Effect of Attention on the Detection and Identification of Masked Spatial Patterns

Perception ◽  
10.1068/p5276 ◽  
2005 ◽  
Vol 34 (3) ◽  
pp. 305-318 ◽  
Author(s):  
Endel Põder
Keyword(s):  
Visual Search ◽  
Spatial Patterns ◽  
Signal Detection Theory ◽  
Detection Task ◽  
Small Target ◽  
Crowding Effect ◽  
Identification Task ◽  
Set Size ◽  
Detection And Identification ◽  
Search Experiment

The effect of attention on the detection and identification of vertically and horizontally oriented Gabor patterns in the condition of simultaneous masking with obliquely oriented Gabors was studied. Attention was manipulated by varying the set size in a visual-search experiment. In the first experiment, small target Gabors were presented on the background of larger masking Gabors. In the detection task, the effect of set size was as predicted by unlimited-capacity signal detection theory. In the orientation identification task, increasing the set size from 1 to 8 resulted in a much larger decline in performance. The results of the additional experiments suggest that attention can reduce the crowding effect of maskers.

scholarly journals Role of symmetry and simplicity in shape disruption perception tasks

Psihologija ◽  
2012 ◽  
Vol 45 (1) ◽  
pp. 5-22 ◽  
Author(s):  
Marija Milisavljevic ◽  
Slobodan Markovic ◽  
Vasilije Gvozdenovic
Keyword(s):  
Visual Search ◽  
Reaction Time ◽  
Visual Perception ◽  
Reaction Times ◽  
Dominant Effect ◽  
Set Size ◽  
Dependent Variables ◽  
Search Experiment ◽  
And Performance

Purpose of the present research was further examination of roles of symmetry and complexity in visual perception tasks. We tested hypothesis from perceptual economy theory, and since we used shape disruptions as one of the stimulus characteristics we could also address Luccio?s two step theory concerning perception of shape disruptions on good forms. Four experiments were conducted, visual search and simultaneous and delayed matching. Symmetry and complexity were varied, as well as set size in visual search experiment. Dependent variables were reaction time and error number. In all four experiments, symmetry had dominant effect, while significant effect of complexity was registered only in Experiment 1. However, in first three experiments interaction of symmetry and complexity was also significant. Analysis of reaction times and performance suggested that our results follow the pattern suggested by perceptual economy, i.e. that symmetry is dominant in easier tasks, while complexity was significant in most difficult task. Our results couldn?t completely support Luccio?s assumption that shape disruption is better perceived on good forms, although it can?t be completely discarded.

scholarly journals What Can 1 Million Trials Tell Us About Visual Search?

1998 ◽  
Vol 9 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Jeremy M. Wolfe
Keyword(s):  
Retrospective Study ◽  
Visual Search ◽  
Reaction Time ◽  
Search Behavior ◽  
Set Size ◽  
Search Tasks ◽  
Search Processes ◽  
Search Experiment

In a typical visual search experiment, observers look through a set of items for a designated target that may or may not be present. Reaction time (RT) is measured as a function of the number of items in the display (set size), and inferences about the underlying search processes are based on the slopes of the resulting RT x Set Size functions. Most search experiments involve 5 to 15 subjects performing a few hundred trials each. In this retrospective study, I examine results from 2,500 experimental sessions of a few hundred trials each (approximately 1 million total trials). These data represent a wide variety of search tasks. The resulting picture of human search behavior requires changes in our theories of visual search.

scholarly journals Modeling individual variation in visual search with reinforcement learning

2020 ◽  
Author(s):  
Ben Lonnqvist ◽  
Micha Elsner ◽  
Amelia R. Hunt ◽  
Alasdair D F Clarke
Keyword(s):  
Visual Acuity ◽  
Reinforcement Learning ◽  
Visual Search ◽  
Individual Variation ◽  
Learning Model ◽  
Participant Preferences ◽  
Search Experiment ◽  
Reinforcement Learning Model ◽  
Specific Learning

Experiments on the efficiency of human search sometimes reveal large differences between individual participants. We argue that reward-driven task-specific learning may account for some of this variation. In a computational reinforcement learning model of this process, a wide variety of strategies emerge, despite all simulated participants having the same visual acuity. We conduct a visual search experiment, and replicate previous findings that participant preferences about where to search are highly varied, with a distribution comparable to the simulated results. Thus, task-specific learning is an under-explored mechanism by which large inter-participant differences can arise.

scholarly journals Looking ahead: When do you find the next item in foraging visual search?

2020 ◽  
Author(s):  
Anna Kosovicheva ◽  
Abla Alaoui-Soce ◽  
Jeremy Wolfe
Keyword(s):  
Visual Search ◽  
Eye Tracking ◽  
Real World ◽  
Final Experiment ◽  
Color Wheel ◽  
Visual Tasks ◽  
Search Experiment ◽  
Fixation Locations

Many real-world visual tasks involve searching for multiple instances of a target (e.g., picking ripe berries). What strategies do observers use when collecting items in this type of search? Do they wait to finish collecting the current item before starting to look for the next target, or do they search ahead for future targets? We utilized behavioral and eye tracking measures to distinguish between these two possibilities in foraging search. Experiment 1 used a color wheel technique in which observers searched for T shapes among L shapes while all items independently cycled through a set of colors. Trials were abruptly terminated, and observers reported both the color and location of the next target that they intended to click. Using observers’ color reports to infer target-finding times, we demonstrate that observers found the next item before the time of the click on the current target. We validated these results in Experiment 2 by recording fixation locations around the time of each click. Experiment 3 utilized a different procedure, in which all items were intermittently occluded during the trial. We then calculated a distribution of when targets were visible around the time of each click, allowing us to infer when they were most likely found. In a fourth and final experiment, observers indicated the locations of multiple future targets after the search was abruptly terminated. Together, our results provide converging evidence to demonstrate that observers can find the next target before collecting the current target and can typically forage 1-2 items ahead.

scholarly journals Visual search for complex objects: Set-size effects for faces, words and cars

2019 ◽  
Vol 162 ◽  
pp. 8-19 ◽  
Author(s):  
Jennifer Hemström ◽  
Andrea Albonico ◽  
Sarra Djouab ◽  
Jason J.S. Barton
Keyword(s):  
Visual Search ◽  
Size Effects ◽  
Complex Objects ◽  
Set Size ◽  
Set Size Effects

Serial Attention Mechanisms in Visual Search: A Direct Behavioral Demonstration

2002 ◽  
Vol 14 (7) ◽  
pp. 980-993 ◽  
Author(s):  
Emanuela Bricolo ◽  
Tiziana Gianesini ◽  
Alessandra Fanini ◽  
Claus Bundesen ◽  
Leonardo Chelazzi
Keyword(s):  
Visual Search ◽  
Size Effects ◽  
Conclusive Evidence ◽  
Steady Increase ◽  
Functional Neuroanatomy ◽  
Set Size ◽  
Behavioral Signatures ◽  
Series Of Experiments ◽  
The Individual ◽  
Set Size Effects

In visual search, inefficient performance of human observers is typically characterized by a steady increase in reaction time with the number of array elements—the so-called set-size effect. In general, set-size effects are taken to indicate that processing of the array elements depends on limited-capacity resources, that is, it involves attention. Contrasting theories have been proposed to account for this attentional involvement, however. While some theories have attributed set-size effects to the intervention of serial attention mechanisms, others have explained set-size effects in terms of parallel, competitive architectures. Conclusive evidence in favor of one or the other notion is still lacking. Especially in view of the wide use of visual search paradigms to explore the functional neuroanatomy of attentional mechanisms in the primate brain, it becomes essential that the nature of the attentional involvement in these paradigms be clearly defined at the behavioral level. Here we report a series of experiments showing that highly inefficient search indeed recruits serial attention deployment to the individual array elements. In addition, we describe a number of behavioral signatures of serial attention in visual search that can be used in future investigations to attest a similar involvement of serial attention in other search paradigms. We claim that only after having recognized these signatures can one be confident that truly serial mechanisms are engaged in a given visual search task, thus making it amenable for exploring the functional neuro-anatomy underlying its performance.

Effectiveness of Accommodative Aids in Reducing Empty Field Myopia in Visual Search

1978 ◽  
Vol 20 (6) ◽  
pp. 733-740 ◽  
Author(s):  
Michael L. Matthews ◽  
Robert G. Angus ◽  
Douglas G. Pearce
Keyword(s):  
Visual Search ◽  
Visual Detection ◽  
Field Performance ◽  
Detection Task ◽  
Performance Loss ◽  
Aircraft Cabin ◽  
Search Area ◽  
A Performance

When a visual detection task is performed with distant targets in the absence of adequate accommodative cues, a performance loss is obtained which has been attributed to empty field myopia. It is shown that in a visual search situation an accommodative aid located at optical infinity improves detection by approximately 30% over empty field performance. It is further demonstrated that such an aid may overcome the conflicting accommodative cues provided by proximal contours defining the search area, i.e., a situation that is analogous to the detection of distant targets by observers searching through aircraft cabin windows.

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