scholarly journals Perception of illusory contour figures: Microgenetic analysis

Psihologija ◽  
2004 ◽  
Vol 37 (4) ◽  
pp. 451-481 ◽  
Author(s):  
Vasilije Gvozdenovic
Keyword(s):  
Visual Search ◽  
Visual Attention ◽  
Illusory Contour ◽  
Feature Binding ◽  
Integration Theory ◽  
Search Tasks ◽  
Time Period ◽  
Priming Phase ◽  
Feature Integration Theory ◽  
Two Phases

Microgenetic analysis was used to investigate perception of illusory contour figures which represent whole, completed forms on the basis of segmented, incomplete stimulation. The analysis provided an experimental approach to this phenomenon which was standardly investigated phenomenologically. Experimental procedure consisted of two phases: a) priming phase and b) test phase which consisted of visual search task. Two types of visual search tasks were applied: (i) classic detection, in which subjects were detecting presence or absence of the target stimuli and (ii) two-alternative forced choice, 2AFC, in which subjects performed discrimination between two concurrent targets (target A vs. target B). Variation of exposition of prim stimuli was used as an indication of the percept formation period. Concepts like early vision, visual attention and feature binding were investigated. Four experiments were conducted. Their outcome showed that (i) perception of amodal figure requires visual attention, (ii) features binding precedes spatial attention and (iii) time period of percept formation is dependent of task properties and varies between 50 - 150 ms. Some results obtained in this research could be explained by feature-integration theory (Treisman & Gelade, 1980; Treisman, 1986). Furthermore, percept formation period data comply with data acquired in Elliott & M?ller's psychophysical research (1998).

scholarly journals Visual Search for Feature and Conjunction Targets with an Attention Deficit

1993 ◽  
Vol 5 (4) ◽  
pp. 436-452 ◽  
Author(s):  
Martin Arguin ◽  
Yves Joanette ◽  
Patrick Cavanagh
Keyword(s):  
Visual Search ◽  
Visual Attention ◽  
Attention Deficit ◽  
Feature Integration ◽  
Integration Theory ◽  
Target Orientation ◽  
Search Tasks ◽  
Attention Disorder ◽  
Feature Target ◽  
Marked Deficit

Brain-damaged subjects who had previously been identified as suffering from a visual attention deficit for contralesional stimulation were tested on a series of visual search tasks. The experiments examined the hypothesis that the processing of single features is preattentive but that feature integration, necessary for the correct perception of conjunctions of features, requires attention (Treisman & Gelade, 1980 Treisman & Sato, 1990). Subjects searched for a feature target (orientation or color) or for a conjunction target (orientation and color) in unilateral displays in which the number of items presented was variable. Ocular fixation was controlled so that trials on which eye movements occurred were cancelled. While brain-damaged subjects with a visual attention disorder (VAD subjects) performed similarly to normal controls in feature search tasks, they showed a marked deficit in conjunction search. Specifically, VAD subjects exhibited an important reduction of their serial search rates for a conjunction target with contralesional displays. In support of Treisman's feature integration theory, a visual attention deficit leads to a marked impairment in feature integration whereas it does not appear to affect feature encoding.

scholarly journals Early vision and visual attention

Psihologija ◽  
2003 ◽  
Vol 36 (3) ◽  
pp. 241-254
Author(s):  
Vasilije Gvozdenovic
Keyword(s):  
Visual Search ◽  
Visual Perception ◽  
Visual Attention ◽  
Cognitive Processes ◽  
Feature Integration ◽  
Integration Theory ◽  
Early Vision ◽  
Scientific Approach ◽  
Feature Integration Theory

The question whether visual perception is spontaneous, sudden or is running through several phases, mediated by higher cognitive processes, was raised ever since the early work of Gestalt psychologists. In the early 1980s, Treisman proposed the feature integration theory of attention (FIT), based on the findings of neuroscience. Soon after publishing her theory a new scientific approach appeared investigating several visual perception phenomena. The most widely researched were the key constructs of FIT, like types of visual search and the role of the attention. The following review describes the main studies of early vision and visual attention.

scholarly journals Unconscious Familiarity-based Color–Form Binding: Evidence from Visual Extinction

2016 ◽  
Vol 28 (3) ◽  
pp. 501-516 ◽  
Author(s):  
Sarah J. Rappaport ◽  
M. Jane Riddoch ◽  
Magda Chechlacz ◽  
Glyn W. Humphreys
Keyword(s):  
Visual Processing ◽  
Brain Regions ◽  
Good Evidence ◽  
Feature Binding ◽  
Integration Theory ◽  
Major Question ◽  
Visual Extinction ◽  
Feature Integration Theory ◽  
Color Form ◽  
Familiar Stimuli

There is good evidence that early visual processing involves the coding of different features in independent brain regions. A major question, then, is how we see the world in an integrated manner, in which the different features are “bound” together. A standard account of this has been that feature binding depends on attention to the stimulus, which enables only the relevant features to be linked together [Treisman, A., & Gelade, G. A feature-integration theory of attention. Cognitive Psychology, 12, 97–136, 1980]. Here we test this influential idea by examining whether, in patients showing visual extinction, the processing of otherwise unconscious (extinguished) stimuli is modulated by presenting objects in their correct (familiar) color. Correctly colored objects showed reduced extinction when they had a learned color, and this color matched across the ipsi- and contralesional items (red strawberry + red tomato). In contrast, there was no reduction in extinction under the same conditions when the stimuli were colored incorrectly (blue strawberry + blue tomato; Experiment 1). The result was not due to the speeded identification of a correctly colored ipsilesional item, as there was no benefit from having correctly colored objects in different colors (red strawberry + yellow lemon; Experiment 2). There was also no benefit to extinction from presenting the correct colors in the background of each item (Experiment 3). The data suggest that learned color–form binding can reduce extinction even when color is irrelevant for the task. The result is consistent with preattentive binding of color and shape for familiar stimuli.

scholarly journals Visual search of illusory contours: Shape and orientation effects

Psihologija ◽  
2008 ◽  
Vol 41 (1) ◽  
pp. 53-67 ◽  
Author(s):  
Vasilije Gvozdenovic
Keyword(s):  
Visual Search ◽  
Visual Processing ◽  
Experimental Studies ◽  
The Other ◽  
Integration Theory ◽  
Theoretical Interpretation ◽  
Specific Class ◽  
Illusory Contours ◽  
Experimental Procedure ◽  
Feature Integration Theory

Illusory contours are specific class of visual stimuli that represent stimuli configurations perceived as integral irrespective of the fact that they are given in fragmented uncompleted wholes. Due to their specific features, illusory contours gained much attention in last decade representing prototype of stimuli used in investigations focused on binding problem. On the other side, investigations of illusory contours are related to problem of the level of their visual processing. Neurophysiologic studies show that processing of illusory contours proceed relatively early, on the V2 level, on the other hand most of experimental studies claim that illusory contours are perceived with engagement of visual attention, binding their elements to whole percept. This research is focused on two experiments in which visual search of illusory contours are based on shape and orientation. The main experimental procedure evolved the task proposed by Bravo and Nakayama where instead of detection, subjects were performing identification of one among two possible targets. In the first experiment subjects detected the presence of illusory square or illusory triangle, while in the second experiment subject were detecting two different orientations of illusory triangle. The results are interpreted in terms of visual search and feature integration theory. Beside the type of visual search task, search type proved to be dependent of specific features of illusory shapes which further complicate theoretical interpretation of the level of their perception.

scholarly journals Prospects for using visual search tasks in modern cognitive psychology

2020 ◽  
Vol 9 (2) ◽  
pp. 107-116
Author(s):  
E.S. Gorbunova
Keyword(s):  
Cognitive Psychology ◽  
Visual Search ◽  
Visual Attention ◽  
Target Stimulus ◽  
Real Life ◽  
Laboratory Studies ◽  
Search Tasks ◽  
Life Tasks ◽  
Standard Task

The article describes the main results of modern foreign studies with modifications of classical visual search tasks, as well as proposed classification of such modifications. The essence of visual search is to find target stimuli among the distracters, and the standard task involves finding one target stimulus, which is usually a simple object. Modifications to the standard task may include the presence of more than one target on the screen, the search for more than one type of target, and options that combine both of these modifications. Proposed modifications of the standard task allow not only to study new aspects of visual attention, but also to approach real-life tasks within laboratory studies.

scholarly journals Visual Search in 3D: Effects of Monoscopic and Stereoscopic Cues to Depth on the Validity of Feature Integration Theory and Perceptual Load Theory

2021 ◽  
Vol 12 ◽  
Author(s):  
Ciara M. Greene ◽  
John Broughan ◽  
Anthony Hanlon ◽  
Seán Keane ◽  
Sophia Hanrahan ◽  
...  
Keyword(s):  
Perceptual Load ◽  
Three Dimensional ◽  
Feature Integration ◽  
Integration Theory ◽  
Apparent Depth ◽  
Three Dimensional Objects ◽  
Load Theory ◽  
Search Tasks ◽  
Single Feature ◽  
Feature Integration Theory

Previous research has successfully used feature integration theory to operationalise the predictions of Perceptual Load Theory, while simultaneously testing the predictions of both models. Building on this work, we test the extent to which these models hold up in a 3D world. In two experiments, participants responded to a target stimulus within an array of shapes whose apparent depth was manipulated using a combination of monoscopic and stereoscopic cues. The search task was designed to test the predictions of (a) feature integration theory, as the target was identified by a single feature or a conjunction of features and embedded in search arrays of varying size, and (b) perceptual load theory, as the task included congruent and incongruent distractors presented alongside search tasks imposing high or low perceptual load. Findings from both experiments upheld the predictions of feature integration theory, regardless of 2D/3D condition. Longer search times in conditions with a combination of monoscopic and stereoscopic depth cues suggests that binding features into three-dimensional objects requires greater attentional effort. This additional effort should have implications for perceptual load theory, yet our findings did not uphold its predictions; the effect of incongruent distractors did not differ between conjunction search trials (conceptualised as high perceptual load) and feature search trials (low perceptual load). Individual differences in susceptibility to the effects of perceptual load were evident and likely explain the absence of load effects. Overall, our findings suggest that feature integration theory may be useful for predicting attentional performance in a 3D world.

Approaches to Visual Search

2014 ◽  
Author(s):  
Jeremy M. Wolfe
Keyword(s):  
Visual Search ◽  
Visual Awareness ◽  
Integration Theory ◽  
Visual Features ◽  
Feature Integration Theory ◽  
Parallel Feature ◽  
Basic Features ◽  
Relationship Of ◽  
The Relationship ◽  
Original Feature

In her original Feature Integration Theory, Anne Treisman proposed that we process a limited set of basic preattentive, visual features in parallel across the visual field. Binding those features together into coherent, recognizable objects requires selective attention of item after item. In Treisman’s original conception, searches were divided into parallel feature searches and other serial self-terminating searches. Wolfe’s Guided Search model added the idea that the deployment of attention could be guided by preattentive information. In this view, the efficiency of search is related to the effectiveness of guidance on a continuum from perfect guidance, in the case of simple feature pop-out, to no guidance when no basic features distinguish target from distractors. This chapter reviews the evidence for different basic, preattentive features and describes the current understanding of the rules of guidance, the mechanics of visual search, and the relationship of these processes to visual awareness.

Preattentive Binding of Auditory and Visual Stimulus Features

2005 ◽  
Vol 17 (2) ◽  
pp. 320-339 ◽  
Author(s):  
István Winkler ◽  
István Czigler ◽  
Elyse Sussman ◽  
János Horváth ◽  
László Balázs
Keyword(s):  
Time Pressure ◽  
Standard Stimulus ◽  
Event Related Potential ◽  
Feature Binding ◽  
The Other ◽  
Integration Theory ◽  
Visual Modality ◽  
Feature Integration Theory ◽  
Memory Representations ◽  
Stimulus Features

We investigated the role of attention in feature binding in the auditory and the visual modality. One auditory and one visual experiment used the mismatch negativity (MMN and vMMN, respectively) event-related potential to index the memory representations created from stimulus sequences, which were either task-relevant and, therefore, attended or task-irrelevant and ignored. In the latter case, the primary task was a continuous demanding within-modality task. The test sequences were composed of two frequently occurring stimuli, which differed from each other in two stimulus features (standard stimuli) and two infrequently occurring stimuli (deviants), which combined one feature from one standard stimulus with the other feature of the other standard stimulus. Deviant stimuli elicited MMN responses of similar parameters across the different attentional conditions. These results suggest that the memory representations involved in the MMN deviance detection response encoded the frequently occurring feature combinations whether or not the test sequences were attended. A possible alternative to the memory-based interpretation of the visual results, the elicitation of the McCollough color-contingent aftereffect, was ruled out by the results of our third experiment. The current results are compared with those supporting the attentive feature integration theory. We conclude that (1) with comparable stimulus paradigms, similar results have been obtained in the two modalities, (2) there exist preattentive processes of feature binding, however, (3) conjoining features within rich arrays of objects under time pressure and/or long-term retention of the feature-conjoined memory representations may require attentive processes.

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