Converging evidence for automatic perceptual processing in visual search.

This paper presents a commentary on an earlier paper in this journal entitled, car drivers' adjustments to cyclists at roundabouts. The focus of this commentary is on the visual search process that drivers engage in and how it is guided by top-down factors. However, these top-down factors are largely dependent on visual field objects that fit the driver's expectations. The author explores how these top-down expectancies develop and how they guide search behavior. An outline is presented containing improvements for self-explaining roads that the author posits would enhance the natural behavioral visual field search process, thereby enhancing traffic safety.

Standard models of visual search have focused upon asking participants to search for a single target in displays where the objects do not overlap one another, and where the objects are presented on a single depth plane. This stands in contrast to many everyday visual searches wherein variations in overlap and depth are the norm, rather than the exception. Here, we addressed whether presenting overlapping objects on different depths planes to one another can improve search performance. Across 4 different experiments using different stimulus types (opaque polygons, transparent polygons, opaque real-world objects, and transparent X-ray images), we found that depth was primarily beneficial when the displays were transparent, and this benefit arose in terms of an increase in response accuracy. Although the benefit to search performance only appeared in some cases, across all stimulus types, we found evidence of marked shifts in eye-movement behavior. Our results have important implications for current models and theories of visual search, which have not yet provided detailed accounts of the effects that overlap and depth have on guidance and object identification processes. Moreover, our results show that the presence of depth information could aid real-world searches of complex, overlapping displays. (PsycINFO Database Record

The present work clarifies the neural underpinning of inattentional deafness under high visual load. The findings of near-simultaneous load effects on both visual and auditory evoked responses suggest shared audiovisual processing capacity. Temporary depletion of shared capacity in perceptually demanding visual tasks leads to a momentary reduction in sensory processing of auditory stimuli, resulting in inattentional deafness. The dynamic "push-pull" pattern of load effects on visual and auditory processing furthers our understanding of both the neural mechanisms of attention and of cross-modal effects across visual and auditory processing. These results also offer an explanation for many previous failures to find cross-modal effects in experiments where the visual load effects may not have coincided directly with auditory sensory processing.

Can visual search be based on preconstancy representations of the scene--that is, ones in which accidental characteristics of the scene, such as shadows, point of view, and distance, have not yet been discounted? This question was addressed within the specific context of lightness constancy, the phenomenon that surface lightness is perceived as relatively unchanged despite changes in illumination conditions. Three experiments yielded evidence of preconstancy influence on visual search. This was true even when the preconstancy information that seemed to influence search was unavailable at a reportable level. The results suggest that visual search processes can be engaged before the processing that leads to the experienced perception of the scene is complete.

Evidence for inhibitory processes in visual search comes from studies using preview conditions, where responses to new targets are delayed if they carry a featural attribute belonging to the old distractor items that are currently being ignored-the negative carry-over effect (Braithwaite, Humphreys, & Hodsoll, 2003). We examined whether inhibition was applied in the same manner across different types of displays or whether the inhibitory weighting applied to different features varied with their utility for the search task. To test this, we present the first empirical investigation of negative carry-over effects under the ecologically valid conditions of dynamic visual search. Experiment 1 investigated preview search using dynamic moving and static displays. Detection was very poor when new targets carried the color of the old distractors, and this negative carry-over effect was significantly exaggerated with moving, compared with static, displays. Experiments 2a and 2b demonstrated that this effect could not be attributed to an increased role of preattentive grouping between new and old items for dynamic displays. Collectively, the findings suggest that feature-based inhibition contributes strongly to preview search through dynamic displays, and this leads to an amplified attentional blindness to new targets. The data specifically indicate that inhibitory processes in search differentially weight color and location in moving and static displays, and that feature-based inhibition may underlie many instances of sustained inattentional blindness in everyday life.

As an initial step toward developing a theory of visual concealment, we assessed whether people would use factors known to influence visual search difficulty when the degree of concealment of objects among distractors was varied. In Experiment 1, participants arranged search objects (shapes, emotional faces, and graphemes) to create displays in which the targets were in plain sight but were either easy or hard to find. Analyses of easy and hard displays created during Experiment 1 revealed that the participants reliably used factors known to influence search difficulty (e.g., eccentricity, target-distractor similarity, presence/absence of a feature) to vary the difficulty of search across displays. In Experiment 2, a new participant group searched for the targets in the displays created by the participants in Experiment 1. Results indicated that search was more difficult in the hard than in the easy condition. In Experiments 3 and 4, participants used presence versus absence of a feature to vary search difficulty with several novel stimulus sets. Taken together, the results reveal a close link between the factors that govern concealment and the factors known to influence search difficulty, suggesting that a visual search theory can be extended to form the basis of a theory of visual concealment.

In this study, we applied a transcranial magnetic stimulation (TMS) to investigate the temporal aspect for the functional processing of visual attention. Although it has been known that right posterior parietal cortex (PPC) in the brain has a role in certain visual search tasks, there is little knowledge about the temporal aspect of this area. Three visual search tasks that have different difficulties of task execution individually were carried out. These three visual search tasks are the “easy feature task,” the “hard feature task,” and the “conjunction task.” To investigate the temporal aspect of the PPC involved in the visual search, we applied various stimulus onset asynchronies (SOAs) and measured the reaction time of the visual search. The magnetic stimulation was applied on the right PPC or the left PPC by the figure-eight coil. The results show that the reaction times of the hard feature task are longer than those of the easy feature task. When SOA=150 ms, compared with no-TMS condition, there was a significant increase in target-present reaction time when TMS pulses were applied. We considered that the right PPC was involved in the visual search at about SOA=150 ms after visual stimulus presentation. The magnetic stimulation to the right PPC disturbed the processing of the visual search. However, the magnetic stimulation to the left PPC gives no effect on the processing of the visual search.

The primary aim of this study is to understand more about the perceptual-cognitive mechanisms underpinning the expert advantage in electrocardiogram (ECG) interpretation. While research has examined visual search processes in other aspects of medical decision making (e.g., radiology), this is the first study to apply the paradigm to ECG interpretation. The secondary aim is to explore the role that clinical history plays in influencing visual search behavior and diagnostic decision making. While clinical history may aid diagnostic decision making, it may also bias the visual search process. Ten final-year medical students and 10 consultant emergency medics were presented with 16 ECG traces (8 with clinical history that was not manipulated independently of case) while wearing eye tracking equipment. The ECGs represented common abnormalities encountered in emergency departments and were among those taught to final-year medical students. Participants were asked to make a diagnosis on each presented trace and report their level of diagnostic confidence. Experts made significantly faster, more accurate, and more confident diagnoses, and this advantage was underpinned by differences in visual search behavior. Specifically, experts were significantly quicker at locating the leads of critical importance. Contrary to our hypothesis, clinical history had no significant effect on the readers' ability to detect the abnormality or make an accurate diagnosis. Accurate ECG interpretation appears dependent on the perceptual skill of pattern recognition and specifically the time to fixate the critical lead(s). Therefore, there is potential clinical utility in developing perceptual training programs to train novices to detect abnormalities more effectively.

This call to revolution in theories of visual search does not go far enough. Treating fixations as uniform is an oversimplification that obscures the critical role of the mind. We remind readers that what happens during a fixation depends on mindset, as shown in studies of search strategy and of humans' ability to rapidly resume search following an interruption.

Attentional selection of a target presented among distractors can be indexed with an event-related potential (ERP) component known as the N2pc. Theoretical interpretation of the N2pc has suggested that it reflects a fundamental mechanism of attention that shelters the cortical representation of targets by suppressing neural activity stemming from distractors. Results from fields other than human electrophysiology, however, suggest that attention does not act solely through distractor suppression; rather, it modulates the processing of both target and distractors. We conducted four ERP experiments designed to investigate whether the N2pc reflects multiple attentional mechanisms. Our goal was to reconcile ostensibly conflicting outcomes obtained in electrophysiological studies of attention with those obtained using other methodologies. Participants viewed visual search arrays containing one target and one distractor. In Experiments 1 through 3, the distractor was isoluminant with the background, and therefore, did not elicit early lateralized ERP activity. This work revealed a novel contralateral ERP component that appears to reflect direct suppression of the cortical representation of the distractor. We accordingly name this component the distractor positivity (P(D)). In Experiment 4, an ERP component associated with target processing was additionally isolated. We refer to this component as the target negativity (N(T)). We believe that the N2pc reflects the summation of the P(D) and N(T), and that these discrete components may have been confounded in earlier electrophysiological studies. Overall, this study demonstrates that attention acts on both target and distractor representations, and that this can be indexed in the visual ERP.

Prior research has demonstrated that scene cues within real-world environments significantly expedite visual search tasks, particularly when co-occurrence objects—those that tend to appear concurrently and in close proximity—are present. The underlying mechanisms driving these enhancements remain a subject of ongoing debate. In this study, we recruited forty-five participants to perform a visual search task using real-world scene images, with conditions involving either the presence or absence of co-occurrence objects, while recording their right eye movements. Our findings revealed that the presence of co-occurrence objects exclusively enhanced search accuracy, without impacting response times or fixation durations. As participants engaged in repeated searches, their performance improved, characterized by increased accuracy, reduced response times, fewer fixations, and shorter fixation durations, applicable to both target objects and co-occurrence objects alike. Notably, the effect of co-occurrence objects remained consistent across search iterations, indicating no change with accumulated search experience. Collectively, these outcomes suggest a strategic role for co-occurrence objects in guiding visual search processes, potentially mediated through the spatial processing of target objects. This study contributes to our understanding of how contextual cues influence visual attention and search precision in complex environments.

The purpose of this study is to investigate the features of visual search at sport watching and of space information search shown at dominant observation, and accordingly, for the achievement of the purpose, the sport scenes were determined as objects for the conduct of eye-tracking experiment so that the change to observation factors may be examined based on the lapse of time. Even though this study was subject to the limitation that the sport scenes were the objects for the experiment. it is very meaningful in that the visual search process on sport scenes has been analyzed with a new analysis method which was grafted into the experimental environment where the eye-tracking was applied.BR First, in the process of sport-watching, subjects’ dominant observation was changed, when each subject showed a unique tendency. With the time-scope of 5 seconds, the space factors dominantly observed of each time scope were extracted and summarized so that the features of entire observation and the space factors dominantly observed of each subject were found. Second, with the consideration of observation time, it was possible to find out which key space factors were ruling dramatic scenes, when it was confirmed that the flow of observation time caused the space factors shown at dominant sections to change. It is very significant from what viewpoint the analysis results should be appreciated, and therefore the characteristics of dominance were estimated from the perspectives of 「Dominant Section」, 「Sport Marketing」 and 「Flow of Time Scope」, which analysis method has not been tried. So the systematization of this analysis method will enable the analysis of Space Observation Features from the viewpoints of conditions of sports, sport marketing and sport spectators. Third, for the analysis of this study contents, 4 hypotheses were established, which made it possible to confirm that the observation has much to do with the factors to space structure as stated above. For any marketing experiment with the object of sport condition in the future, the followings will be core issues: i) the scenes should be selected after the analysis of the correlation between Scene and Marketing when images shall be chosen, ii) the observation purpose should be clearly explained to the subjects and lastly iii) how the observation tendency changes by time should be examined for analysis.

Visual search has traditionally been studied in cognitive and perceptual paradigms, but little is known about how it contributes to visuomotor performance. We have developed a novel computational model to examine how three underlying processes of visual search (spatial planning, working memory, and peripheral visual processing) contribute to visual search during a visuomotor task. We show that deficits integrating spatial planning and working memory underlie abnormal performance in stroke survivors with frontoparietal damage.

Often, in inspection tasks, the O faces the problem of detecting abnormal target elements in an array of normal ones. From the known characteristics of the eye and from a simple theory of visual search, we have developed an equation relating the extent to which the target element deviates from normal to the time necessary to search for it. The equation fits data from a number of simple search experiments by us and by others. We think it should be of use in designing inspection systems. The equation also suggests how visual-search theory may be tested experimentally.

This study was designed to test whether information transmission between the perceptual and motor levels occurs continuously or in discrete steps. Ss performed visual search across nontargets that shared visual features with one of two possible targets, each assigned to a different response. In addition to reaction time, psychophysiological measures were used to assess the duration of target search and the onset of central and peripheral motor activity. Nontargets sharing features with a target selectively activated the response associated with that target, even when it was not present in the display. This suggests that information transmission to the motor level can consist of fine-grained visual information and that visual search and response selection occur in parallel.