Gideon Caplovitz

Gideon Caplovitz
University of Nevada, Reno | UNR · Department of Psychology

M.S., Ph.D

About

128
Publications
12,359
Reads
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623
Citations
Additional affiliations
August 2010 - present
University of Nevada, Reno
July 2008 - July 2010
August 2003 - June 2008
Dartmouth College
Position
  • PhD Student

Publications

Publications (128)
Preprint
There appear to be three independent systems for allocating attention: space-based, feature based, and object-based. Here, we review the literature of object-based attention to determine its underlying mechanisms. First, findings from unconscious priming and cuing suggest that the pre-attentive targets of object-based attention can be fully develop...
Article
Visual object perception involves neural processes that unfold over time and recruit multiple regions of the brain. Here, we use high-density electroencephalography (EEG) to investigate the spatiotemporal representations of object categories across the dorsal and ventral pathways. In Experiment 1, human participants were presented with images from...
Article
Full-text available
To accomplish the deceptively simple task of perceiving the size of objects in the visual scene, the visual system combines information about the retinal size of the object with several other cues, including perceived distance, relative size, and prior knowledge. When local component elements are perceptually grouped to form objects, the task is fu...
Article
Full-text available
Retinal painting, anorthoscopic perception and amodal completion are terms to describe visual phenomena that highlight the spatiotemporal integrative mechanisms that underlie primate vision. Although commonly studied using simplified lab-friendly stimuli presented on a computer screen, this is a report of observations made in a novel real-world con...
Article
Full-text available
Have you ever searched the pages of a Where’s Waldo ® book and found it difficult to find him? Your eyes jump around the page scanning for his red-and-white striped shirt, but all you seem to find are other funny characters. Maybe you keep getting distracted by a big green monster that does not look anything like Waldo. After you finally find him,...
Article
Theoretical accounts and preliminary evidence suggest that Mindfulness-Based Interventions (MBIs) improve cognitive function, but reviews of empirical studies have provided mixed results. To clarify empirical evidence, we conducted a meta-analysis of 25 studies (n = 1439) and examined the effects of MBIs on four cognitive domains: attention, workin...
Article
Full-text available
When a part of an object is cued, targets presented in other locations on the same object are detected more rapidly and accurately than are targets on other objects. Often in object-based attention experiments, cues and targets appear not only on the same object but also on the same surface. In four psychophysical experiments, we examined whether t...
Article
Full-text available
We recently showed that motion dynamics greatly enhance the magnitude of certain size contrast illusions, such as the Ebbinghaus and Delboeuf illusions. Here, we extend our study of the effect of motion dynamics on size illusions through a novel dynamic corridor illusion, in which a single target translates along a corridor background. Across three...
Article
Full-text available
Understanding of the visual system can be informed by examining errors in perception. We present a novel illusion—Wandering Circles—in which stationary circles undergoing contrast-polarity reversals (i.e., flicker), when viewed peripherally, appear to move about in a random fashion. In two psychophysical experiments, participants rated the strength...
Preprint
Our understanding of the visual system can be informed by examining errors in perception. In this vein, we present a novel illusion that we call the Wandering Circles in which stationary circles undergoing contrast polarity reversals (i.e., flicker), when viewed peripherally, appear to move about in a random fashion. Here we report the results of t...
Article
Full-text available
The motion-induced contour (MIC) was first described by Victor Klymenko and Naomi Weisstein in a series of papers in the 1980s. The effect is created by rotating the outline of a tilted cube in depth. When one of the vertical edges is removed, an illusory contour can be seen in its place. In four experiments, we explored which stimulus features inf...
Article
Full-text available
Although object-related areas were discovered in human parietal cortex a decade ago, surprisingly little is known about the nature and purpose of these representations, and how they differ from those in the ventral processing stream. In this article, we review evidence for the unique contribution of object areas of dorsal cortex to three-dimensiona...
Article
Why are some visual stimuli remembered, whereas others are forgotten? A limitation of recognition paradigms is that they measure aggregate behavioral performance and/or neural responses to all stimuli presented in a visual working memory (VWM) array. To address this limitation, we paired an electroencephalography (EEG) frequency-tagging technique w...
Chapter
When an object partially or completely disappears behind an occluding surface, a representation of that object persists. For example, fragments of no longer visible objects can serve as an input into mid-level constructive visual processes, interacting and integrating with currently visible portions to form perceptual units and global motion signal...
Article
Full-text available
We happened to observe that text that was reflected about either the horizontal or vertical axis was more difficult to read than text that was reflected about first one and then the other, which amounts to a 180-degree rotation. In this article, we review a number of studies that examine the nature of recognizing reflected and inverted letters, and...
Article
Full-text available
The ability to encode, store, and retrieve visually presented objects is referred to as visual working memory (VWM). Although crucial for many cognitive processes, previous research reveals that VWM strictly capacity limited. This capacity limitation is behaviorally observable in the set size effect: the ability to successfully report items in VWM...
Article
Full-text available
During dynamic occlusion, an object passes behind an occluding surface and then later reappears. Even when completely occluded from view, such objects are experienced as continuing to exist or persist behind the occluder, even though they are no longer visible. The contents and neural basis of this persistent representation remain poorly understood...
Article
During apparent motion (AM), an object appears to move smoothly between several locations despite being physically present only intermittently. It has been shown that AM can modulate neural activity within regions of motion-sensitive cortex (hMT+) and primary visual cortex (V1) that represent non-stimulated regions of space along the AM path. Howev...
Article
We introduce a novel illusion – the Bendy Bars illusion, in which stationary bars (i.e. a vertical sinewave grating) appear to bend when dynamically occluded by translating Gaussian ovals. This effect, however, only becomes visible once specific parameters have been met: The illusion is strongest when there are multiple vertically elongated ovals d...
Article
A static Gabor patch containing a drifting sinusoidal grating appears to be displaced in the direction of the carrier motion. We introduce a novel 'rotating square' illusion in which drifting Gabor elements positioned to form a square, together give rise to a global rotational motion percept. This is accomplished by selecting the drift speed of eac...
Article
Full-text available
When an object moves behind a bush, for example, its visible fragments are revealed at different times and locations across the visual field. Nonetheless, a whole moving object is perceived. Unlike traditional modal and amodal completion mechanisms known to support spatial form integration when all parts of a stimulus are simultaneously visible, re...
Conference Paper
Spatiotemporal objects are those whose parts become visible only gradually through motion and dis-occlusion, and must be integrated to form perceptual units. Rather than representational invariance, the perception of spatiotemporal objects requires precise positional and velocity information about fragments in order to accurately align them across...
Poster
It is well established that visual working memory is capacity limited with retrieval performance declining as set size increases. The vast majority of studies investigating working memory capacity have focused on the maintenance phase of working memory tasks. In a recent study we found that neural resources allocated to individual items during enco...
Conference Paper
In recent years a number of exciting fMRI studies have highlighted the role of primary visual cortex in the representation of the perceived size of objects. Several studies have now demonstrated that an object's perceived size, independent of its retinal size, is correlated with functional and anatomical aspects of V1. These results have been surpr...
Poster
It is well established that Visual Working Memory is capacity limited. Recent behavioral research has demonstrated that perceptual grouping can facilitate the retrieval of items stored in working memory. At what stage and by what mechanism are these grouping effects manifesting? In order to answer this question we used high-density electroencephalo...
Article
Full-text available
Objects in the world often are occluded and in motion. The visible fragments of such objects are revealed at different times and locations in space. To form coherent representations of the surfaces of these objects, the visual system must integrate local form information over space and time. We introduce a new illusion in which a rigidly rotating s...
Article
Full-text available
Curvature is a highly informative visual cue for shape perception and object recognition. We introduce a novel illusion-the Lemon Illusion-in which subtle illusory curvature is perceived along contour regions that are devoid of physical curvature. We offer several perceptual demonstrations and observations that lead us to conclude that the Lemon Il...
Article
Full-text available
The Ebbinghaus illusion is a classic example of the influence of a contextual surround on the perceived size of an object. Here, we introduce a novel variant of this illusion called the Dynamic Ebbinghaus illusion in which the size and eccentricity of the surrounding inducers modulates dynamically over time. Under these conditions, the size of the...
Article
Full-text available
The binding problem is a longstanding issue in vision science: i.e., how are humans able to maintain a relatively stable representation of objects and features even though the visual system processes many aspects of the world separately and in parallel? We previously investigated this issue with a variant of the bounce-pass paradigm, which consist...
Article
Full-text available
We present a novel size-contrast illusion that depends on the dynamic nature of the stimulus. In the dynamic illusory size-contrast (DISC) effect, the viewer perceives the size of a target bar to be shrinking when it is surrounded by an expanding box and when there are additional dynamic cues such as eye movements, changes in retinal eccentricity o...
Conference Paper
Background: Spatiotemporal boundary formation (SBF) is the perception of contours, global form, and global motion from discrete transformations of sparse textural elements of which gradual accretion and deletion of texture is a special case (Shipley & Kellman, 1994, 1997). While some aspects of SBF are understood, little work has been done to uncov...
Conference Paper
Many visual attributes appear to be encoded by a norm-based code in which the stimulus is represented by how it deviates from an average or neutral value (the norm). One prediction of these codes is that neural responses should be weaker for stimuli near the norm and stronger for uncharacteristic stimuli, a pattern that has been shown for a variety...
Conference Paper
It has been consistently demonstrated that human observers are able to extract statistical averages from groups of objects in a variety of different feature domains, including but not limited to orientation, color, size, and facial expression. However, little known about how this summary information is used and what function it may serve. Here, we...
Conference Paper
Here we present an original illusion in which polarity reversing, stationary Craik-O'Brien-Cornsweet stimuli viewed under maintained fixation appear to move with dramatic unpredictable trajectories. Some stimulus configurations can lead to significant distortions of shape. For example, in addition to appearing to wander across the screen, a polarit...
Article
A recent study showed that color synesthetes have increased color sensitivity but impaired motion perception. This is exciting because little research has examined how synesthesia affects basic perceptual processes outside the context of synesthetic experiences. The results suggest that synesthesia broadly impacts perception with greater neural imp...
Article
Full-text available
The percept of four rotating dot pairs is bistable. The "local percept" is of four pairs of dots rotating independently. The "global percept" is of two large squares translating over one another (Anstis & Kim 2011). We have previously demonstrated (Kohler, Caplovitz, & Tse 2009) that the global percept appears to move more slowly than the local per...
Conference Paper
Full-text available
To perceive moving objects, the visual system must integrate form and motion information across space and time. Form and motion perception have historically been considered independent processes, but research repeatedly demonstrates that these processes interact in many complex ways. Spatiotemporal form integration (SFI) describes the process by wh...
Conference Paper
The perception of objects in the world depends upon the successful integration of form and motion into a unified neural representation and has traditionally been thought to occur through separate pathways. However, it has recently been shown that that these processes may interact in complex ways. The perceived global shape of an object is dictated...
Conference Paper
In their 2007 paper, Kanai, Sheth, and Shimojo demonstrated that observers were less sensitive to transient changes in moving objects if these changes occurred after the object had been in motion for >300ms. They posited that this was due to a shift from processing motion as individual frames to a gestalt percept. They further proposed a model in w...
Conference Paper
In recent years a number of papers have investigated mechanisms of ‘perceptual grouping’ using illusory figures, specifically Kanizsa figures, as stimuli. Here we take an historical perspective on the use and meaning of the term ‘perceptual grouping’ and contrast it with the use and meaning of other similar terms such as perceptual organization, vi...
Article
Full-text available
As an object rotates, each location on the object moves with an instantaneous linear velocity, dependent upon its distance from the center of rotation, whereas the object as a whole rotates with a fixed angular velocity. Does the perceived rotational speed of an object correspond to its angular velocity, linear velocities, or some combination of th...
Conference Paper
Full-text available
Background / Purpose: Spatiotemporal form integration (SFI) describes the process by which the visual system is able to integrate shape information over space and time to form percepts of stationary and moving objects. Illusory figures revealed by sequentially presented inducers are an excellent example of this integration process. It remains unk...
Article
Full-text available
Our perception of an object's size arises from the integration of multiple sources of visual information including retinal size, perceived distance and its size relative to other objects in the visual field. This constructive process is revealed through a number of classic size illusions such as the Delboeuf Illusion, the Ebbinghaus Illusion and ot...
Article
Full-text available
Our perception of an object’s size arises from the integration of multiple sources of visual information including retinal size, perceived distance and its size relative to other objects in the visual field. This constructive process is revealed through a number of classic size illusions such as the Delboeuf Illusion, the Ebbinghaus Illusion and ot...
Article
This chapter begins by presenting a broad range of examples where attention can change how a single input is experienced. It presents a theory of attention that can account for all of the effects, as well as some new ones involving perceived colors in cases of overlapping transparent surfaces. It suggests that attention alters perceived appearances...