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 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.

Search Differences for the Presence and Absence of Features in Sustained Attention

1997 ◽  
Vol 41 (2) ◽  
pp. 1288-1292 ◽  
Author(s):  
Victoria S. Schoenfeld ◽  
Mark W. Scerbo
Keyword(s):  
Sustained Attention ◽  
Display Size ◽  
Stimulus Display ◽  
The Other ◽  
Feature Integration ◽  
Integration Theory ◽  
Critical Signal ◽  
Other Hand ◽  
Feature Integration Theory ◽  
Stimulus Features

The present study examined the ability of individuals to look for the presence or absence of stimulus features in a vigilance paradigm. Forty participants monitored a computer display comprised of either 2 or 5 circles for 40 min. Half of the participants were instructed to respond when a line was present in one of the circles, and the other half responded when the line was absent from one of the circles. Although performance declined throughout the vigil in all conditions, the overall level of performance was dependent upon both display size and type of signal. Specifically, performance was worse when searching for the absence as opposed to the presence of the feature, and this effect was exacerbated with the five-stimulus display. On the other hand, display size had no effect when searching for the presence of the feature. These results are discussed with respect to the feature integration theory and the nature of the critical signal in vigilance.

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.

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 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.

Effects of Attachment Styles on the Experience of Equity in Heterosexual Couples Relationships

2003 ◽  
Vol 50 (4) ◽  
pp. 298-310 ◽  
Author(s):  
Ina Grau ◽  
Jörg Doll
Keyword(s):  
Attachment Theory ◽  
Attachment Style ◽  
Intimate Relationships ◽  
Attachment Styles ◽  
Experimental Studies ◽  
The Other ◽  
Heterosexual Couples ◽  
Secure Attachment ◽  
Dependent Variables ◽  
Equity Ratio

Abstract. Employing one correlational and two experimental studies, this paper examines the influence of attachment styles (secure, anxious, avoidant) on a person’s experience of equity in intimate relationships. While one experimental study employed a priming technique to stimulate the different attachment styles, the other involved vignettes describing fictitious characters with typical attachment styles. As the specific hypotheses about the single equity components have been developed on the basis of the attachment theory, the equity ratio itself and the four equity components (own outcome, own input, partner’s outcome, partner’s input) are analyzed as dependent variables. While partners with a secure attachment style tend to describe their relationship as equitable (i.e., they give and take extensively), partners who feel anxious about their relationship generally see themselves as being in an inequitable, disadvantaged position (i.e., they receive little from their partner). The hypothesis that avoidant partners would feel advantaged as they were less committed was only supported by the correlational study. Against expectations, the results of both experiments indicate that avoidant partners generally see themselves (or see avoidant vignettes) as being treated equitably, but that there is less emotional exchange than is the case with secure partners. Avoidant partners give and take less than secure ones.

Computational and experimental studies of the strength of full-scale samples of pipes with defects "metal loss" and "dent with groove"

2020 ◽  
Vol 10 (3) ◽  
pp. 226-233
Author(s):  
Dmitry A. Neganov ◽  
◽  
Victor M. Varshitsky ◽  
Andrey A. Belkin ◽  
◽  
...  
Keyword(s):  
Internal Pressure ◽  
Experimental Studies ◽  
Full Scale ◽  
The Other ◽  
Metal Loss ◽  
Calculation Methods ◽  
Reliable Operation ◽  
Sufficient Stability ◽  
Comparative Results ◽  
The Moment

The article contains the comparative results of the experimental and calculated research of the strength of a pipeline with such defects as “metal loss” and “dent with groove”. Two coils with diameter of 820 mm and the thickness of 9 mm of 19G steel were used for full-scale pipe sample production. One of the coils was intentionally damaged by machining, which resulted in “metal loss” defect, the other one was dented (by press machine) and got groove mark (by chisel). The testing of pipe samples was performed by applying static internal pressure to the moment of collapse. The calculation of deterioration pressure was carried out with the use of national and foreign methodical approaches. The calculated values of collapsing pressure for the pipe with loss of metal mainly coincided with the calculation experiment results based on Russian method and ASME B31G. In case of pipe with dent and groove the calculated value of collapsing pressure demonstrated greater coincidence with Russian method and to a lesser extent with API 579/ASME FFS-1. In whole, all calculation methods demonstrate sufficient stability of results, which provides reliable operation of pipelines with defects.

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