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Title: TOP-DOWN EFFECTS OF PERCEPTUAL GROUPING ON THE PERCEPTION OF MOTION.
Creator: Datta, Debarshi, Hock, Howard S., Florida Atlantic University, Department of Psychology, Charles E. Schmidt College of Science
Abstract/Description: Ullman (1979) has proposed a measurement metric, which he termed “affinity." He described affinity as a certain similarity measure between successively presented surfaces as it affects the perception of apparent motion between the surfaces. Later, the concept of “affinity” has been extended; it entails that how the perception of motion within a surface is affected by its grouping strength with adjacent surfaces (Hock and Nichols, 2012). It has been found that the more attributes, that are...
Show moreUllman (1979) has proposed a measurement metric, which he termed “affinity." He described affinity as a certain similarity measure between successively presented surfaces as it affects the perception of apparent motion between the surfaces. Later, the concept of “affinity” has been extended; it entails that how the perception of motion within a surface is affected by its grouping strength with adjacent surfaces (Hock and Nichols, 2012). It has been found that the more attributes, that are shared by the adjacent surfaces, the greater the likelihood of their being grouped together. However, Ullman (1979) suggested that the relative affinities of pairs of surfaces could determine the solutions for the motion correspondence problem (when more than one motion path is possible). However, it has remained unknown whether the effects of affinity on solutions to the correspondence problem are due to its effects on a single surface apparent motion strength or pre-selection biases; i.e., the top-down effects of perceptual grouping favoring the perception of motion in one direction as opposed to other competing directions. In the current study, it has been confirmed that motion within a surface is affected by its affinity with adjacent surfaces. The current study also confirmed that affinity has a small, but significant effect on motion strength when motion surfaces are presented in a single surface apparent motion configuration, evidence for top-down effects in which motion strength can be affected by affinity. In motion correspondence problem, affinity affects the perceived motion direction due to competition is consistent with the solution to the motion correspondence problem being affected by the relative affinity-determined strength of competing motion signals. But it is seen that there is strong affinity is due to preselection identity biases. To conclude, in motion correspondence problem, stronger motion is perceived between the two similar surfaces is due to pre-selection biases resulting from the perceptual grouping of surfaces with the greatest affinity; i.e., the top-down effects favoring the perception of motion in one direction as opposed to other competing directions.
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Date Issued: 2020
PURL: http://purl.flvc.org/fau/fd/FA00013567
Subject Headings: Motion Perception, Perceptual grouping
Format: Document (PDF)

Title: Effects of adaptation on the perception of motion: The influence of competing mechanisms.
Creator: Espinoza, Jessica K., Florida Atlantic University, Hock, Howard S.
Abstract/Description: The effects of adaptation on motion were investigated using a modified apparent motion display. Unlike the classical apparent motion display, a BRLC (background relative luminance contrast) apparent motion display consists of two visible dots, each of a different luminance, which remain in the same position but exchange luminances on successive frames. This forms a bistable stimulus; stationarity-flicker or motion may be perceived, depending on the value of the BRLC. There was a significant...
Show moreThe effects of adaptation on motion were investigated using a modified apparent motion display. Unlike the classical apparent motion display, a BRLC (background relative luminance contrast) apparent motion display consists of two visible dots, each of a different luminance, which remain in the same position but exchange luminances on successive frames. This forms a bistable stimulus; stationarity-flicker or motion may be perceived, depending on the value of the BRLC. There was a significant interaction between condition (baseline or adaptation) and BRLC when testing motion perception following adaptation to a moving stimulus, a flickering stimulus and a static stimulus. Additionally, adaptation to flicker decreased motion perception at high BRLC values and increased it at low BRLC values. Our results reflected the presence of strong inhibitory competition between the mechanisms concerned with the perception of motion and stationarity which restricted adaptation effects to certain values of BRLC.
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Date Issued: 1998
PURL: http://purl.flvc.org/fcla/dt/15574
Subject Headings: Luminescence, Motion perception (Vision)
Format: Document (PDF)

Title: On the perception of relational motion.
Creator: Field, Linda C., Florida Atlantic University, Hock, Howard S.
Abstract/Description: Six experiments were performed to examine the adequacy of detection/computation models for understanding the perception of relational motion, and in particular, the perception of three-dimensional motion in two-dimensional displays. The stimuli were a pair of dots which moved relationally (i.e., the relative location of the dots changed). Three-dimensional motion was seen when a contraction of the stimulus preceded an expansion (i.e., the dot separation first decreased, then increased), the...
Show moreSix experiments were performed to examine the adequacy of detection/computation models for understanding the perception of relational motion, and in particular, the perception of three-dimensional motion in two-dimensional displays. The stimuli were a pair of dots which moved relationally (i.e., the relative location of the dots changed). Three-dimensional motion was seen when a contraction of the stimulus preceded an expansion (i.e., the dot separation first decreased, then increased), the angular difference between the pattern orientation and the direction of movement was small, and the spatial separation between dots was small. Neither the activation of higher-order, relational feature detectors, nor the construction/computation of relational motion from the detected motion of individual dots, can adequately explain the perception of three-dimensional motion.
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Date Issued: 1990
PURL: http://purl.flvc.org/fcla/dt/14630
Subject Headings: Motion perception (Vision)
Format: Document (PDF)

Title: A visual rotation invariant in fixated motion.
Creator: Ozery, Nissim Jossef., Florida Atlantic University, Raviv, Daniel, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: This thesis studies the 2-D-based visual invariant that exists during relative motion between a camera and a 3-D object. We show that during fixation there is a measurable nonlinear function of optical flow that produces the same value for all points of a stationary environment regardless of the 3-D shape of the environment. During fixated camera motion relative to a rigid object, e.g., a stationary environment, the projection of the fixated point remains (by definition) at the same location...
Show moreThis thesis studies the 2-D-based visual invariant that exists during relative motion between a camera and a 3-D object. We show that during fixation there is a measurable nonlinear function of optical flow that produces the same value for all points of a stationary environment regardless of the 3-D shape of the environment. During fixated camera motion relative to a rigid object, e.g., a stationary environment, the projection of the fixated point remains (by definition) at the same location in the image, and all other points located on the 3-D rigid object can only rotate relative to that 3-D fixation point. This rotation rate of the points is invariant for all points that lie on the particular environment, and it is measurable from a sequence of images. This new invariant is obtained from a set of monocular images and is expressed explicitly as a closed form solution.
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Date Issued: 1994
PURL: http://purl.flvc.org/fcla/dt/15095
Subject Headings: Invariants, Visual perception, Motion perception (Vision)
Format: Document (PDF)

Title: Cooperative self-organization in the perception of coherent motion.
Creator: Balz, Gunther William, Florida Atlantic University, Hock, Howard S.
Abstract/Description: A row of dots is presented in a series of alternating frames; dots in each frame are located at the midpoints between dots of the preceding frame. Although the perceived frame-to-frame direction of motion could vary randomly, cooperativity is indicated by the emergence of two coherent motion patterns, one unidirectional, the other oscillatory. Small increases in the time between frames are sufficient for the bias, which maintains the previously established motion direction (unidirectional...
Show moreA row of dots is presented in a series of alternating frames; dots in each frame are located at the midpoints between dots of the preceding frame. Although the perceived frame-to-frame direction of motion could vary randomly, cooperativity is indicated by the emergence of two coherent motion patterns, one unidirectional, the other oscillatory. Small increases in the time between frames are sufficient for the bias, which maintains the previously established motion direction (unidirectional motion), to be reversed, becoming a bias which inhibits that direction (oscillatory motion). Unidirectional motion, which predominates for small dot separations, and oscillatory motion, which predominates for large separations, are associated with short-range and long-range motion (Braddick, 1974) by manipulating the shape of the dots, their luminance, and the luminance of the inter-frame blank field. Pulsing/flicker emerges as a third perceptual state that competes with unidirectional motion for very small dot separations.
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Date Issued: 1991
PURL: http://purl.flvc.org/fcla/dt/14712
Subject Headings: Motion perception (Vision), Perceptual-motor learning
Format: Document (PDF)

Title: Spontaneous pattern changes for bistable apparent motion stimuli: Perceptual satiation or memory attraction?.
Creator: Voss, Audrey A., Florida Atlantic University, Hock, Howard S.
Abstract/Description: Subjects judge motion direction for an apparent motion stimulus with competing perceptual organizations: Vertical vs. horizontal motion. The two patterns are coupled. When one is perceptually instantiated the other remains active in memory, resulting in sudden changes in perceived motion direction under constant stimulus conditions. The probability of change from an initially horizontal to a vertical pattern remains constant over time, showing that perceptual satiation is insufficient to...
Show moreSubjects judge motion direction for an apparent motion stimulus with competing perceptual organizations: Vertical vs. horizontal motion. The two patterns are coupled. When one is perceptually instantiated the other remains active in memory, resulting in sudden changes in perceived motion direction under constant stimulus conditions. The probability of change from an initially horizontal to a vertical pattern remains constant over time, showing that perceptual satiation is insufficient to explain the occurrence of spontaneous perceptual changes. It is proposed that spontaneous changes also occur because the pattern active in memory attracts the percept away from the currently instantiated pattern. The attraction hypothesis specifies that the activation of the memory pattern (and hence its attractive strength) increases as a result of previous experience. It is supported by evidence that the likelihood of changing, say from horizontal to vertical motion, is increased if the motion pattern was previously vertical.
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Date Issued: 1991
PURL: http://purl.flvc.org/fcla/dt/14721
Subject Headings: Motion perception (Vision), Perceptual-motor learning
Format: Document (PDF)

Title: Competing mechanisms in the perception of apparent motion: Effects of zero-hertz and time-varying energy.
Creator: Kogan, Kristine Marie, Florida Atlantic University, Hock, Howard S., Charles E. Schmidt College of Science, Department of Psychology
Abstract/Description: Anstis, et al. (1985) have reported that under certain conditions the visual system adapts and the perception of apparent motion breaks down. The present research indicates that breakdown is actually a result of same-place mechanisms successfully competing with motion-detecting mechanisms. Thus, the perception of stationarity (with flicker) can occur at the start of a trial and spontaneously switch to the perception of motion, or vice versa. The response of same-place mechanisms depends on...
Show moreAnstis, et al. (1985) have reported that under certain conditions the visual system adapts and the perception of apparent motion breaks down. The present research indicates that breakdown is actually a result of same-place mechanisms successfully competing with motion-detecting mechanisms. Thus, the perception of stationarity (with flicker) can occur at the start of a trial and spontaneously switch to the perception of motion, or vice versa. The response of same-place mechanisms depends on the zero-hertz energy at each location of an apparent motion stimulus, whereas the response of motion mechanisms depends on the time-varying energy. Average luminance, luminance contrast, the temporal symmetry of the apparent motion display, and relative phase are manipulated to investigate competition between same-place and motion-detecting mechanisms.
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Date Issued: 1995
PURL: http://purl.flvc.org/fcla/dt/15234
Subject Headings: Motion perception (Vision), Perceptual-motor processes, Visual perception
Format: Document (PDF)

Title: COLLISION FREE NAVIGATION IN 3D UNSTRUCTURED ENVIRONMENTS USING VISUAL LOOMING.
Creator: Yepes, Juan David Arango, Raviv, Daniel, Florida Atlantic University, Department of Computer and Electrical Engineering and Computer Science, College of Engineering and Computer Science
Abstract/Description: Vision is a critical sense for many species, with the perception of motion being a fundamental aspect. This aspect often provides richer information than static images for understanding the environment. Motion recognition is a relatively simple computation compared to shape recognition. Many creatures can discriminate moving objects quite well while having virtually no capacity for recognizing stationary objects. Traditional methods for collision-free navigation require the reconstruction of...
Show moreVision is a critical sense for many species, with the perception of motion being a fundamental aspect. This aspect often provides richer information than static images for understanding the environment. Motion recognition is a relatively simple computation compared to shape recognition. Many creatures can discriminate moving objects quite well while having virtually no capacity for recognizing stationary objects. Traditional methods for collision-free navigation require the reconstruction of a 3D model of the environment before planning an action. These methods face numerous limitations as they are computationally expensive and struggle to scale in unstructured and dynamic environments with a multitude of moving objects. This thesis proposes a more scalable and efficient alternative approach without 3D reconstruction. We focus on visual motion cues, specifically ’visual looming’, the relative expansion of objects on an image sensor. This concept allows for the perception of collision threats and facilitates collision-free navigation in any environment, structured or unstructured, regardless of the vehicle’s movement or the number of moving objects present.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014239
Subject Headings: Motion perception (Vision), Collision avoidance systems, Visual perception
Format: Document (PDF)

Title: Temporal and spatial determinants of induced shifts in perceived position.
Creator: Eastman, Kathleen E., Florida Atlantic University, Hock, Howard S.
Abstract/Description: The effects of the onset, offset, and sustained presence of inducing lines on the perceived position of test lines were independently investigated in a vernier alignment task. For spatial separations larger than 2.3 min, repulsion effects were always observed. For the smallest spatial separation, 2.3 min, the effect of the inducing lines was attraction for 0 and 195 SOAs. Minimal attraction was observed for a 3000 SOA. However, when the offset effect was isolated using the 3000 SOA and a 0...
Show moreThe effects of the onset, offset, and sustained presence of inducing lines on the perceived position of test lines were independently investigated in a vernier alignment task. For spatial separations larger than 2.3 min, repulsion effects were always observed. For the smallest spatial separation, 2.3 min, the effect of the inducing lines was attraction for 0 and 195 SOAs. Minimal attraction was observed for a 3000 SOA. However, when the offset effect was isolated using the 3000 SOA and a 0 ISI, a large repulsion effect was observed for the 2.3 min spatial separation, as well as for the larger spatial separations. These results indicate that the temporal separation between visual elements is as important in determining perceived position as their spatial separation, which has been demonstrated in earlier studies (Badcock & Westheimer, 1985). A differential gradient model is proposed which accounts for these findings in terms of excitatory and inhibitory interactions within an ensemble of position-sensitive units.
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Date Issued: 1993
PURL: http://purl.flvc.org/fcla/dt/14897
Subject Headings: Visual perception, Space perception, Motion perception (Vision), Figure-ground perception
Format: Document (PDF)

Title: Two-dimensional feature tracking algorithm for motion analysis.
Creator: Krishnan, Srivatsan., Florida Atlantic University, Raviv, Daniel, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: In this thesis we describe a local-neighborhood-pixel-based adaptive algorithm to track image features, both spatially and temporally, over a sequence of monocular images. The algorithm assumes no a priori knowledge about the image features to be tracked, or the relative motion between the camera and the 3-D objects. The features to be tracked are selected by the algorithm and they correspond to the peaks of '2-D intensity correlation surface' constructed from a local neighborhood in the...
Show moreIn this thesis we describe a local-neighborhood-pixel-based adaptive algorithm to track image features, both spatially and temporally, over a sequence of monocular images. The algorithm assumes no a priori knowledge about the image features to be tracked, or the relative motion between the camera and the 3-D objects. The features to be tracked are selected by the algorithm and they correspond to the peaks of '2-D intensity correlation surface' constructed from a local neighborhood in the first image of the sequence to be analyzed. Any kind of motion, i.e., 6 DOF (translation and rotation), can be tolerated keeping in mind the pixels-per-frame motion limitations. No subpixel computations are necessary. Taking into account constraints of temporal continuity, the algorithm uses simple and efficient predictive tracking over multiple frames. Trajectories of features on multiple objects can also be computed. The algorithm accepts a slow, continuous change of brightness D.C. level in the pixels of the feature. Another important aspect of the algorithm is the use of an adaptive feature matching threshold that accounts for change in relative brightness of neighboring pixels. As applications of the feature-tracking algorithm and to test the accuracy of the tracking, we show how the algorithm has been used to extract the Focus of Expansion (FOE) and compute the Time-to-contact using real image sequences of unstructured, unknown environments. In both these applications, information from multiple frames is used.
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Date Issued: 1994
PURL: http://purl.flvc.org/fcla/dt/15030
Subject Headings: Algorithms, Image transmission, Motion perception (Vision), Image processing
Format: Document (PDF)

Title: Potential stimulus contributions to counterchange determined motion perception.
Creator: Park, Cynthia Louise Smith, Hock, Howard S., Barenholtz, Elan, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Psychology
Abstract/Description: Prior research has explored the counterchange model of motion detection in terms of counterchanging information that originates in the stimulus foreground (or objects). These experiments explore counterchange apparent motion with regard to a new apparent motion stimulus where the necessary counterchanging information required for apparent motion is provided by altering the luminance of the background. It was found that apparent motion produced by background-counterchange requires longer frame...
Show morePrior research has explored the counterchange model of motion detection in terms of counterchanging information that originates in the stimulus foreground (or objects). These experiments explore counterchange apparent motion with regard to a new apparent motion stimulus where the necessary counterchanging information required for apparent motion is provided by altering the luminance of the background. It was found that apparent motion produced by background-counterchange requires longer frame durations and lower levels of average stimulus contrast compared to foreground-counterchange. Furthermore, inter-object distance does not influence apparent motion produced by background-counterchange to the degree it influences apparent motion produced by foreground-counterchange.
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Date Issued: 2014
PURL: http://purl.flvc.org/fau/fd/FA00004313
Subject Headings: Motion perception (Vision), Perceptual motor processes, Visual analysis, Visual discrimination, Visual pathways, Visual perception
Format: Document (PDF)

Title: Competition between opposing motion directions in the perception of apparent motion: A new look at an old stimulus.
Creator: Huisman, Avia, Florida Atlantic University, Hock, Howard S.
Abstract/Description: This study tested the hypothesis that the perception of 2-flash apparent motion (points of light are briefly presented in succession at a nearby locations) is the outcome of competition between two opposing motion directions activated by the stimulus. Experiment 1 replicated previous results obtained using 2-flash stimuli; motion was optimal for a non-zero inter-frame interval (Kolers, 1972; Wertheimer, 1912). In Experiment 2, stimuli were pared down to a single luminance change toward the...
Show moreThis study tested the hypothesis that the perception of 2-flash apparent motion (points of light are briefly presented in succession at a nearby locations) is the outcome of competition between two opposing motion directions activated by the stimulus. Experiment 1 replicated previous results obtained using 2-flash stimuli; motion was optimal for a non-zero inter-frame interval (Kolers, 1972; Wertheimer, 1912). In Experiment 2, stimuli were pared down to a single luminance change toward the background at one location, and a single luminance change away from the background at one location at another. Results were consistent with apparent motion being specified by the counter-changing luminance; motion was optimal for a non-zero inter-frame interval. A subtractive model based on counter-change stimulating opposing motion directions did not account for the results of the 2-flash experiment. An alternative model based on the combined transient responses of biphasic detectors is discussed.
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Date Issued: 2005
PURL: http://purl.flvc.org/fcla/dt/13209
Subject Headings: Contrast sensitivity (Vision), Visual perception, Motion perception (Vision), Movement, Psychology of
Format: Document (PDF)

Title: Global feedback in hierarchical motion pattern formation.
Creator: Brownlow, Stacey W., Florida Atlantic University, Hock, Howard S., Charles E. Schmidt College of Science, Department of Psychology
Abstract/Description: An array of four motion quartets (stimuli for which either horizontal or vertical motion is perceived depending on quartet aspect ratio) is arranged in a diamond configuration such that two global motion patterns are formed: (1) Rotation---alternating counterclockwise and clockwise motion is perceived, and (2) Parallel path motion---the perceived motions of all the elements are simultaneously horizontal or simultaneously vertical. The perception of rotation resulted in global feedback that...
Show moreAn array of four motion quartets (stimuli for which either horizontal or vertical motion is perceived depending on quartet aspect ratio) is arranged in a diamond configuration such that two global motion patterns are formed: (1) Rotation---alternating counterclockwise and clockwise motion is perceived, and (2) Parallel path motion---the perceived motions of all the elements are simultaneously horizontal or simultaneously vertical. The perception of rotation resulted in global feedback that biases the motion perceived for an individual component motion quartet to be more consistent with rotation than aspect ratio. Stronger rotation produced greater bias. Under certain conditions, the feedback-induced bias occurred even though global rotation was not perceived. The results were interpreted in the context of neurophysiological evidence regarding neurons in Areas MT and MSTd, and a dynamical theory of motion pattern formation (Hock, Schoner & Giese, 2003; Nichols, Hock & Schoner, 2006).
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Date Issued: 2006
PURL: http://purl.flvc.org/fcla/dt/13371
Subject Headings: Motion perception (Vision)--Mathematical models, Visual pathways, Neurophysiology, Nonlinear chemical kinetics
Format: Document (PDF)

Motion perception (Vision) (11)	+ -
Visual perception (6)	+ -
Perceptual-motor learning (2)	+ -
Visual pathways (2)	+ -
Algorithms (1)	+ -

Collision avoidance systems (1)	+ -
Contrast sensitivity (Vision) (1)	+ -
Figure-ground perception (1)	+ -
Image processing (1)	+ -
Image transmission (1)	+ -
Invariants (1)	+ -
Luminescence (1)	+ -
Motion Perception (1)	+ -
Motion perception (Vision)--Mathematical models (1)	+ -
Movement, Psychology of (1)	+ -
Neurophysiology (1)	+ -
Nonlinear chemical kinetics (1)	+ -
Perceptual grouping (1)	+ -
Perceptual motor processes (1)	+ -
Perceptual-motor processes (1)	+ -
Space perception (1)	+ -
Visual analysis (1)	+ -
Visual discrimination (1)	+ -

Florida Atlantic University (13)	+ -
Hock, Howard S. (10)	+ -
Charles E. Schmidt College of Science (4)	+ -
Department of Psychology (4)	+ -
College of Engineering and Computer Science (3)	+ -

Department of Computer and Electrical Engineering and Computer Science (3)	+ -
Raviv, Daniel (3)	+ -
Balz, Gunther William (1)	+ -
Barenholtz, Elan (1)	+ -
Brownlow, Stacey W. (1)	+ -
Datta, Debarshi (1)	+ -
Eastman, Kathleen E. (1)	+ -
Espinoza, Jessica K. (1)	+ -
Field, Linda C. (1)	+ -
Huisman, Avia (1)	+ -
Kogan, Kristine Marie (1)	+ -
Krishnan, Srivatsan. (1)	+ -
Ozery, Nissim Jossef. (1)	+ -
Park, Cynthia Louise Smith (1)	+ -
Voss, Audrey A. (1)	+ -
Yepes, Juan David Arango (1)	+ -

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