The Role of Edges in Object Recognition by Pigeons

Perception ◽  
10.1068/p5427 ◽  
2005 ◽  
Vol 34 (11) ◽  
pp. 1353-1374 ◽  
Author(s):  
Jessie J Peissig ◽  
Michael E Young ◽  
Edward A Wasserman ◽  
Irving Biederman

In three experiments, we explored how pigeons use edges, corresponding to orientation and depth discontinuities, in visual recognition tasks. In experiment 1, we compared the pigeon's ability to recognize line drawings of four different geons when trained with shaded images. The birds were trained with either a single view or five different views of each object. Because the five training views had markedly different appearances and locations of shaded surfaces, reflectance edges, etc, the pigeons might have been expected to rely more on the orientation and depth discontinuities that were preserved over rotation and in the line drawings. In neither condition, however, was there any transfer from the rendered images to the outline drawings. In experiment 2, some pigeons were trained with line drawings and shaded images of the same objects associated with the same response (consistent condition), whereas other pigeons were trained with a line drawing and a shaded image of two different objects associated with the same response (inconsistent condition). If the pigeons perceived any correspondence between the stimulus types, then birds in the consistent condition should have learned the discrimination more quickly than birds in the inconsistent condition. But, there was no difference in performance between birds in the consistent and inconsistent conditions. In experiment 3, we explored pigeons' processing of edges by comparing their discrimination of shaded images or line drawings of four objects. Once trained, the pigeons were tested with planar rotations of those objects. The pigeons exhibited different patterns of generalization depending on whether they were trained with line drawings or shaded images. The results of these three experiments suggest that pigeons may place greater importance on surface features indicating materials, such as food or water. Such substances do not have definite boundaries—cued by edges—which are thought to be central to human recognition.

Perception ◽  
10.1068/p3421 ◽  
2002 ◽  
Vol 31 (11) ◽  
pp. 1289-1298 ◽  
Author(s):  
Hidemichi Mitsumatsu ◽  
Kazuhiko Yokosawa

Object recognition becomes difficult when the main axis of the object is foreshortened. It has previously been reported that this so-called foreshortened disadvantage is larger when the silhouette of the object is presented than when the line drawing of the object is presented. The pronounced foreshortened disadvantage in silhouette recognition indicates that the internal details of the object, which are absent in the silhouette, provide useful information, particularly when the main axis is foreshortened. But the role of these internal details remains controversial. One account for the pronounced disadvantage is that the internal details contribute to the derivation of the main axis. The other account is that internal details provide the distinctive features that are directly matched to the object represented in memory. The aim in the present study was to determine which of these two explanations best accounts for the differential foreshortened disadvantage between line drawings and silhouettes. To reduce the uncertainty regarding the axis orientation, a 3-D arrow indicating the orientation of the main axis was presented as a cue before the object itself was presented. As a result, the difference in the foreshortened disadvantage between silhouettes and line drawings disappeared. This indicated that the pronounced foreshortened disadvantage for silhouettes was caused by a lack of axis information. In other words, the internal details provided the information necessary for axis derivation when the axis was foreshortened.


Perception ◽  
1994 ◽  
Vol 23 (1) ◽  
pp. 75-93 ◽  
Author(s):  
Philip J Benson ◽  
David I Perrett

Three experiments are reported in which the role of facial distinctiveness in line-drawing representations of famous faces has been examined. In the first subjects were asked to select their impressions of best likeness interactively from a continuous range of drawings generated in real-time. On average, 42% of caricatures were considered to be the best likeness of famous individuals. The distinctiveness of the target faces related by independent observers correlated with the degree of exaggeration faces received to produce an optimal likeness. More distinctive faces required less caricaturing. In the second experiment caricature levels chosen as best likenesses were investigated. Caricatures of famous faces were recognised more quickly (by 36% of subjects) and more accurately (by 28%) than the true veridical drawings. Thus caricature enhancement can improve recognition in terms of both speed and accuracy. In the third experiment the role of distinctiveness and its interaction with external and internal facial features was investigated. The external (outer) hairline present in the previous experiment was found to provide a powerful frame of reference for the perceptual assessment of individuals' appearances; estimations of best likeness without external features present were, on average, veridical. It is concluded that accurate line drawings of even highly familiar faces are poor at conveying identity. Distinctiveness enhancement improves their likeness and their recognisability. Such caricatured drawings provide improved access to memories of famous faces, which lends strong support to models of human-face memory and processing based on norm-based coding. When required to decide upon the veracity of line drawings based only upon internal features subjects were able to make accurate judgments of veridicality. As well as validating the interaction approach to best-likeness judgments, this result further indicates the difficulty in making judgments of identification based on piecemeal and sparse configural information.


Perception ◽  
10.1068/p6161 ◽  
2009 ◽  
Vol 38 (4) ◽  
pp. 533-551 ◽  
Author(s):  
Ryosuke Niimi ◽  
Kazuhiko Yokosawa

Visual recognition of three-dimensional (3-D) objects is relatively impaired for some particular views, called accidental views. For most familiar objects, the front and top views are considered to be accidental views. Previous studies have shown that foreshortening of the axes of elongation of objects in these views impairs recognition, but the influence of other possible factors is largely unknown. Using familiar objects without a salient axis of elongation, we found that a foreshortened symmetry plane of the object and low familiarity of the viewpoint accounted for the relatively worse recognition for front views and top views, independently of the effect of a foreshortened axis of elongation. We found no evidence that foreshortened front–back axes impaired recognition in front views. These results suggest that the viewpoint dependence of familiar object recognition is not a unitary phenomenon. The possible role of symmetry (either 2-D or 3-D) in familiar object recognition is also discussed.


Perception ◽  
2021 ◽  
Vol 50 (3) ◽  
pp. 266-275
Author(s):  
Aaron Hertzmann
Keyword(s):  

It has often been conjectured that the effectiveness of line drawings can be explained by the similarity of edge images to line drawings. This article presents several problems with explaining line drawing perception in terms of edges, and how the recently proposed Realism Hypothesis resolves these problems. There is nonetheless existing evidence that edges are often the best features for predicting where people draw lines; this article describes how the Realism Hypothesis can explain this evidence.


1978 ◽  
Vol 22 (1) ◽  
pp. 378-382 ◽  
Author(s):  
Richard C. Teitelbaum ◽  
Robert J. Mezzanotte ◽  
Irving Biederman

Subjects performed a task which allowed measurement of their speed of comprehension of real-world scenes: They attempted to detect the incongruity in the relationship between an object and its context. In 100 msec, presentations of line drawings of real-world scenes, objects could be inappropriately positioned (e.g., a fire hydrant on top of a mailbox), sized (e.g., the hydrant looking larger than a truck) or floating in air. Detection times were not significantly affected by priming the subject with a verbal label of the scene prior to its viewing (e.g., telling him he was going to see a “kitchen”) but were significantly affected by the prior presentation of the scene upwards of 30 trials earlier. The results document a remarkably efficient, content addressable, accessing mechanism for visual recognition in humans.


2020 ◽  
Author(s):  
Bahareh Jozranjbar ◽  
Arni Kristjansson ◽  
Heida Maria Sigurdardottir

While dyslexia is typically described as a phonological deficit, recent evidence suggests that ventral stream regions, important for visual categorization and object recognition, are hypoactive in dyslexic readers who might accordingly show visual recognition deficits. By manipulating featural and configural information of faces and houses, we investigated whether dyslexic readers are disadvantaged at recognizing certain object classes or utilizing particular visual processing mechanisms. Dyslexic readers found it harder to recognize objects (houses), suggesting that visual problems in dyslexia are not completely domain-specific. Mean accuracy for faces was equivalent in the two groups, compatible with domain-specificity in face processing. While face recognition abilities correlated with reading ability, lower house accuracy was nonetheless related to reading difficulties even when accuracy for faces was kept constant, suggesting a specific relationship between visual word recognition and the recognition of non-face objects. Representational similarity analyses (RSA) revealed that featural and configural processes were clearly separable in typical readers, while dyslexic readers appeared to rely on a single process. This occurred for both faces and houses and was not restricted to particular visual categories. We speculate that reading deficits in some dyslexic readers reflect their reliance on a single process for object recognition.


Author(s):  
Ya.O. Yemchenko ◽  
K.Ye. Ishcheikin ◽  
I.P. Kaidashev

Psoriasis is one of the most common chronic recurrent systemic autoimmune multifactorial diseases, affected the skin, joints, internal organs and systems of the body. Despite the significant prevalence of psoriasis and a large number of studies devoted this problem there is still no single view on the pathogenesis of this dermatosis. To clear up the pathogenesis of psoriasis, it seems to be reasonable to focus on the common comorbidities or multimorbidities, which may occur in the course of psoriasis, as this issue is still insufficiently studied. Recent reports have proven the evidences of indisputable link between psoriasis and obesity. The scientific literature extensively covers the issues of identical pathogenetic mechanisms of inflammatory processes in psoriasis and obesity. Given the current data on the role of systemic inflammation underlying the development of both psoriasis and obesity, the study of molecular mechanisms of its development and in particularly the role of proinflammatory nuclear transcription factors, thiazolidinediones have been found out as pathogenetically justified medicine of choice for the therapy of these diseases. In this study, we determined the effectiveness of using 30 mg of pioglitazone daily for 6 months in the course of treatment for patients with extensive psoriasis vulgaris of moderate severity, who were also diagnosed as having concomitant grade І-ІІ alimentary obesity that was supported by clinical and immunological findings evidenced of systemic inflammation. Analyzing the results obtained, we have found out the prolonged therapy with pioglitazone leads to a decrease in systemic inflammation and contributes to a milder recurrent course of psoriasis.


Sign in / Sign up

Export Citation Format

Share Document