Effect of stimulus opening size in global dominance with orientation classification task

The aims of this study is to examine whether global dominance depends on the opening size of the stimulus with concentric hierarchical figures and orientation classification task and to determine the role of the salience of global opening and its coincidence with vertical symmetry axis of context. In the first experiment, participants had to indicate the opening direction of stimuli, which were open-left and open-right figures. Three openings were included: 10, 25 and 50% of the total circle perimeter. The results showed a local advantage with stimuli of 10%, absence of global or local advantage with stimuli of 25% and global advantage with stimuli of 50%. In the second experiment, stimuli with an opening of 50% were presented randomly in several positions in the visual field in order to avoid the coincidence of global opening with the vertical symmetry axis of context. The results showed an absence of global or local advantage. These findings indicate that global dominance with orientation classification task depends on stimulus characteristics such as opening size, and strategies used in visual recognition.     

Selective attention to global and local information: Effects of visual angle,exposure duration,and eccentricity on processing dominance

Abstract

The size and exposure duration of stimuli have been found to be relevant factors to the issue of processing dominance. Nevertheless, the relation between these two factors and their possible effects on processing dominance have never been studied. The aim of the present research was twofold: (a) to examine whether size and the exposure duration of stimuli affect processing dominance; (b) to examine whether these effects depend on the same/different eccentricity of global and local levels. Stimuli were presented at three exposure durations: 140 msec, 70 msec, and 40 msec. The overall sizes of stimuli were varied at three levels: small (3[ddot]), intermediate (6[ddot]) and large (12[ddot]). In Experiment 1 stimuli were used whose global and local levels were at different eccentricity (Hs and Ss stimuli). In Experiment 2 stimuli whose global and local levels were at the same eccentricity (Cs stimuli) were used. The results showed that the effects of visual angle on processing dominance are independent of the exposure duration of stimuli used. The transition from global to local dominance as visual angle is increased depends on the eccentricity of global and local information: It only appears when the eccentricity is different and biased towards the local level (Hs and Ss stimuli). Finally, the size of the effect is modulated by the visual angle subtended by the stimuli: the size of the effect of global advantage was inversely related to visual angle. The size of the interference effect from the local level to the global level was directly related to the visual angle, whereas that from the global level to the local level was inversely related to the visual angle subtended by the stimuli.     

Dimensional dominance and stimulus discriminability.

The relationship between the discriminability of scaling stimuli and assessed dimensional dominance was investigated in three studies. Sixty kindergarten children were assessed using a psychophysical scaling method to determine JND values for the size, brightness, and orientation dimensions. Thirty of the same subjects were then assessed for dimensional dominance using stimuli of two levels of known discriminability, based on the obtained JND values. In a third experiment, the remaining 30 subjects were assessed for dimensional dominance using stimuli that systematically emphasized the values of one dimension relative to the other two dimensions, again based on obtained JND values.The results indicated that (1) kindergarten children were able to perform consistently during psychophysical scaling, and there was little variability between children in their judgments of stimuli, (2) the overall level of discriminability affects dimensional dominance scaling behavior, with subjects more likely to exhibit dominance for one dimension when all the values of scaling stimuli are high in discriminability, and (3) some support for the hypothesis that dimensional dominance scaling behavior can be manipulated by manipulating the relative discriminability of scaling stimuli was found, though the trend was not clear.The relative discriminability of scaling stimuli appears to have some effects on dimensional dominance scaling behavior of young children. However, some pre-experimental bias to attend to a particular dimension seems to remain even when the values of all dimensions present are of equal and known discriminability. Dimensional dominance is a function of an interaction between discriminability of scaling stimuli and the experiential bias or perceptual set of the subject.     

The distortion of spatial relationships between local elements in hierarchical patterns decreases the global advantage effect

The present study examined the influence of perceptual organization on the processing of global and local information in hierarchical patterns. In two experiments, we examined whether disturbing the spatial relationships between local elements by introducing between-element distance and size heterogeneity affected global processing dominance. The effects on global processing dominance of undistorted compound stimuli with equidistant and homogeneous local elements were compared with those of compound stimuli which presented between-element distance heterogeneity (Experiment 1) or heterogeneity in size (Experiment 2). The results showed that the global advantage effect decreased similarly under conditions of between-element distance and size heterogeneity that disturbed the spatial relationships between local elements. The results provide new evidence on the role of perceptual organization in hierarchical patterns processing.     

Effects of exposure duration and eccentricity of global and local information on processing dominance

Abstract

The effects of exposure duration of stimuli and the eccentricity of local and global information in hierarchical patterns on processing dominance were examined using a paradigm of selective attention and masked stimuli. In the first experiment, the aim was to determine whether the exposure duration of stimuli has differential effects on processing dominance. Stimuli were presented with spatial certainty and controlled eccentricity at four exposure durations (unlimited, 140 msec, 70 msec and 40 msec). The results showed global advantage independently of the exposure duration used. Differential effects were obtained in relation to the interference between the global and local levels depending on the exposure duration. The purpose of the second and third experiments was to determine whether the eccentricity of local and global levels affects processing dominance under a condition of brief exposure duration of stimuli. The results of Experiment 2 showed local dominance when the eccentricity was different for both levels and biased to the local level (H's and S's stimuli). On the contrary, they showed global dominance when the eccentricity of the two levels was the same (C's stimuli). The results of Experiment 3 revealed that the effect of global dominance persisted when the stimuli presented local and global information foveally.     

Global and local processing in nonattended objects: a failure to induce local processing dominance.

Paquet and Merikle (1988) found that subjects can ignore the category of unattended local forms but not that of global forms. Does this finding reflect a priority for global information during perception? In 5 studies, 2 compound stimuli, each surrounded by a frame, were presented side by side, and attention was directed to 1 of the stimuli. The first 2 studies examined whether local dominance would emerge if a small gap (Experiment 1) or the presence of small white lines (Experiment 2) on the surrounding frame specified the target object. No evidence for local dominance was found. Three additional studies examined whether local dominance would be obtained if subjects had extensive practice identifying the local aspect of stimulus displays. Although local practice led to automatic detection of unattended local targets, it did not affect the processing of the global aspect. These results are proposed to exemplify the priority of global information during perception.     

The effects of precedence on Navon-induced processing bias in face recognition

Macrae and Lewis (2002) showed that repeated reporting of the global dimension of Navon stimuli improved performance in a subsequent face identification task, whilst reporting the features of the Navon stimuli impaired performance. Using a face composite task, which is assumed to require featural processing, Weston and Perfect (2005) showed the complementary pattern: Featural responding to Navon letters speeded performance. However, both studies used Navon stimuli with global precedence, in which the overall configuration is easier to report than the features. Here we replicate the two studies above, whilst manipulating the precedence (global or featural) of the letter stimuli in the orientation task. Both studies replicated the previously reported findings with global precedence stimuli, but showed the reverse pattern with local precedence stimuli. These data raise important questions as to what is transferred between the Navon orientation task and the face-processing tasks that follow.     

视听刺激突显性对视觉主导效应的影响

本研究使用空间任务-转换范式,控制视、听刺激的突显性,探讨自下而上注意对视觉主导效应的影响。结果表明视、听刺激突显性显著地影响视觉主导效应,实验一中当听觉刺激为高突显性时,视觉主导效应显著减弱。实验二中当听觉刺激为高突显性并且视觉刺激为低突显性时,视觉主导效应进一步减弱但依然存在。结果支持偏向竞争理论,在跨通道视听交互过程中视觉刺激更具突显性,在多感觉整合过程中更具加工优势。     

Global/local processing of hierarchical visual stimuli in a conflict–choice task by capuchin monkeys (<Emphasis Type="Italic">Sapajus</Emphasis> spp.)

In the last two decades, comparative research has addressed the issue of how the global and local levels of structure of visual stimuli are processed by different species, using Navon-type hierarchical figures, i.e. smaller local elements that form larger global configurations. Determining whether or not the variety of procedures adopted to test different species with hierarchical figures are equivalent is of crucial importance to ensure comparability of results. Among non-human species, global/local processing has been extensively studied in tufted capuchin monkeys using matching-to-sample tasks with hierarchical patterns. Local dominance has emerged consistently in these New World primates. In the present study, we assessed capuchins’ processing of hierarchical stimuli with a method frequently adopted in studies of global/local processing in non-primate species: the conflict–choice task. Different from the matching-to-sample procedure, this task involved processing local and global information retained in long-term memory. Capuchins were trained to discriminate between consistent hierarchical stimuli (similar global and local shape) and then tested with inconsistent hierarchical stimuli (different global and local shapes). We found that capuchins preferred the hierarchical stimuli featuring the correct local elements rather than those with the correct global configuration. This finding confirms that capuchins’ local dominance, typically observed using matching-to-sample procedures, is also expressed as a local preference in the conflict–choice task. Our study adds to the growing body of comparative studies on visual grouping functions by demonstrating that the methods most frequently used in the literature on global/local processing produce analogous results irrespective of extent of the involvement of memory processes.     

Revisiting the global-dominance phenomenon outside the focus of attention

Previous research has demonstrated global dominance for attended and unattended stimuli. In this paper, this phenomenon is shown to be restricted to small compound stimuli. As a first step, local dominance was obtained with large (8 deg in height) attended stimuli when a single stimulus was displayed. Next, dominance in attended and unattended stimuli was investigated by displaying two large compound stimuli, one surrounded by a square (attended compound stimulus), the other one enclosed in a circle (unattended compound stimulus). The way attention was directed to the attended stimulus was varied. No dominance was observed when subjects were instructed to process the stimulus appearing in the square (experiment 2). However, when a rapid-onset cue pre-directed attention to the attended stimulus, local dominance emerged for attended, but not for unattended stimuli (experiment 3). This latter result was obtained whether or not subjects were more experienced at local than global processing (experiment 4). The implications of the results for the locus of processing dominance are discussed.     

Subliminal Gestalt grouping: Evidence of perceptual grouping by proximity and similarity in absence of conscious perception

Previous studies making use of indirect processing measures have shown that perceptual grouping can occur outside the focus of attention. However, no previous study has examined the possibility of subliminal processing of perceptual grouping. The present work steps forward in the study of perceptual organization, reporting direct evidence of subliminal processing of Gestalt patterns. In two masked priming experiments, Gestalt patterns grouped by proximity or similarity that induced either a horizontal or vertical global orientation of the stimuli were presented as masked primes and followed by visible targets that could be congruent or incongruent with the orientation of the primes. The results showed a reliable priming effect in the complete absence of prime awareness for both proximity and similarity grouping principles. These findings suggest that a phenomenal report of the Gestalt pattern is not mandatory to observe an effect on the response based on the global properties of Gestalt stimuli.     

The effects of local and global processing orientation on eyewitness identification performance

Recent work has demonstrated that performance on a simultaneous target-present photographic line-up can be enhanced by prior global processing orientation, and hindered by prior local processing orientation induced by processing Navon letter stimuli. A series of studies explore the generality of this processing bias effect using either videotaped scenarios or live interactions. Five experiments demonstrate that these effects are seen across a range of test stimuli, test formats, and test instructions.These data inform the processes engaged in by witnesses when making line-up identifications and indicate that it may be possible to improve the accuracy of witnesses making such judgements.     

The effects of local and global processing orientation on eyewitness identification performance

Recent work has demonstrated that performance on a simultaneous target-present photographic line-up can be enhanced by prior global processing orientation, and hindered by prior local processing orientation induced by processing Navon letter stimuli. A series of studies explore the generality of this processing bias effect using either videotaped scenarios or live interactions. Five experiments demonstrate that these effects are seen across a range of test stimuli, test formats, and test instructions. These data inform the processes engaged in by witnesses when making line-up identifications and indicate that it may be possible to improve the accuracy of witnesses making such judgements.     

字形判断过程中的整体与局部优先效应:来自反应时和眼动指标的证据

本文采用4(字形)x2(字号)的组内设计,对各条件的反应时、首次注视和总注视时间进行分析,从而探讨汉字识别整体或局部优先的问题。无论字号大小,部件位置错误条件的反应时均显著短于部件内容错误。小号字在部件位置和内容错误条件的首次注视时间差异不显著。大号字在部件位置错误条件的首次注视时间显著长于部件内容错误。部件位置错误条件总注视时间均显著短于部件内容错误。以上结果暗示了汉字识别中整体和局部加工存在不同的时间进程。     

Attention allocation modulates the processing of hierarchical visual patterns: a comparative analysis of capuchin monkeys (Cebus apella) and humans

Humans show a global advantage when processing hierarchical visual patterns, and they detect the global level of stimulus structure more accurately and faster than the local level in several stimulus contexts. By contrast, capuchins (Cebus apella) and other monkey species show a strong local advantage. A key factor which, if manipulated, could cause an inversion of this effect in monkeys is still to be found. In this study, we examined whether it was possible to induce attention allocation to global and local levels of perceptual analysis in capuchin monkeys and if by doing so, their local dominance could be reversed. We manipulated attentional bias using a matching-to-sample (MTS) task where the proportion of trials requiring global and local processing varied between conditions. The monkeys were compared with humans tested with the same paradigm. Monkeys showed a local advantage in the local bias condition but a global advantage in the global bias condition. The role of attention in processing was confined to the local trials in a first phase of testing but extended to both local and global trials in the course of task practice. Humans exhibited an overall global dominance and an effect of attentional bias on the speed of processing of the global and local level of the stimuli. These results indicate a role for attention in the processing of hierarchical stimuli in monkeys and are discussed in relation to the extent to which they can explain the differences between capuchin monkeys and humans observed in this and other studies.     

金融危机背景下家庭社会地位对大三学生择业动机的影响：社会支配倾向的中介作用

以504名来自5所高校三年级大学本科生为被试,采用问卷法收集数据,探讨了家庭社会地位对大学生择业动机的影响。结果表明：（1）家庭社会地位对大学生内部择业动机具有显著的预测作用,家庭社会地位越高,内部择业动机越强;（2）社会支配倾向对家庭社会地位与内部择业动机之间的关系起中介作用,家庭社会地位通过社会支配倾向对内部择业动机产生间接影响;（3）未发现家庭社会地位、社会支配倾向与外部择业动机之间的显著相关。     

Perceptual sensitivity to dimensional and similarity relations in free and rule-governed classifications

Two experiments were conducted to investigate the perceptual primacy of dimensional and similarity relations in the stimulus classifications of younger and older subjects. In Experiment 1, 4- and 10-year-olds were given free classifications in which they could group stimuli according to overall similarity or identities in size, color, or orientation. Both age groups classified stimuli most frequently according to identities on separate dimensions. In Experiment 2, 4-year-olds and adults were given free classifications followed by rule-governed classifications which required them to group stimuli according to specific relations. In the free classifications, a majority of subjects in both age groups classified the stimuli most frequently according to identities on separate dimensions. In the rule-governed classifications, both age groups were more accurate when a single separate relation was required for solution than when overall similarity was required. These results support a differential-sensitivity view of perceptual development, which asserts that individuals at all ages primarily perceive and use separate relations.     

A cluster-based approach to selecting representative stimuli from the International Affective Picture System (IAPS) database

The International Affective Picture System (IAPS; Lang, Bradley, & Cuthbert, 2008) is a stimulus database that is frequently used to investigate various aspects of emotional processing. Despite its extensive use, selecting IAPS stimuli for a research project is not usually done according to an established strategy, but rather is tailored to individual studies. Here we propose a standard, replicable method for stimulus selection based on cluster analysis, which re-creates the group structure that is most likely to have produced the valence arousal, and dominance norms associated with the IAPS images. Our method includes screening the database for outliers, identifying a suitable clustering solution, and then extracting the desired number of stimuli on the basis of their level of certainty of belonging to the cluster they were assigned to. Our method preserves statistical power in studies by maximizing the likelihood that the stimuli belong to the cluster structure fitted to them, and by filtering stimuli according to their certainty of cluster membership. In addition, although our cluster-based method is illustrated using the IAPS, it can be extended to other stimulus databases.     

Binocular rivalry: a window into emotional processing in aging

Previous binocular rivalry studies with younger adults have shown that emotional stimuli dominate perception over neutral stimuli. Here we investigated the effects of age on patterns of emotional dominance during binocular rivalry. Participants performed a face/house rivalry task where the emotion of the face (happy, angry, neutral) and orientation (upright, inverted) of the face and house stimuli were varied systematically. Age differences were found with younger adults showing a general emotionality effect (happy and angry faces were more dominant than neutral faces) and older adults showing inhibition of anger (neutral faces were more dominant than angry faces) and positivity effects (happy faces were more dominant than both angry and neutral faces). Age differences in dominance patterns were reflected by slower rivalry rates for both happy and angry compared to neutral face/house pairs in younger adults, and slower rivalry rates for happy compared to both angry and neutral face/house pairs in older adults. Importantly, these patterns of emotional dominance and slower rivalry rates for emotional-face/house pairs disappeared when the stimuli were inverted. This suggests that emotional valence, and not low-level image features, were responsible for the emotional bias in both age groups. Given that binocular rivalry has a limited role for voluntary control, the findings imply that anger suppression and positivity effects in older adults may extend to more automatic tasks.     

The depth and selectivity of suppression in binocular rivalry

Binocular rivalry occurs when the two eyes are presented with incompatible stimuli and the perceived image alternates between the two stimuli. The aim of this study was to find out whether the periodic perceptual loss of a monocular stimulus during binocular rivalry is mirrored by a comparable loss of contrast sensitivity. We presented brief test stimuli to one eye while its conditioning stimulus was dominant or suppressed. The test stimuli were varied widely across four stimulus domains--namely, the relative stimulation of medium- and long-wavelength-sensitive cones, duration, spatial frequency, and grating orientation. The result in each case was the same. Suppression depended slightly or not at all on the type of test stimulus, and contrast sensitivity during suppression was around 64% of that during dominance. The effect of suppression on sensitivity is therefore very weak, relative to its effect on the perceived image. Furthermore, suppression was largely independent of the similarity between the conditioning and the test stimuli, indicating that our results are better explained by eye suppression than by stimulus suppression. A model is presented to account for the small, monocular sensitivity loss during suppression: It assumes that test detection precedes conditioning stimulus perception in the visual pathway.