Characteristics of perceptual grouping in rats.

Kurylo, Daniel D.; Nest, Jessica Van; Knepper, Bryan

doi:10.1037/0735-7036.111.2.126

Cited by 23 publications

(26 citation statements)

References 36 publications

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“…Comparative investigations therefore suggest human/nonhuman primate differences in global precedence and a reduced proficiency for proximity grouping. A reduced sensitivity to grouping cues has also been reported in other nonhuman species, such as rats (Kurylo, Van Nest, & Knepper, 1997;Kurylo, 2008) and Australian sea lions (Burke, Everingham, Rogers, Hinton, & Hall-Aspland, 2001) in tasks featuring bistable arrays of dots.…”

mentioning

confidence: 62%

Processing of contour closure by baboons (Papio papio).

Barbet¹,

Fagot²

2011

Journal of Experimental Psychology: Animal Behavior Processes

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This study investigated the Gestalt law of closure in baboons. Using a computer-controlled self-testing procedure, we trained baboons (Papio papio) to discriminate open versus closed shapes presented on a touch screen with a two-alternative forced choice procedure. Ten baboons (OPEN + group) were trained with the open shapes serving as the positive stimulus (S+), and nine others (CLOSE + group) were trained with the closed shape serving as S+. The OPEN + group obtained higher discrimination performance than the CLOSE + group (Exp 1), but its scores declined when new line segments were added to the stimuli (Exp 2) and after smoothing the end points of the open shapes (Exp 3). The CLOSE + group was less affected by the above manipulations of local stimulus dimension, but its performance was disrupted when the collinearity end points was reduced (Exp 3). Use of a visual search task revealed that the search for an open shape among closed distractors was less attention demanding in baboons than the search for a closed shape among open ones (Exp 4). It is concluded that (1) end lines rather than closeness per se are perceptual primitives for the open versus closed discrimination in baboons, and (2) the relative emphasis on local or configural cues when processing contour closure depends on experiential factors in baboons and is thus subject to interindividual variations.

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mentioning

confidence: 62%

Processing of contour closure by baboons (Papio papio).

Barbet¹,

Fagot²

2011

Journal of Experimental Psychology: Animal Behavior Processes

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“…Kurylo et al (1997) found that rats trained to discriminate horizontal from vertical solid luminance-defined lines did not readily transfer to arrays of similar orientations that consisted of disjoint elements (dots) varying in proximity and alignment. Specifically, Kurylo et al (1997) found that proximity was used as a cue for perceptual grouping; however, its effectiveness was diminished relative to humans. Moreover, alignment was not used by rats as a grouping cue when tested in isolation.…”

Section: Can Rats Perceive Shapes Holistically?mentioning

confidence: 96%

“…First, it is worth recalling that rats have quite poor visual acuity compared with humans, and see as well at 1 m as we see at 10 m. Thus, shapes that appear quite clear to us would seem blurred to a rat (see http://www.ratbehavior.org/RatVision.htm for an excellent illustration of this). Second, rats have been found to have a diminished capacity, relative to humans, to use proximity and alignment cues for perceptual grouping (Kurylo et al 1997). Kurylo et al (1997) found that rats trained to discriminate horizontal from vertical solid luminance-defined lines did not readily transfer to arrays of similar orientations that consisted of disjoint elements (dots) varying in proximity and alignment.…”

Section: Can Rats Perceive Shapes Holistically?mentioning

confidence: 99%

“…Second, rats have been found to have a diminished capacity, relative to humans, to use proximity and alignment cues for perceptual grouping (Kurylo et al 1997). Kurylo et al (1997) found that rats trained to discriminate horizontal from vertical solid luminance-defined lines did not readily transfer to arrays of similar orientations that consisted of disjoint elements (dots) varying in proximity and alignment. Specifically, Kurylo et al (1997) found that proximity was used as a cue for perceptual grouping; however, its effectiveness was diminished relative to humans.…”

Section: Can Rats Perceive Shapes Holistically?mentioning

confidence: 99%

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Do rats use shape to solve “shape discriminations”?

Minini¹,

Jeffery²

2006

Learn. Mem.

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Visual discrimination tasks are increasingly used to explore the neurobiology of vision in rodents, but it remains unclear how the animals solve these tasks: Do they process shapes holistically, or by using low-level features such as luminance and angle acuity? In the present study we found that when discriminating triangles from squares, rats did not use shape but instead relied on local luminance differences in the lower hemifield. A second experiment prevented this strategy by using stimuli-squares and rectangles-that varied in size and location, and for which the only constant predictor of reward was aspect ratio (ratio of height to width: a simple descriptor of "shape"). Rats eventually learned to use aspect ratio but only when no other discriminand was available, and performance remained very poor even at asymptote. These results suggest that although rats can process both dimensions simultaneously, they do not naturally solve shape discrimination tasks this way. This may reflect either a failure to visually process global shape information or a failure to discover shape as the discriminative stimulus in a simultaneous discrimination. Either way, our results suggest that simultaneous shape discrimination is not a good task for studies of visual perception in rodents.Discrimination tasks have long been used to probe perceptual processes in animals, and visual discrimination tasks, particularly automated ones, are increasingly used in rodents because of the contribution that rodent neurobiological studies (such as newly emerging transgenic models) can make to understanding the brain mechanisms underlying visual perception (Bussey et al. 1994(Bussey et al. , 2001Cook et al. 2004). Visual discrimination tasks often require the animals to choose between simple geometric shapes, and an implicit assumption in these studies is that rats and mice process shape in a holistic manner when making these discriminations. This assumption, however, has never been properly verified, and rests mainly on a relatively old literature (Fields 1932;Lashley 1938; Sutherland 1961a,b). Discovering the perceptual and cognitive processes underlying these kinds of behavioral tasks is critical if we are to make appropriate links with emerging neurobiological discoveries.The present paper reports a series of investigations that led us to try and determine whether rats really use "shape" when making shape discriminations. Believing at the outset that this was a well-secured fact, we began with a more ambitious experiment to determine whether rats could respond to figures defined by illusory contours (the so-called "Kanizsa figures"), in which illusory form is created by means of "inducing stimuli" (Fig. 1) and is perceived in the absence of real (i.e., luminance-defined) contours. Several authors have proposed that the perception of illusory figures is largely the result of low-level mechanisms that have evolved to extract contours that are present in the environment but absent from the retinal representation: due, for instance, to occlus...

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“…An orientationselective neuron in visual cortex that is able to process second-order edges would be able to perform the relevant computation to solve this task. The question remains whether the rats integrate information across multiple elements of stimuli when dealing with secondorder edges, as has been shown before for luminancedefined stimuli (Dodwell et al, 1970;Kurylo, Van Nest, & Knepper, 1997; for a review see Zoccolan, 2015).…”

Section: Processing In the Absence Of Local Cuesmentioning

confidence: 92%

Cue-invariant shape recognition in rats as tested with second-order contours

et al. 2015

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Nonhuman primates are the main animal model to investigate high-level properties of human cortical vision. For one property, transformation-invariant object recognition, recent studies have revealed interesting and unknown capabilities in rats. Here we report on the ability of rats to rely upon second-order cues that are important to structure the incoming visual images into figure and background. Rats performed a visual shape discrimination task in which the shapes were not only defined by first-order luminance information but also by a variety of second-order cues such as a change in texture properties. Once the rats were acquainted with a first set of second-order stimuli, they showed a surprising degree of generalization towards new second-order stimuli. The limits of these capabilities were tested in various ways, and the ability to extract the shapes broke down only in extreme cases where no local cues were available to solve the task. These results demonstrate how rats are able to make choices based on fairly complex strategies when necessary.

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Characteristics of perceptual grouping in rats.

Cited by 23 publications

References 36 publications

Processing of contour closure by baboons (Papio papio).

Processing of contour closure by baboons (Papio papio).

Do rats use shape to solve “shape discriminations”?

Cue-invariant shape recognition in rats as tested with second-order contours

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