Distractor Ratio and Grouping Processes in Visual Conjunction Search

Perception ◽  
1992 ◽  
Vol 21 (1) ◽  
pp. 21-38 ◽  
Author(s):  
Marie E Poisson ◽  
Frances Wilkinson
Keyword(s):  
Search Strategy ◽  
Conjunction Search ◽  
Integration Theory ◽  
Distractor Type ◽  
Fixed Size ◽  
Single Feature ◽  
Search Processes ◽  
Cast Doubt ◽  
Feature Integration Theory

According to feature integration theory, conjunction search is conducted via a serial self-terminating search. However, effects attributed to search processes operating on the entire display may actually reflect search restricted to elements defined by a single feature. In experiment 1 this question is addressed in a reaction-time (RT) paradigm by varying distractor ratios within an array of fixed size. For trials in which the target was present in the array, RT functions were roughly symmetric, the shortest RTs being for extreme distractor ratios, and the longest RTs being for arrays in which there were an equal number of each distractor type. This result is superficially consistent with Zohary and Hochstein's interpretation that subjects search for only one distractor type and are able to switch search strategy from trial to trial. However, negative-trial data from experiment 1 cast doubt on this interpretation. In experiment 2 the possible role of ‘pop out’ and of distractor grouping in visual conjunction search is investigated. Results of experiment 2 suggest that grouping may play a more important role than does distractor ratio, and point to the importance of the spatial layout of the target and of the distractor elements in visual conjunction search. Results of experiment 2 also provide clear evidence that groups of spatially adjacent homogeneous elements may be processed as a unit.

Visual Search and the Older Adult: Not all is Lost

1995 ◽  
Vol 39 (2) ◽  
pp. 134-138
Author(s):  
Darryl G. Humphrey ◽  
Arthur F. Kramer ◽  
Donnelle R. Schneider
Keyword(s):  
Search Task ◽  
Visual Selective Attention ◽  
Feature Integration ◽  
Conjunction Search ◽  
Integration Theory ◽  
Search Tasks ◽  
Age Related ◽  
Feature Conjunction ◽  
Integration Mechanism ◽  
Feature Integration Theory

Plude and Doussard-Roosevelt (1989) reported age-related search slope differences in a conjunction search task but not in a feature search task. According to Feature Integration Theory (Treisman & Gelade, 1980), older adults may suffer an impairment in the feature integration mechanism required for conjunction searches. We extend this work by examining age-related differences a series of feature, conjunction, and triple conjunction search tasks. The results of the feature and conjunction search tasks support the previous findings. However, the results of the triple conjunction search task suggest that the conjunction search impairment is not universal. As the triple conjunction search results are difficult to accommodate within Feature Integration Theory, the results are discussed within the framework of the Guided Search model of visual selective attention.

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.

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 Awareness of visual events without concomitant spatiotopic information

2018 ◽  
Author(s):  
Shekoofeh Hedayati ◽  
Brad Wyble
Keyword(s):  
Receptive Fields ◽  
Spatial Location ◽  
Feature Integration ◽  
Integration Theory ◽  
Complex Objects ◽  
Visual Events ◽  
Complex Stimuli ◽  
Single Feature ◽  
Visual Areas ◽  
Feature Integration Theory

To what extent does spatiotopic location accompany the representation of a visual event? Feature integration theory suggests that identifying a multi-feature object requires focus on its spatial location to integrate those features. Moreover, single unit data from neurons preferring complex objects, indicates that they have retinotopic receptive fields. It can therefore be predicted that identification of complex stimuli is contingent upon localization of their features by attention. To evaluate this, we presented participants with a brief array of characters with instructions to identify and locate the solitary letter. Surprisingly, subjects sometimes identified the target without knowing where it had been presented. However, when targets were marked by a single feature (color), there was no evidence of identifying the target without locating it also. These results indicate that consciously accessible representations of visual events can form despite being untethered to spatially specific neural activity in early visual areas.

Andrew Lang and Scottish Historiography: Taking on Tradition

2015 ◽  
Vol 94 (2) ◽  
pp. 207-236 ◽  
Author(s):  
Catriona M. M. Macdonald
Keyword(s):  
Nineteenth Century ◽  
Sir Walter Scott ◽  
Scientific Methods ◽  
European Context ◽  
The Reformation ◽  
Cast Doubt ◽  
Scottish History ◽  
University Setting ◽  
Andrew Lang

The career and posthumous reputation of Andrew Lang (1844–1912) call into question Scottish historiographical conventions of the era following the death of Sir Walter Scott which foreground the apparent triumph of scientific methods over Romance and the professionalisation of the discipline within a university setting. Taking issue with the premise of notions relating to the Strange Death of Scottish History in the mid-nineteenth century, it is proposed that perceptions of Scottish historiographical exceptionalism in a European context and presumptions of Scottish inferiorism stand in need of re-assessment. By offering alternative readings of the reformation, by uncoupling unionism from whiggism, by reaffirming the role of Romance in ‘serious’ Scottish history, and by disrupting distinctions between whig and Jacobite, the historical works and the surviving personal papers of Andrew Lang cast doubt on many conventional grand narratives and the paradigms conventionally used to make sense of Scottish historiography.

Sports News, Commentary and Interviews, From the Other Side: Journalists Seen Through the Eyes of Athletes

2021 ◽  
pp. 216747952199237
Author(s):  
Ondřej Trunečka
Keyword(s):  
Athletic Performance ◽  
The Other ◽  
Professional Athletes ◽  
Main Role ◽  
Cast Doubt ◽  
The Media ◽  
Sports News

This study explores how professional athletes perceive sports journalists and the role of the media. They acknowledge that communication with journalists is an essential part of their profession and appreciate the verified information, knowledge, and dutiful preparation. They consider the main role of media as monitorial. In some cases, they cast doubt on journalists’ ability to evaluate athletic performance accurately, and they are also critical of errors in interviews, however they acknowledgethat there are good, and possibly excellent journalists as well.

Industrial Policy and Local Economic Transformation: Evidence From the U.S. Rust Belt

2021 ◽  
pp. 089124242110228
Author(s):  
Ben Armstrong
Keyword(s):  
Industrial Policy ◽  
Local Governments ◽  
State Level ◽  
Economic Transformation ◽  
Local Economy ◽  
Rust Belt ◽  
Industrial Policies ◽  
Cast Doubt ◽  
State And Local

State and local governments frequently invest in policies aimed at stimulating the growth of new industries, but studies of industrial policy and related economic development initiatives cast doubt on their effectiveness. This article examines the role of state-level industrial policies in contributing to the different economic trajectories of two U.S. metro areas—Pittsburgh, Pennsylvania, and Cleveland, Ohio—as they adapted to the decline of their legacy industries. Comparative case studies show that industrial policies in Pittsburgh, which empowered research universities as local economic leaders, contributed to the transformation of the local economy. In Cleveland, by contrast, state industrial policies invested in making incremental improvements, particularly in legacy sectors. The article concludes that by empowering new local economic actors—such as universities—industrial policies can foment political change that enables structural economic change to follow.

scholarly journals Reporting of the Role of the Expert Searcher in Cochrane Reviews

2006 ◽  
Vol 1 (4) ◽  
pp. 3 ◽  
Author(s):  
Li Zhang ◽  
Margaret Sampson ◽  
Jessie McGowan
Keyword(s):  
Systematic Reviews ◽  
Search Strategy ◽  
Data Extraction ◽  
Cochrane Library ◽  
Eligibility Criteria ◽  
Statistical Decision ◽  
Cochrane Reviews ◽  
Statistical Decisions ◽  
Search Quality

Introduction - This study applied the principles of evidence based information practice to clarify the role of information specialists and librarians in the preparation of Cochrane systematic reviews and to determine whether information specialists impact the quality of searching in Cochrane systematic reviews. Objectives - This research project sought to determine how the contribution of the person responsible for searching in the preparation of Cochrane systematic reviews was reported; whether the contribution was recognized through authorship or acknowledgement; the qualifications of the searcher; and the association between the type of contributorship and characteristics of the search strategy, assessability, and the presence of certain types of errors. Methods - Data sources: The Cochrane Database of Systematic Reviews, The Cochrane Library 3 (2002). Inclusion criteria: The study included systematic reviews that met the following criteria: one or more sections of the Cochrane Highly Sensitive Search Strategy were utilised, primary studies were either randomised controlled trials (RCTs) or quasi-RCTs, and included and excluded studies were clearly identified. Data extraction: Two librarians assessed the searches for errors, establishing consensus on discordant ratings. Results - Of the 169 reviews screened for this project, 105 met all eligibility criteria. Authors fulfilled the searching role in 41.9% of reviews studied, acknowledged persons or groups in 13.3%, a combination in 9.5%, and the role was not reported in 35.2% of reviews. For the 78 reviews in which meta-analyses were performed, the positions of those responsible for statistical decisions were examined for comparative purposes. The statistical role was performed by an author in 47.4% of cases and unreported in the same number of cases. Insufficient analyzable data was obtained regarding professional qualifications (3/105 for searching, 2/78 for statistical decisions). Search quality was assessed for 66 searches across 74 reviews. In general, it was more possible to assess the search quality when the searcher role was reported. An association was found between the reporting of searcher role and the presence of a consequential error. There was no association between the number of consequential errors and how the contribution of the searcher was reported. Conclusions - Qualifications of the persons responsible for searching and statistical decision-making were poorly reported in Cochrane reviews, but more complete role reporting is associated with greater assessability of searches and fewer substantive errors in search strategies.

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