Visual Search for Size-Defined Target Objects is Modulated by the Ebbinghaus Apparent-Size Illusion: Facilitatory and Inhibitory Effects of the Context Objects

Perception ◽  
10.1068/p5139 ◽  
2006 ◽  
Vol 35 (5) ◽  
pp. 671-700 ◽  
Author(s):  
Hermann J Müller ◽  
Astrid Busch
Keyword(s):  
Visual Search ◽  
Strong Influence ◽  
Apparent Size ◽  
Interference Effects ◽  
Test Context ◽  
Inhibitory Effects ◽  
Ebbinghaus Illusion ◽  
Test Circle ◽  
Colour Contrast

Five experiments were carried out to investigate under which conditions the apparent size of objects is computed and exploited optimally in visual search for size-defined targets. Observers searched for a target test circle that was retinally larger than the distractor test circles, with both types of circles surrounded by context circles modulating the apparent size of the test circles (Ebbinghaus illusion). RTs were the faster the better test circles could be differentiated from the context circles, ie with smaller numbers of context circles, larger distances, and higher lightness (or colour) contrast between test and context circles. Apparent-size modulation had a strong influence on search RTs, resulting in faster RTs with smaller, and slower RTs with larger, context circles. A model assuming overall facilitatory effects of the apparent-size modulation and interference effects arising from decreasing test-context circle discriminability can explain the present results.

scholarly journals Simple action alters attention towards visual features

2021 ◽  
Author(s):  
Zixuan Wang ◽  
Blaire J. Weidler ◽  
Pei Sun ◽  
Richard A. Abrams
Keyword(s):  
Visual Search ◽  
Strong Influence ◽  
Visual Features ◽  
Prime Stimulus ◽  
Action Effect ◽  
Series Of Experiments ◽  
Simple Action ◽  
Prior Action

AbstractRecent studies have revealed anaction effect, in which a simple action towards a prime stimulus biases attention in a subsequent visual search in favor of objects that match the prime. However, to date the majority of research on the phenomenon has studied search elements that are exact matches to the prime, and that vary only on the dimension of color, making it unclear how general the phenomenon is. Here, across a series of experiments, we show that action can also prioritize objects that match the shape of the prime. Additionally, action can prioritize attention to objects that match only one of either the color or the shape of the prime, suggesting that action enhances individual visual features present in the acted-on objects. The pattern of results suggests that the effect may be stronger for color matches – prioritization for shape only occurred when attention was not drawn to the color of the prime, whereas prioritization for color occurred regardless. Taken together, the results reveal that a prior action can exert a strong influence on subsequent attention towards features of the acted-on object.

Attentional Modulation of Size Contrast

1992 ◽  
Vol 45 (4) ◽  
pp. 529-546 ◽  
Author(s):  
Gordon L. Shulman
Keyword(s):  
Vertical Axis ◽  
Horizontal Axis ◽  
Ebbinghaus Illusion ◽  
Attentional Modulation ◽  
Test Circle ◽  
Test Size ◽  
Large Context ◽  
Size Contrast

A test circle surrounded by smaller context circles appears larger if presented in isolation, whereas a test circle surrounded by large context circles is seen as smaller than in isolation. Two experiments are reported indicating that this phenomenon, the Ebbinghaus illusion, depends on whether subjects are attending to the context circles. Subjects first saw a reference circle and then a briefly presented (150 msec) test circle. Their task was to determine whether the test circle was larger or smaller than the reference. The test circle was surrounded by smaller context circles of one colour arrayed along a horizontal axis centred on the test, and larger context circles of a different colour arrayed along a vertical axis centred on the test. Subjects judged both the size of the test and the colours of either the small or large context circles. Perceived test size changed systematically, depending on which context circles were task-relevant.

scholarly journals Some illusions are more inconsistent than others

2019 ◽  
Author(s):  
Jeroen B. J. Smeets ◽  
Eli Brenner
Keyword(s):  
Motion Aftereffect ◽  
Apparent Size ◽  
Ebbinghaus Illusion ◽  
Reach To Grasp ◽  
Grip Aperture ◽  
Maximum Grip Aperture ◽  
Pencil And Paper ◽  
Maximum Grip

Illusions are characterized by inconsistencies. For instance, in the motion aftereffect, we see motion without an equivalent change in position. We used a simple pencil-and-paper experiment to determine whether illusions that influence an object’s apparent size give rise to equivalent changes in apparent positions along the object’s outline. We found different results for two equally strong size illusions. The Ebbinghaus illusion affected perceived positions in a way that was consistent with its influence on perceived size, but a modified diagonal illusion did not affect perceived positions. This difference between the illusions might explain why there are so many conflicting reports about the effects of size illusions on the maximum grip aperture during reach-to-grasp movements.

scholarly journals Reward Value Is More Important Than Physical Saliency During Bumblebee Visual Search For Multiple Rewarding Targets

2020 ◽  
Author(s):  
Vivek Nityananda ◽  
Lars Chittka
Keyword(s):  
Visual Search ◽  
Training Session ◽  
Colour Contrast ◽  
High Reward ◽  
Reward Value ◽  
Current Task ◽  
Flower Choice

AbstractSeveral animals, including bees, use visual search to distinguish targets of interest and ignore distractors. While bee flower choice is well studied, we know relatively little about how they choose between multiple rewarding flowers in complex floral environments. Two important factors that could influence bee visual search for multiple flowers are the physical saliency (colour contrast against the background) of flowers and the reward value associated with them. We here investigated how these two different factors contribute to bee visual search. We trained bees to independently recognize two rewarding colours that in different experiments differed in either physical saliency, reward value or both. We then measured their choices and attention to these colours in the presence of distractors in a test without reinforcement. We found that bees preferred more salient or higher rewarding flowers and ignored distractors. When the high-reward flowers were less salient than the low-reward flowers, bees were nonetheless equally likely to choose high-reward flowers. Bees were more also more likely to attend to these high-reward flowers, with higher inspection times around them and faster search times when choosing them. When flowers differed in reward, we also found an effect of the training order with low-reward targets being more likely to be chosen if they had been encountered during the more immediate training session prior to the test. Our results parallel recent findings from humans demonstrating that reward value can attract attention even when targets are less salient and irrelevant to the current task.

Preattentive Processing of Object Size: Implications for Theories of Size Perception

Perception ◽  
1993 ◽  
Vol 22 (10) ◽  
pp. 1175-1193 ◽  
Author(s):  
Geoffrey W Stuart ◽  
Terence R J Bossomaier ◽  
Sue Johnson
Keyword(s):  
Visual Search ◽  
Size Perception ◽  
Viewing Distance ◽  
Frequency Content ◽  
Interference Effects ◽  
Size Discrimination ◽  
Cross Sectional ◽  
Preattentive Processing ◽  
Cross Sectional Size ◽  
Boundary Curvature

Information about the visual angle size of objects is important for maintaining object constancy with variations in viewing distance. Although human observers are quite accurate at judging spatial separations (or cross-sectional size), they are prone to error when there are other spans nearby, as in classical illusions such as the Müller-Lyer illusion. It is possible to reconcile these aspects of size perception by assuming that the size domain is sampled sparsely. It was shown by means of a visual search procedure that the size of objects is processed preattentively and in parallel across the visual field. It was demonstrated that an object's size, rather than its boundary curvature or spatial-frequency content, provides the basis for parallel visual search. It was also shown that texture borders could be substituted for luminance borders, indicating that object boundaries at the relevant spatial scale provide the input to size perception. Parallel processing imposes a severe computational constraint which provides support for the assumption of sparse sampling. An economical model based on several broadly tuned layers of size detectors is proposed to account for the parallel extraction of size, the Weberian behaviour of size discrimination, and the occurrence of strong interference effects in the size domain.

scholarly journals Different effects of reward value and saliency during bumblebee visual search for multiple rewarding targets

2021 ◽  
Author(s):  
Vivek Nityananda ◽  
Lars Chittka
Keyword(s):  
Visual Search ◽  
Training Session ◽  
Colour Contrast ◽  
High Reward ◽  
Reward Value ◽  
Two Factors ◽  
Current Task ◽  
Flower Choice

AbstractSeveral animals, including bees, use visual search to distinguish targets of interest and ignore distractors. While bee flower choice is well studied, we know relatively little about how they choose between multiple rewarding flowers in complex floral environments. Two factors that could influence bee visual search for multiple flowers are the saliency (colour contrast against the background) and the reward value of flowers. We here investigated how these two different factors contribute to bee visual search. We trained bees to independently recognize two rewarding flower types that, in different experiments, differed in either saliency, reward value or both. We then measured their choices and attention to these flowers in the presence of distractors in a test without reinforcement. We found that bees preferred more salient or higher rewarding flowers and ignored distractors. When the high-reward flowers were less salient than the low-reward flowers, bees were nonetheless equally likely to choose high-reward flowers, for the reward and saliency values we used. Bees were also more likely to attend to these high-reward flowers, spending higher inspection times around them and exhibiting faster search times when choosing them. When flowers differed in reward, we also found an effect of the training order with low-reward targets being more likely to be chosen if they had been encountered during the more immediate training session prior to the test. Our results parallel recent findings from humans demonstrating that reward value can attract attention even when targets are less salient and irrelevant to the current task.

scholarly journals Three-Quarter Views of Depth-Rotated Faces Induce Face-Specific Capacity Limits in Visual Search

2018 ◽  
Vol 65 (6) ◽  
pp. 360-369
Author(s):  
Volker Thoma ◽  
Jan W. De Fockert
Keyword(s):  
Visual Search ◽  
Specific Capacity ◽  
High Load ◽  
Target Face ◽  
Gaze Direction ◽  
Interference Effects ◽  
Capacity Limits ◽  
Capacity Limitations ◽  
Famous Person ◽  
Low Load

Abstract. Participants made speeded categorization decisions regarding a famous person (politician or film star) accompanied by a peripheral distracter face (either the same or from the opposite category). The first experiment found that processing a peripheral distracter face is independent of load when the search set contains name strings. The search set in the second experiment consisted of faces. Interference effects between the target and distracter face (both shown in frontal views) were found when no additional non-target faces were present (low load), but not when two non-famous faces (high load) accompanied the target face, even when the latter were shown in three-quarter views. These results indicate that face-specific capacity limitations are independent of changes in view (up to 45°) and gaze direction.

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