaction partners with a trustworthy face compared to interaction partners with an untrustworthy face. Implications for research on facial characteristics, trust, and relationship theories are discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

Asymmetry of perception in free viewing of chimeric faces

We have devised a new free-vision task to index functional cerebral asymmetry for processing facial characteristics. Confirming its sensitivity to properties of lateralized hemispheric functions, left- and right-handers were clearly differentiated on this task with respect to several aspects of performance that conform with known differences between handedness groups in hemispheric asymmetry. Additionally, there were highly reliable and stable individual differences in perceptual asymmetries within handedness. Analyses of items in the task revealed that most of the differences between items in the asymmetries they elicited were random.     

An own-age bias in age estimation of faces

IntroductionAge estimation performances may be influenced by group biases.ObjectiveThis study investigated whether we are more accurate at estimating the age of people from one's own-age than the age of younger or older people.MethodChildren, young and older adults’ performances at estimating both in-group and out-group faces were compared.ResultsA significant “Age of participants” × “Age of face stimuli” interaction was revealed. Moreover, the age of children's faces was more accurately estimated than the age of young and older adults’ faces by the three groups of participants.ConclusionThe present results revealed the occurrence of an own-age bias for children, young and older adults in age estimation. Several explanations to this own-age effect are discussed.     

Response bias and judgments of the location of clicks in sentences

This study examines the view that response bias is the basis of the “click effect,” i.e., the influence of grammatical structure on subjects’ location of clicks sounded during the presentation of a sentence. It is argued that, since response bias is more likely to operate when one is unsure of one’s perception, if response bias generates the “click effect,” the effect should be weaker for certain than for uncertain responses. Subjects were asked to identify the location of the click and allowed to make more than one response if they were uncertain of their first choice. Using the number of locations selected as an index of uncertainty, it was found that when a subject was less certain, the click was less likely to be judged as having occurred in the major grammatical break. Further, performance was superior when the click had been in the break, and this effect, which was more pronounced for “certain” responses, was not eliminated by correcting for possible response bias. It is concluded that the "click effect" is not attributable solely to response bias.