Processing global information in briefly presented pictures

Summary The effect on object recognition of the processing of the global information in contextually coherent scenes was investigated in two experiments. In Experiment 1 subjects saw 100 ms presentations of line drawings containing objects that were either usual or unusual given the picture context. Following each exposure they were required to select from among four objects the one that had been contained in the scene. The consistency of the three distractor alternatives with the meaning of the picture was varied. Recognition accuracy was poor for unusual objects and when the distractors were consistent with the picture meaning and did not substantially differ from the performance of subjects who selected response alternatives after being provided with a theme of the picture, without actually viewing the pictures. This supports the conclusion that subjects were responding on the basis of the global information but not the local object information in the pictures. When the exposure duration was increased to 2 s (Experiment 2), processing of local information was apparent for both usual and unusual objects but effects of the global information were still evident.     

Scene consistency in object and background perception

Does knowledge about which objects and settings tend to co-occur affect how people interpret an image? The effects of consistency on perception were investigated using manipulated photographs containing a foreground object that was either semantically consistent or inconsistent with its setting. In four experiments, participants reported the foreground object, the setting, or both after seeing each picture for 80 ms followed by a mask. In Experiment 1, objects were identified more accurately in a consistent than an inconsistent setting. In Experiment 2, backgrounds were identified more accurately when they contained a consistent rather than an inconsistent foreground object. In Experiment 3, objects were presented without backgrounds and backgrounds without objects; comparison with the other experiments indicated that objects were identified better in isolation than when presented with a background, but there was no difference in accuracy for backgrounds whether they appeared with a foreground object or not. Finally, in Experiment 4, consistency effects remained when both objects and backgrounds were reported. Semantic consistency information is available when a scene is glimpsed briefly and affects both object and background perception. Objects and their settings are processed interactively and not in isolation.     

Change detection in complex scenes: hemispheric contribution and the role of perceptual and semantic factors

The perceptual salience and semantic relevance of objects for the meaning of a scene were evaluated with multiple criteria and then manipulated in a change-detection experiment that used an original combination of one-shot and tachistoscopic divided-visual-field paradigms to study behavioural hemispheric asymmetry. Coloured drawings that depicted meaningful situations were presented centrally and very briefly (120 ms) and only the changes were lateralised by adding an object in the right or in the left visual hemifield. High salience and high relevance improved both response times (RTs) and accuracy, although the overall contribution of salience was greater than that of relevance. Moreover, only for low-salience changes did relevance affect speed. RTs were shorter when a change occurred in the left visual hemifield, suggesting a right-hemisphere advantage for detection of visual change. Also, men responded faster than women. The theoretical and methodological implications are discussed.     

Object identification: The mental representation of physical and conceptual attributes

In two experiments, subjects indicated whether two pictures of familiar objects were equivalent. The picture pairs were identical, showed the same object in various perspectives and states, or showed different objects with varying degrees of conceptual relatedness. In Experiment 1, the equivalence criterion for judging the picture pairs was varied between subjects (identity of pictures; conceptual equivalence of objects at subordinate, basic, or superordinate level). The reaction times of the four subject groups suggest that a pictorial stimulus is not always mentally represented in the same way, and that the instructions given determine which attributes of the stimulus are represented. In Experiment 2, the visual similarity of the picture pairs was varied. The results indicate, at least with a basic-level equivalence instruction, that not only perceptual, but also non-perceptual, functional attributes are represented—namely, those that, according to Rosch et al. (1976), are common to the members of a superordinate category.     

Semantic consistency versus perceptual salience in visual scenes: Findings from change detection

In a one-shot change detection task, we investigated the relationship between semantic properties (high consistency, i.e., diagnosticity, versus inconsistency with regard to gist) and perceptual properties (high versus low salience) of objects in guiding attention in visual scenes and in constructing scene representations. To produce the change an object was added or deleted in either the right or left half of coloured drawings of daily-life events. Diagnostic object deletions were more accurately detected than inconsistent ones, indicating rapid inclusion into early scene representation for the most predictable objects. Detection was faster and more accurate for high salience than for low salience changes. An advantage was found for diagnostic object changes in the high salience condition, although it was limited to additions when considering response speed. For inconsistent objects of high salience, deletions were detected faster than additions. These findings may indicate that objects are primarily selected on a perceptual basis with subsequent and supplementary effect of semantic consistency, in the sense of facilitation due to object diagnosticity or lengthening of processing time due to inconsistency.     

PIGEONS ARE SENSITIVE TO THE SPATIAL ORGANIZATION OF COMPLEX VISUAL STIMULI

Abstract— Two experiments investigated the role of spatial organisation in the discrimination and generalization of complex visual stimuli by pigeons. In Experiment 1, after pigeons had been trained to discriminate line drawings of four objects, they were tested with novel pictures in which the same component parts of the objects were spatially rearranged. The spatially scrambled pictures led to a dramatic drop in recognition accuracy, hut responding remained above chance. In Experiment 2, pigeons reached a high level of discriminative performance when required to choose among four different spatial arrangements of the same object parts. These results confirm Cerella's (1980) conclusion that pigeons discriminate the component parts of complex visual stimuli, but. unless it is assumed that the scrambling deleted or created emergent features, the results disconfirm his conclusion that spatial organization plays no role in pigeons' picture perception.     

How children view pictures: Children's responses to pictures as things in themselves and as representations of something else

In four experiments we examined under what conditions children around 4 years of age could overcome their normal tendency to treat a picture as transparent and attend to it also as a thing in itself. In Experiment 1, many children chose a picture of food as something “you can really eat” even after having identified it as “just a picture.” In Experiment 2, however, children were able to respond appropriately to implicit requests for a picture as distinct from a real exemplar of the thing represented when the context indicated the correct response. In these tasks, children could succeed by treating picture status simply as an attribute. In Experiments 3 and 4, children were asked to comment on the appearance and reality of pictures, deceptive (trick) objects and real things. Significantly poorer performance on pictures and tricks than on real things suggested that some children have difficulty holding two interpretations of the same input; that is, understanding that a picture has two identities.     

Effect of name agreement on prefrontal activity during overt and covert picture naming

In recent neuroimaging studies, various tasks have been used to examine prefrontal cortex involvement in semantic retrieval and selection. One such task, picture naming, has yielded inconsistent results across studies. One potential explanation for this inconsistency is that the magnitude of prefrontal activity during picture naming depends on the extent to which a given picture evokes a single reliable meaning. To test this hypothesis, fMRI activity in the prefrontal cortex was measured while subjects named pictures with either high or low name agreement. In Experiment 1, subjects named black-andwhite line drawings, either covertly or overtly. Across both modalities, we found more left inferior frontal gyrus (LIFG) activity when the subjects named low-agreement pictures than when they named high-agreement pictures. No significant difference in head movement was detected between the two modalities. In Experiment 2, we replicated the effect of name agreement on LIFG activity during picture naming, using black-and-white photographs. These results provide further support for the idea that the LIFG mediates selection among competing alternatives and suggest a means for understanding the naming deficits observed in nonfluent aphasia.     

恐惧与厌恶情绪图片系统的编制：基于两种情绪的区分

基于恐惧与厌恶情绪刺激材料界定模糊的问题,实验一在总结前人研究中实验材料方面混淆恐惧和厌恶的基础上,通过问卷法完成了对恐惧与厌恶图片系统初步的搜集、整理工作;实验二通过进一步测评得到了具有良好信度的恐惧与厌恶情绪图片系统,图片系统中的恐惧与厌恶情绪很好的分离,且图片系统中动物、场景、物体三类图片的恐惧、厌恶程度均存在显著差异,可适用于需要不同种类情绪刺激的具体应用性研究。     

恐惧与厌恶情绪图片系统的编制：基于两种情绪的区分

基于恐惧与厌恶情绪刺激材料界定模糊的问题,实验一在总结前人研究中实验材料方面混淆恐惧和厌恶的基础上,通过问卷法完成了对恐惧与厌恶图片系统初步的搜集、整理工作;实验二通过进一步测评得到了具有良好信度的恐惧与厌恶情绪图片系统,图片系统中的恐惧与厌恶情绪很好的分离,且图片系统中动物、场景、物体三类图片的恐惧、厌恶程度均存在显著差异,可适用于需要不同种类情绪刺激的具体应用性研究。     

Episodic encoding and recognition of pictures and words: role of the human medial temporal lobes

In the present PET study, we examined brain activity related to processing of pictures and printed words in episodic memory. Our goal was to determine how the perceptual format of objects (verbal versus pictorial) is reflected in the neural organization of episodic memory for common objects. We investigated this issue in relation to encoding and recognition with a particular focus on medial temporal-lobe (MTL) structures. At encoding, participants saw pictures of objects or their written names and were asked to make semantic judgments. At recognition, participants made yes-no recognition judgments in four different conditions. In two conditions, target items were pictures of objects; these objects had originally been encoded either in picture or in word format. In two other conditions, target items were words; they also denoted objects originally encoded either as pictures or as words. Our data show that right MTL structures are differentially involved in picture processing during encoding and recognition. A posterior MTL region showed higher activation in response to the presentation of pictures than of words across all conditions. During encoding, this region may be involved in setting up a representation of the perceptual information that comprises the picture. At recognition, it may play a role in guiding retrieval processes based on the perceptual input, i.e. the retrieval cue. Another more anterior right MTL region was found to be differentially involved in recognition of objects that had been encoded as pictures, irrespective of whether the retrieval cue provided was pictorial or verbal in nature; this region may be involved in accessing stored pictorial representations. Our results suggest that left MTL structures contribute to picture processing only during encoding. Some regions in the left MTL showed an involvement in semantic encoding that was picture specific; others showed a task-specific involvement across pictures and words. Together, our results provide evidence that the involvement of some but not all MTL regions in episodic encoding and recognition is format specific.     

Effects of semantic priming on visual encoding of pictures

We investigated the effects of semantic priming on initial encoding of briefly presented pictures of objects and scenes. Pictures in four experiments were presented for varying durations and were followed immediately by a mask. In Experiments 1 and 2, pictures of simple objects were either preceded or not preceded by the object's category name (e.g., dog). In Experiment 1 we measured immediate object identification; in Experiment 2 we measured delayed old/new recognition in which targets and distractors were from the same categories. In Experiment 3 naturalistic scenes were either preceded or not preceded by the scene's category name (e.g., supermarket). We measured delayed recognition in which targets and distractors were described by the same category names. In Experiments 1-3, performance was better for primed than for unprimed pictures. Experiment 4 was similar to Experiment 2 in that we measured delayed recognition for simple objects. As in Experiments 1-3, a prime that preceded the object improved subsequent memory performance for the object. However, a prime that followed the object did not affect subsequent performance. Together, these results imply that priming leads to more efficient information acquisition. We offer a picture-processing model that accounts for these results. The model's central assumption is that knowledge of a picture's category (gist) increases the rate at which visual information is acquired from the picture.     

Dominance and context effects on activation of alternative homophone meanings

Two eyetracking-during-listening experiments showed frequency and context effects on fixation probability for pictures representing multiple meanings of homophones. Participants heard either an imperative sentence instructing them to look at a homophone referent (Experiment 1) or a declarative sentence that was either neutral or biased toward the homophone's subordinate meaning (Experiment 2). At homophone onset in both experiments, the participants viewed four pictures: (1) a referent of one homophone meaning, (2) a shape competitor for a nonpictured homophone meaning, and (3) two unrelated filler objects. In Experiment 1, meaning dominance affected looks to both the homophone referent and the shape competitor. In Experiment 2, as compared with neutral contexts, subordinate-biased contexts lowered the fixation probability for shape competitors of dominant meanings, but shape competitors still attracted more looks than would be expected by chance. We discuss the consistencies and discrepancies of these findings with the selective access and reordered access theories of lexical ambiguity resolution.     

Spatial asymmetries in viewing and remembering scenes: Consequences of an attentional bias?

Given a single fixation, memory for scenes containing salient objects near both the left and right view boundaries exhibited a rightward bias in boundary extension (Experiment 1). On each trial, a 500-msec picture and 2.5-sec mask were followed by a boundary adjustment task. Observers extended boundaries 5% more on the right than on the left. Might this reflect an asymmetric distribution of attention? In Experiments 2A and 2B, free viewing of pictures revealed that first saccades were more often leftward (62%) than rightward (38%). In Experiment 3, 500-msec pictures were interspersed with 2.5-sec masks. A subsequent object recognition memory test revealed better memory for left-side objects. Scenes were always mirror reversed for half the observers, thus ruling out idiosyncratic scene compositions as the cause of these asymmetries. Results suggest an unexpected leftward bias of attention that selectively enhanced the representations, causing a smaller boundary extension error and better object memory on the views’ left sides.     

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.     

The effects of humor on memory for non-sensical pictures

Two experiments investigated the effects of humor on memory for non-sensical pictures. Each picture was given three labels that differed in the degree of humor: high, low, and no humor labels. In Experiment 1, the humor of the picture labels was manipulated between participants. Participants were shown 30 pictures for 10 s each and were asked to rate the degree of humor of each picture. After the rating task, participants were asked to draw the pictures in an unexpected memory test. Performance in the memory test was best in the high humor label group, followed by the low and the no humor label groups. In Experiment 2, intention to learn (incidental versus intentional encoding tasks) as well as humor label was manipulated between the participants. In the incidental learning condition, the high humor group performed better than the low humor group, but in the intentional learning condition, there was no humor effect. The effects of humor on picture memory were discussed in terms of appraisal processing within a distinctiveness framework.     

Time course of attentional bias to emotional scenes in anxiety: Gaze direction and duration

Pictures of emotionally neutral, positive, and negative (threat- or harm-related) scenes were presented for 3 seconds, paired with nonemotional control pictures. The eye fixations of high and low trait anxiety participants were monitored. Intensity of stimulus emotionality was varied, with two levels of perceptual salience for each picture (colour vs. greyscale). Regardless of perceptual salience, high anxiety was associated with preferential attention: (a) towards all types of emotional stimuli in initial orienting, as revealed by a higher probability of first fixation on the emotional picture than on the neutral picture of a pair; (b) towards positive and harm stimuli in a subsequent stage of early engagement, as shown by longer viewing times during the first 500 ms following onset of the pictures; and with (c) attention away from (i.e., avoidance) harm stimuli in a later phase, as indicated by shorter viewing times and lower frequency of fixation during the last 1000 ms of picture exposure. This suggests that the nature of the attentional bias varies as a function of the time course in the processing of emotional pictures.     

Time course of attentional bias to emotional scenes in anxiety: Gaze direction and duration

Pictures of emotionally neutral, positive, and negative (threat‐ or harm‐related) scenes were presented for 3 seconds, paired with nonemotional control pictures. The eye fixations of high and low trait anxiety participants were monitored. Intensity of stimulus emotionality was varied, with two levels of perceptual salience for each picture (colour vs. greyscale). Regardless of perceptual salience, high anxiety was associated with preferential attention: (a) towards all types of emotional stimuli in initial orienting, as revealed by a higher probability of first fixation on the emotional picture than on the neutral picture of a pair; (b) towards positive and harm stimuli in a subsequent stage of early engagement, as shown by longer viewing times during the first 500 ms following onset of the pictures; and with (c) attention away from (i.e., avoidance) harm stimuli in a later phase, as indicated by shorter viewing times and lower frequency of fixation during the last 1000 ms of picture exposure. This suggests that the nature of the attentional bias varies as a function of the time course in the processing of emotional pictures.