scholarly journals Visual search training benefits from the integrative effect of enhanced covert attention and optimized overt eye movements

2022 ◽  
Author(s):  
Qi Zhang ◽  
Zhibang Huang ◽  
Liang Li ◽  
Sheng Li
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Stimulus Onset ◽  
Covert Attention ◽  
Search Performance ◽  
Initiation Time ◽  
Training Effects ◽  
Trained Subjects ◽  
Scanning Time ◽  
Search Training

Visual search in a complex environment requires efficient discrimination between target and distractors. Training serves as an effective approach to improve visual search performance when the target does not automatically pop out from the distractors. In the present study, we trained subjects on a conjunction visual search task and examined the training effects in behavior and eye movement from Experiments 1 to 4. The results showed that training improved behavioral performance and reduced the number of saccades and overall scanning time. Training also increased the search initiation time before the first saccade and the proportion of trials in which the subjects correctly identified the target without any saccade, but these effects were modulated by stimulus' parameters. In Experiment 5, we replicated these training effects when eye movements and EEG signals were recorded simultaneously. The results revealed significant N2pc components after the stimulus onset (i.e., stimulus-locked) and before the first saccade (i.e., saccade-locked) when the search target was the trained one. These N2pc components can be considered as the neural signatures for the training-induced boost of covert attention to the trained target. The enhanced covert attention led to a beneficial tradeoff between search initiation time and the number of saccades as a small amount of increase in search initiation time could result in a larger reduction in scanning time. These findings suggest that the enhanced covert attention to target and optimized overt eye movements are coordinated together to facilitate visual search training.

scholarly journals The effects of induced optical blur on visual search performance and training

2021 ◽  
pp. 174702182110502
Author(s):  
Azuwan Musa ◽  
Alison R Lane ◽  
Amanda Ellison
Keyword(s):  
Visual Acuity ◽  
Visual Search ◽  
Visual Field Loss ◽  
Search Performance ◽  
Searching Behaviour ◽  
Feature Search ◽  
Search Tasks ◽  
Search Speed ◽  
Search Training ◽  
Optical Blur

Visual search is a task often used in the rehabilitation of patients with cortical and non-cortical visual pathologies such as visual field loss. Reduced visual acuity is often comorbid with these disorders, and it remains poorly defined how low visual acuity may affect a patient’s ability to recover visual function through visual search training. The two experiments reported here investigated whether induced blurring of vision (from 6/15 to 6/60) in a neurotypical population differentially affected various types of feature search tasks, whether there is a minimal acceptable level of visual acuity required for normal search performance, and whether these factors affected the degree to which participants could improve with training. From the results, it can be seen that reducing visual acuity did reduce search speed, but only for tasks where the target was defined by shape or size (not colour), and only when acuity was worse than 6/15. Furthermore, searching behaviour was seen to improve with training in all three feature search tasks, irrespective of the degree of blurring that was induced. The improvement also generalised to a non-trained search task, indicating that an enhanced search strategy had been developed. These findings have important implications for the use of visual search as a rehabilitation aid for partial visual loss, indicating that individuals with even severe comorbid blurring should still be able to benefit from such training.

scholarly journals No advantage for separating overt and covert attention in visual search

2020 ◽  
Author(s):  
Joseph MacInnes ◽  
Ómar I. Jóhannesson ◽  
Andrey Chetverikov ◽  
Arni Kristjansson
Keyword(s):  
Information Processing ◽  
Visual Search ◽  
Change Blindness ◽  
Task Demands ◽  
Covert Attention ◽  
Search Performance ◽  
Overt Attention ◽  
Complex Scenes ◽  
Improved Performance ◽  
Gaze Position

We move our eyes roughly three times every second while searching complex scenes, but covert attention helps to guide where we allocate those overt fixations. Covert attention may be allocated reflexively or voluntarily, and speeds the rate of information processing at the attended location. Reducing access to covert attention hinders performance, but it is not known to what degree the locus of covert attention is tied to the current gaze position. We compared visual search performance in a traditional gaze contingent display with a second task where a similarly sized contingent window is controlled with a mouse allowing a covert aperture to be controlled independently from overt gaze. Larger apertures improved performance for both mouse and gaze contingent trials suggesting that covert attention was beneficial regardless of control type. We also found evidence that participants used the mouse controlled aperture independently of gaze position, suggesting that participants attempted to untether their covert and overt attention when possible. This untethering manipulation, however, resulted in an overall cost to search performance, a result at odds with previous results in a change blindness paradigm. Untethering covert and overt attention may therefore have costs or benefits depending on the task demands in each case.

scholarly journals Seeing Beyond Salience and Guidance: The Role of Bias and Decision in Visual Search

Vision ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 46
Author(s):  
Alasdair D. F. Clarke ◽  
Anna Nowakowska ◽  
Amelia R. Hunt
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Signal Detection ◽  
Future Research ◽  
Search Performance ◽  
Guided Search ◽  
Vision Science ◽  
Search Tasks ◽  
Field Of Vision

Visual search is a popular tool for studying a range of questions about perception and attention, thanks to the ease with which the basic paradigm can be controlled and manipulated. While often thought of as a sub-field of vision science, search tasks are significantly more complex than most other perceptual tasks, with strategy and decision playing an essential, but neglected, role. In this review, we briefly describe some of the important theoretical advances about perception and attention that have been gained from studying visual search within the signal detection and guided search frameworks. Under most circumstances, search also involves executing a series of eye movements. We argue that understanding the contribution of biases, routines and strategies to visual search performance over multiple fixations will lead to new insights about these decision-related processes and how they interact with perception and attention. We also highlight the neglected potential for variability, both within and between searchers, to contribute to our understanding of visual search. The exciting challenge will be to account for variations in search performance caused by these numerous factors and their interactions. We conclude the review with some recommendations for ways future research can tackle these challenges to move the field forward.

The Influence of Brightness Highlighting on Eye Movements within a Cockpit Display of Traffic Information

2005 ◽  
Vol 49 (17) ◽  
pp. 1644-1648
Author(s):  
Min-Ju Liao ◽  
Stacy Granada ◽  
Walter W. Johnson
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Search Task ◽  
Traffic Information ◽  
Search Performance ◽  
Detection Time ◽  
Current Experiment ◽  
Time Analysis ◽  
Cockpit Display ◽  
Eye Fixations

Several experiments were conducted to examine the effect of brightness highlighting on search of a target aircraft among distractor aircraft within a cockpit display of traffic information (CDTI). The present experiment partially replicated the design of one of these experiments, adding an examination of eye movements. The display presented homogenous all bright, all dim, or mixed bright and dim aircraft. Within the mixed display, target aircraft were non-predictive and either bright or dim. Results showed that with the mixed display, participants yielded slower detection times, exhibited more eye fixations, and searched with longer paths, compared to the homogenous all bright or dim displays. The duration of the fixation and the speed of eye movements did not show any difference between the homogeneous and mixed displays. The present detection time analysis did not replicate previous experimental results and this is likely due to the fewer trials given in the current experiment. The present results demonstrated how using highlighting to segregate information domains may impose costs on visual search performance in the early stages of a search task.

scholarly journals Eye movements reflect expertise development in hybrid search

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Megan H. Papesh ◽  
Michael C. Hout ◽  
Juan D. Guevara Pinto ◽  
Arryn Robbins ◽  
Alexis Lopez
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Response Times ◽  
Search Performance ◽  
Hybrid Search ◽  
Domain Specific ◽  
Visual Span ◽  
Change Behavior ◽  
Fixation Probabilities ◽  
Study Participants

AbstractDomain-specific expertise changes the way people perceive, process, and remember information from that domain. This is often observed in visual domains involving skilled searches, such as athletics referees, or professional visual searchers (e.g., security and medical screeners). Although existing research has compared expert to novice performance in visual search, little work has directly documented how accumulating experiences change behavior. A longitudinal approach to studying visual search performance may permit a finer-grained understanding of experience-dependent changes in visual scanning, and the extent to which various cognitive processes are affected by experience. In this study, participants acquired experience by taking part in many experimental sessions over the course of an academic semester. Searchers looked for 20 categories of targets simultaneously (which appeared with unequal frequency), in displays with 0–3 targets present, while having their eye movements recorded. With experience, accuracy increased and response times decreased. Fixation probabilities and durations decreased with increasing experience, but saccade amplitudes and visual span increased. These findings suggest that the behavioral benefits endowed by expertise emerge from oculomotor behaviors that reflect enhanced reliance on memory to guide attention and the ability to process more of the visual field within individual fixations.

Covert Visual Search

2014 ◽  
Vol 8 (3) ◽  
pp. 13-28 ◽  
Author(s):  
Ulrich Engelke ◽  
Andreas Duenser ◽  
Anthony Zeater
Keyword(s):  
Visual Search ◽  
Response Times ◽  
Task Complexity ◽  
Error Rates ◽  
Covert Attention ◽  
Integration Theory ◽  
Search Performance ◽  
Cognitive Computing ◽  
Human Machine Interaction ◽  
Guided Search

Selective attention is an important cognitive resource to account for when designing effective human-machine interaction and cognitive computing systems. Much of our knowledge about attention processing stems from search tasks that are usually framed around Treisman's feature integration theory and Wolfe's Guided Search. However, search performance in these tasks has mainly been investigated using an overt attention paradigm. Covert attention on the other hand has hardly been investigated in this context. To gain a more thorough understanding of human attentional processing and especially covert search performance, the authors have experimentally investigated the relationship between overt and covert visual search for targets under a variety of target/distractor combinations. The overt search results presented in this work agree well with the Guided Search studies by Wolfe et al. The authors show that the response times are considerably more influenced by the target/distractor combination than by the attentional search paradigm deployed. While response times are similar between the overt and covert search conditions, they found that error rates are considerably higher in covert search. They further show that response times between participants are stronger correlated as the search task complexity increases. The authors discuss their findings and put them into the context of earlier research on visual search.

Distractor Ratio Influences Patterns of Eye Movements during Visual Search

Perception ◽  
10.1068/p2933 ◽  
2000 ◽  
Vol 29 (2) ◽  
pp. 241-250 ◽  
Author(s):  
Jiye Shen ◽  
Eyal M Reingold ◽  
Marc Pomplun
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Search Task ◽  
Search Model ◽  
Search Performance ◽  
Manual Response ◽  
Guided Search ◽  
Different Types ◽  
Conjunctive Search

We examined the flexibility of guidance in a conjunctive search task by manipulating the ratios between different types of distractors. Participants were asked to decide whether a target was present or absent among distractors sharing either colour or shape. Results indicated a strong effect of distractor ratio on search performance. Shorter latency to move, faster manual response, and fewer fixations per trial were observed at extreme distractor ratios. The distribution of saccadic endpoints also varied flexibly as a function of distractor ratio. When there were very few same-colour distractors, the saccadic selectivity was biased towards the colour dimension. In contrast, when most of the distractors shared colour with the target, the saccadic selectivity was biased towards the shape dimension. Results are discussed within the framework of the guided search model.

Eye movements are an important part of the story, but not the whole story

2017 ◽  
Vol 40 ◽  
Author(s):  
Kyle R. Cave
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Covert Attention ◽  
Full Account ◽  
Visual Targets ◽  
Selection Mechanisms

AbstractSome previous accounts of visual search have emphasized covert attention at the expense of eye movements, and others have focused on eye movements while ignoring covert attention. Both selection mechanisms are likely to contribute to many searches, and a full account of search will probably need to explain how the two interact to find visual targets.

scholarly journals Mind-Wandering: What Can We Learn from Eye Movements?

2020 ◽  
Author(s):  
Han Zhang
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Cognitive Processing ◽  
Visual Processing ◽  
Scene Perception ◽  
Mind Wandering ◽  
Task Demands ◽  
Search Performance ◽  
Wide Range ◽  
Irrelevant Distractors

Mind-wandering (MW) is ubiquitous and is associated with reduced performance across a wide range of tasks. Recent studies have shown that MW can be related to changes in gaze parameters. In this dissertation, I explored the link between eye movements and MW in three different contexts that involve complex cognitive processing: visual search, scene perception, and reading comprehension. Study 1 examined how MW affects visual search performance, particularly the ability to suppress salient but irrelevant distractors during visual search. Study 2 used a scene encoding task to study how MW affects how eye movements change over time and their relationship with scene content. Study 3 examined how MW affects readers’ ability to detect semantic incongruities in the text and make necessary revisions of their understanding as they read jokes. All three studies showed that MW was associated with decreased task performance at the behavioral level (e.g., response time, recognition, and recall). Eye-tracking further showed that these behavioral costs can be traced to deficits in specific cognitive processes. The final chapter of this dissertation explored whether there are context-independent eye movement features of MW. MW manifests itself in different ways depending on task characteristics. In tasks that require extensive sampling of the stimuli (e.g., reading and scene viewing), MW was related to a global reduction in visual processing. But this was not the case for the search task, which involved speeded, simple visual processing. MW was instead related to increased looking time on the target after it was already located. MW affects the coupling between cognitive efforts and task demands, but the nature of this decoupling depends on the specific features of particular tasks.

Caudal Prefrontal Cortex

2021 ◽  
pp. 153-190
Author(s):  
Richard E. Passingham
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Covert Attention ◽  
Frontal Eye Field ◽  
Top Down ◽  
Cluttered Environment ◽  
Eye Field ◽  
Sensory Responses ◽  
Search For Objects ◽  
Oculomotor Nuclei

The caudal prefrontal (PF) cortex supports the visual search for objects such as foods both through eye movements and covert attention, and its connections explain how it can do this. The caudal PF cortex, which includes the frontal eye field, has connections with both the dorsal and ventral visual streams. The direction of eye movements depends on its connections with the superior colliculus and oculomotor nuclei. Covert attention depends on enhanced sensory responses that are mediated through top-down interactions with posterior sensory areas. Along with the granular parts of the orbital PF cortex, the caudal PF cortex evolved in early primates. Together, these two new areas led to improvements in searching for and evaluating objects that are hidden in a cluttered environment.

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