Scene exploration with Fourier-filtered peripheral information.

In a previous moving-window study it was found that scene exploration benefits more from peripheral information of high spatial frequency than of low spatial frequency. In the present study, degraded versions of realistic scenes were presented peripherally during the initial 150 ms of fixations, while the undegraded scene was presented foveally. The undegraded version of the scene was visible both foveally and peripherally during the later part of fixations. During the initial 150 ms, the peripheral part of scenes was low-pass, bandpass, or high-pass filtered, blanked, or decreased in luminance. In a no-change condition, the undegraded scene was presented throughout the whole fixation. Participants freely explored the scenes in the context of an object-decision task. It was found that degrading peripheral information during the initial part of fixations had minimal effect on scene exploration. No reliable differences were found among the three filter types. The results indicate that, in the context of an object-search task, peripheral information is of minor importance during the initial part of fixations.     

Change detection in the flicker paradigm: The role of fixation position within the scene

Eye movements were monitored while participants performed a change detection task with images of natural scenes. An initial and a modified scene image were displayed in alternation, separated by a blank interval (flicker paradigm). In the modified image, a single target object was changed either by deleting that object from the scene or by rotating that object 90 degrees in depth. In Experiment 1, fixation position at detection was more likely to be in the target object region than in any other region of the scene. In Experiment 2, participants detected scene changes more accurately, with fewer false alarms, and more quickly when allowed to move their eyes in the scene than when required to maintain central fixation. These data suggest a major role for fixation position in the detection of changes to natural scenes across discrete views.     

Racial fantasies and the primal scene of miscegenation

The primal scene, theorized by Freud in his case history of the Wolf Man, is a fantasy scenario thoroughly embedded in social relations. While pursuing his analysis of oedipal structures in the Wolf Man's case history, Freud overlooked social relations, downplaying the importance of racial and class difference in the Wolf Man's sexual etiology. In this essay, I trace the circulation of two fantasy structures: 'the primal scene of miscegenation' and 'A black man is being beaten,' both of which structure desire in both Freud 's era and our own. I interpret Fanon's work on racial subjectivity alongside Freud 's theory of fantasy to elucidate the interconnected nature of racial and sexual difference in both Freud and Fanon's theories. The racial fantasies proposed in this essay have application to clinical settings, where they may structure transference and countertransference.     

Pictures in mind: initial encoding of object properties varies with the realism of the scene stimulus

A fundamental question in perception is how we visually encode and retain information about a complex scene in order to allow effective operation within it. Interestingly, the stimuli used to investigate scene perception have varied greatly between studies, ranging from line drawings to coloured drawings, computer-generated scenes, photographs, and real scenes. Are findings from these different types of scene stimulus equally ecologically valid? Two experiments are reported that address this issue. In the first we compared photographic and non-photographic scenes and found that observers perform better in questions testing object memory when viewing photographs, suggesting an initial benefit for encoding information from photographs. In the second we found that whether or not non-photographic scenes obeyed realistic scene-organising properties influenced object-memory formation. Effects varied for the different question types, but again were most prominent early in viewing. We conclude that in the search for an understanding of everyday scene perception we must be very careful in our choice of scene stimuli and in our interpretation of findings from the laboratory.     

Recognition and attention guidance during contextual cueing in real-world scenes: evidence from eye movements

When confronted with a previously encountered scene, what information is used to guide search to a known target? We contrasted the role of a scene's basic-level category membership with its specific arrangement of visual properties. Observers were repeatedly shown photographs of scenes that contained consistently but arbitrarily located targets, allowing target positions to be associated with scene content. Learned scenes were then unexpectedly mirror reversed, spatially translating visual features as well as the target across the display while preserving the scene's identity and concept. Mirror reversals produced a cost as the eyes initially moved toward the position in the display in which the target had previously appeared. The cost was not complete, however; when initial search failed, the eyes were quickly directed to the target's new position. These results suggest that in real-world scenes, shifts of attention are initially based on scene identity, and subsequent shifts are guided by more detailed information regarding scene and object layout.     

Recognition and attention guidance during contextual cueing in real-world scenes: Evidence from eye movements

When confronted with a previously encountered scene, what information is used to guide search to a known target? We contrasted the role of a scene's basic-level category membership with its specific arrangement of visual properties. Observers were repeatedly shown photographs of scenes that contained consistently but arbitrarily located targets, allowing target positions to be associated with scene content. Learned scenes were then unexpectedly mirror reversed, spatially translating visual features as well as the target across the display while preserving the scene's identity and concept. Mirror reversals produced a cost as the eyes initially moved toward the position in the display in which the target had previously appeared. The cost was not complete, however; when initial search failed, the eyes were quickly directed to the target's new position. These results suggest that in real-world scenes, shifts of attention are initially based on scene identity, and subsequent shifts are guided by more detailed information regarding scene and object layout.     

Detection and Identification of Change in Naturalistic Scenes

Research using change detection paradigms has demonstrated that only limited scene information remains available for conscious report following initial inspection of a scene. Previous researchers have found higher change identification rates for deletions of parts of objects in line drawings of scenes than additions. Other researchers, however, have found an asymmetry in the opposite direction for addition/deletion of whole objects in line drawings of scenes. Experiment 1 investigated subjects' accuracy in detecting and identifying changes made to successive views of high quality photographs of naturalistic scenes that involved the addition and deletion of objects, colour changes to objects, and changes to the spatial location of objects. Identification accuracy for deletions from scenes was highest, with lower identification rates for object additions and colour changes, and the lowest rates for identification of location changes. Data further suggested that change identification rates for the presence/absence of objects were a function of the number of identical items present in the scene. Experiment 2 examined this possibility further, and also investigated whether the higher identification rates for deletions found in Experiment 1 were found for changes involving whole objects or parts of objects. Results showed higher identification rates for deletions, but only where a unique object was deleted from a scene. The presence of an identical object in the scene abolished this deletion identification advantage. Results further showed that the deletion/addition asymmetry occurs both when the objects are parts of a larger object and when they are entire objects in the scene.     

The relative contribution of scene context and target features to visual search in scenes

Many experiments have shown that knowing a targets visual features improves search performance over knowing the target name. Other experiments have shown that scene context can facilitate object search in natural scenes. In this study, we investigated how scene context and target features affect search performance. We examined two possible sources of information from scene context—the scenes gist and the visual details of the scene—and how they potentially interact with target-feature information. Prior to commencing search, participants were shown a scene and a target cue depicting either a picture or the category name (or no-information control). Using eye movement measures, we investigated how the target features and scene context influenced two components of search: early attentional guidance processes and later verification processes involved in the identification of the target. We found that both scene context and target features improved guidance, but that target features also improved speed of target recognition. Furthermore, we found that a scenes visual details played an important role in improving guidance, much more so than did the scenes gist alone.     

Cluster Analysis Examination of Serial Killer Profiling Categories: A Bottom‐Up Approach

Two studies explored the validity of dichotomous classification of organised/disorganised serial killers and the four typologies (visionary, mission, hedonistic, and power/control) adopted by the Federal Bureau of Investigation (FBI). Tables documenting crime scene criteria were devised consisting of 50 typifying different crime scenes (Study 1) and 48 crime scenes (taken from the 50 crime scene criteria) with a further 10 motive‐based crime scene criteria (Study 2). Adopting content analysis, crime scenes depicted for 40 (Study 1) and 40 (Study 2) serial killers using secondary sources of data were dichotomously coded for the presence or absence of the crime scene criteria. These data were inputted for agglomerative hierarchical cluster using Ward's method as the clustering algorithm. Differences in the nature of clusters were found for male and female serial killers; however, there was no empirical support for the organised/disorganised classifications or the four typologies. The ‘bottom‐up’ approach resulted in clusters from the different crime scene criteria that helped to understand how these criteria were associated within the serial killer cohort considered. It is concluded that the resulting clusters in both studies support the notion of there being an underlying organised element to most serial murder and that serial murders differ according to the nature of disorganised crime scene criteria present. Copyright © 2011 John Wiley & Sons, Ltd.     

Guidance of attention to objects and locations by long-term memory of natural scenes

Four flicker change-detection experiments demonstrate that scene-specific long-term memory guides attention to both behaviorally relevant locations and objects within a familiar scene. Participants performed an initial block of change-detection trials, detecting the addition of an object to a natural scene. After a 30-min delay, participants performed an unanticipated 2nd block of trials. When the same scene occurred in the 2nd block, the change within the scene was (a) identical to the original change, (b) a new object appearing in the original change location, (c) the same object appearing in a new location, or (d) a new object appearing in a new location. Results suggest that attention is rapidly allocated to previously relevant locations and then to previously relevant objects. This pattern of locations dominating objects remained when object identity information was made more salient. Eye tracking verified that scene memory results in more direct scan paths to previously relevant locations and objects. This contextual guidance suggests that a high-capacity long-term memory for scenes is used to insure that limited attentional capacity is allocated efficiently rather than being squandered.     

What's Scene and Not Seen: Influences of Movement and Task Upon What We See

Studies concerning the processing of natural scenes using eye movement equipment have revealed that observers retain surprisingly little information from one fixation to the next. Other studies, in which fixation remained constant while elements within the scene were changed, have shown that, even without refixation, objects within a scene are surprisingly poorly represented. Although this effect has been studied in some detail in static scenes, there has been relatively little work on scenes as we would normally experience them, namely dynamic and ever changing. This paper describes a comparable form of change blindness in dynamic scenes, in which detection is performed in the presence of simulated observer motion. The study also describes how change blindness is affected by the manner in which the observer interacts with the environment, by comparing detection performance of an observer as the passenger or driver of a car. The experiments show that observer motion reduces the detection of orientation and location changes, and that the task of driving causes a concentration of object analysis on or near the line of motion, relative to passive viewing of the same scene.     

Life and Death Matters: Losing a Sense of the Value of Human Beings

The essay combines a specific and a more general theme. In attacking ‘the doctrine of the sanctity of human life’ Singer takes himself thereby to be opposing the conviction that human life has special value. I argue that this conviction goes deep in our lives in many ways that do not depend on what Singer identifies as central to that ‘doctrine’, and that his attack therefore misses its main target. I argue more generally that Singer’s own moral philosophy affords only an impoverished and distorted sense of the value of human life and human beings. In purporting to dig below the supposedly illusion–ridden surface of our thinking about value, Singer in fact often leads us away from the robust terrain of our lived experience into rhetorical, and sometimes brutal, fantasy.     

Optimal and preferred eye landing positions in objects and scenes

Viewing position effects are commonly observed in reading, but they have only rarely been investigated in object perception or in the realistic context of a natural scene. In two experiments, we explored where people fixate within photorealistic objects and the effects of this landing position on recognition and subsequent eye movements. The results demonstrate an optimal viewing position—objects are processed more quickly when fixation is in the centre of the object. Viewers also prefer to saccade to the centre of objects within a natural scene, even when making a large saccade. A central landing position is associated with an increased likelihood of making a refixation, a result that differs from previous reports and suggests that multiple fixations within objects, within scenes, occur for a range of reasons. These results suggest that eye movements within scenes are systematic and are made with reference to an early parsing of the scene into constituent objects.     

Content,not context,facilitates memory for real-world scenes

ABSTRACT

Can eye movements tell us whether people will remember a scene? In order to investigate the link between eye movements and memory encoding and retrieval, we asked participants to study photographs of real-world scenes while their eye movements were being tracked. We found eye gaze patterns during study to be predictive of subsequent memory for scenes. Moreover, gaze patterns during study were more similar to gaze patterns during test for remembered than for forgotten scenes. Thus, eye movements are indeed indicative of scene memory. In an explicit test for context effects of eye movements on memory, we found recognition rate to be unaffected by the disruption of spatial and/or temporal context of repeated eye movements. Therefore, we conclude that eye movements cue memory by selecting and accessing the most relevant scene content, regardless of its spatial location within the scene or the order in which it was selected.     

Parafoveal semantic processing of emotional visual scenes

The authors investigated whether emotional pictorial stimuli are especially likely to be processed in parafoveal vision. Pairs of emotional and neutral visual scenes were presented parafoveally (2.1 degrees or 2.5 degrees of visual angle from a central fixation point) for 150-3,000 ms, followed by an immediate recognition test (500-ms delay). Results indicated that (a) the first fixation was more likely to be placed onto the emotional than the neutral scene; (b) recognition sensitivity (A') was generally higher for the emotional than for the neutral scene when the scenes were paired, but there were no differences when presented individually; and (c) the superior sensitivity for emotional scenes survived changes in size, color, and spatial orientation, but not in meaning. The data suggest that semantic analysis of emotional scenes can begin in parafoveal vision in advance of foveal fixation.     

Object–scene inconsistencies do not capture gaze: evidence from the flash-preview moving-window paradigm

In the present study, we investigated the influence of object-scene relationships on eye movement control during scene viewing. We specifically tested whether an object that is inconsistent with its scene context is able to capture gaze from the visual periphery. In four experiments, we presented rendered images of naturalistic scenes and compared baseline consistent objects with semantically, syntactically, or both semantically and syntactically inconsistent objects within those scenes. To disentangle the effects of extrafoveal and foveal object-scene processing on eye movement control, we used the flash-preview moving-window paradigm: A short scene preview was followed by an object search or free viewing of the scene, during which visual input was available only via a small gaze-contingent window. This method maximized extrafoveal processing during the preview but limited scene analysis to near-foveal regions during later stages of scene viewing. Across all experiments, there was no indication of an attraction of gaze toward object-scene inconsistencies. Rather than capturing gaze, the semantic inconsistency of an object weakened contextual guidance, resulting in impeded search performance and inefficient eye movement control. We conclude that inconsistent objects do not capture gaze from an initial glimpse of a scene.     

Direct control of fixation times in scene viewing: Evidence from analysis of the distribution of first fixation duration

Participants' eye movements were monitored in two scene viewing experiments that manipulated the task-relevance of scene stimuli and their availability for extrafoveal processing. In both experiments, participants viewed arrays containing eight scenes drawn from two categories. The arrays of scenes were either viewed freely (Free Viewing) or in a gaze-contingent viewing mode where extrafoveal preview of the scenes was restricted (No Preview). In Experiment 1a, participants memorized the scenes from one category that was designated as relevant, and in Experiment 1b, participants chose their preferred scene from within the relevant category. We examined first fixations on scenes from the relevant category compared to the irrelevant category (Experiments 1a and 1b), and those on the chosen scene compared to other scenes not chosen within the relevant category (Experiment 1b). A survival analysis was used to estimate the first discernible influence of the task-relevance on the distribution of first-fixation durations. In the free viewing condition in Experiment 1a, the influence of task relevance occurred as early as 81 ms from the start of fixation. In contrast, the corresponding value in the no preview condition was 254 ms, demonstrating the crucial role of extrafoveal processing in enabling direct control of fixation durations in scene viewing. First fixation durations were also influenced by whether or not the scene was eventually chosen (Experiment 1b), but this effect occurred later and affected fewer fixations than the effect of scene category, indicating that the time course of scene processing is an important variable mediating direct control of fixation durations.     

Real-world schemata and scene recognition in adults and children

Recognition memory for previously seen multiobject scenes was examined for different types of contextual arrangements between objects in the scenes. It was found that organized scenes with novel but possible interobject relations were recognized more accurately than either organized scenes with familiar interobject relations or unorganized scenes with impossible interobject relations. This finding was obtained for adults, 8- to 10-year-old children, and 5- to 8-year-old children who indicated concrete-operational ability in Piaget’s conservation-of-liquid quantity task. The results were interpreted in conjunction with a two-stage model of scene processing involving the formation of a schema to represent a scene (Stage 1), and the operation of the schema in governing the further processing of detailed information in the scene (Stage 2). It was concluded that preoperational children can form schemata to represent organized scenes (Stage 1), but it is not until the emergence of concrete operations that these schemata become operational with respect to guiding the further processing of information in the scene (Stage 2).     

Using real-world scenes as contextual cues for search

Research on contextual cueing has demonstrated that with simple arrays of letters and shapes, search for a target increases in efficiency as associations between a search target and its surrounding visual context are learned. We investigated whether the visual context afforded by repeated exposure to real-world scenes can also guide attention when the relationship between the scene and a target position is arbitrary. Observers searched for and identified a target letter embedded in photographs of real-world scenes. Although search time within novel scenes was consistent across trials, search time within repeated scenes decreased across repetitions. Unlike previous demonstrations of contextual cueing, however, memory for scene-target covariation was explicit. In subsequent memory tests, observers recognized repeated contexts more often than those that were presented once and displayed superior recall of target position within the repeated scenes. In addition, repetition of inverted scenes, which made the scene more difficult to identify, produced a markedly reduced rate of learning, suggesting semantic information concerning object and scene identity are used to guide attention.