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 ◽  
...  

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.

Author(s):  
Darryl G. Humphrey ◽  
Arthur F. Kramer ◽  
Donnelle R. Schneider

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.


2018 ◽  
Author(s):  
Shekoofeh Hedayati ◽  
Brad Wyble

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.


Perception ◽  
1992 ◽  
Vol 21 (1) ◽  
pp. 21-38 ◽  
Author(s):  
Marie E Poisson ◽  
Frances Wilkinson

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.


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