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Effects of adaptation on the perception of motion: The influence of competing mechanisms
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)
On the perception of relational motion
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)
Temporal and spatial determinants of induced shifts in perceived position
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)
attentional control of spatial perception
Title
The attentional control of spatial perception.
Creator
Balz, Gunther William, Florida Atlantic University, Hock, Howard S.
Abstract/Description
When perceivers examine a visual scene, they can control the extent to which their attention is either narrowly focused or spread over a larger spatial area. The experiments reported in this dissertation explore the consequences of narrow vs. broad attention for simple spatial discriminations as well as more complex cooperative interactions that are the basis for the self-organization of coherent motion patterns. Subjects' attentional spread (narrow or broad) is manipulated by means of a...
Show moreWhen perceivers examine a visual scene, they can control the extent to which their attention is either narrowly focused or spread over a larger spatial area. The experiments reported in this dissertation explore the consequences of narrow vs. broad attention for simple spatial discriminations as well as more complex cooperative interactions that are the basis for the self-organization of coherent motion patterns. Subjects' attentional spread (narrow or broad) is manipulated by means of a primary, luminance detection task. In conjunction with the luminance detection task is a secondary, spatial discrimination or detection task, which differs in the four reported experiments. In Experiment 1, the discrimination of misalignment of two visual elements is enhanced by narrowly focused attention. In Experiment 2, discrimination of horizontal spatial separation of two visual elements is improved for small inter-element distances by narrow attention and for relatively large inter-element distances by broad attention. Experiment 3 shows that the inter-element distance among counterphase-presented visual elements for which unidirectional and oscillatory motion patterns are observed with equal frequency depends on subjects' attentional spread. Narrow attention favors the oscillatory pattern and broad attention favors the unidirectional pattern. Experiment 4 shows that attentional spread has a minimal effect on the detection of motion, and, additionally that attentional effects on simple spatial judgments (Experiments 1 and 2) are too small to account for the large shift in the equi-probable boundary of reported unidirectional and oscillatory motion patterns found in Experiment 3. Therefore, it is concluded in conjunction with Hock and Balz's (1994) differential gradient model, that attentional spread influences the self-organization of unidirectional and oscillatory motion patterns through its effects on the relative strength of facilitating and inhibiting interactions among directionally selective motion detectors.
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Date Issued
1994
PURL
http://purl.flvc.org/fcla/dt/12392
Subject Headings
Attention, Selectivity (Psychology), Visual perception, Space perception
Format
Document (PDF)
Verb complexity effects: Thematic role assignment
Title
Verb complexity effects: Thematic role assignment.
Creator
Brookins, Bari Lynn., Florida Atlantic University, Hock, Howard S.
Abstract/Description
The aim of this project was to clarify the findings of Shapiro and Levine (1990) by exploring post-verb argument structure complexity effects. Three verb types, transitives, datives and obligatory three-place, were probed at four positions during an on-line sentence processing task that utilized cross-modal naming as the secondary task in a reaction time paradigm. No significant verb x probe interaction was found at any probe position with any of the three verb types. Two possible...
Show moreThe aim of this project was to clarify the findings of Shapiro and Levine (1990) by exploring post-verb argument structure complexity effects. Three verb types, transitives, datives and obligatory three-place, were probed at four positions during an on-line sentence processing task that utilized cross-modal naming as the secondary task in a reaction time paradigm. No significant verb x probe interaction was found at any probe position with any of the three verb types. Two possible explanations are given for this pattern of results: (1) the choice of cross-modal naming as the secondary task; and, (2) the high variability of reaction times among subjects.
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Date Issued
1996
PURL
http://purl.flvc.org/fcla/dt/15295
Subject Headings
Psycholinguistics, Comprehension, Semantics
Format
Document (PDF)
Competition between opposing motion directions in the perception of apparent motion: A new look at an old stimulus
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)
Cooperative self-organization in the perception of coherent motion
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)
Spontaneous pattern changes for bistable apparent motion stimuli: Perceptual satiation or memory attraction?
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)
Dynamic Grouping Motion and Amodal Completion
Title
Dynamic Grouping Motion and Amodal Completion.
Creator
Datta, Debarshi, Hock, Howard S., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Psychology
Abstract/Description
Objects in a scene are likely to occlude other objects partially and are itself likely to be partially occluded. A central question, therefore, is how the visual system resolves the resulting surface correspondence problem by successfully determining which surfaces belong to which objects. To this end, a recently developed dynamic grouping methodology has determined whether pairs of adjacent surfaces are grouped (Hock & Nichols, 2012). The grouping of adjacent surfaces, which depends on their...
Show moreObjects in a scene are likely to occlude other objects partially and are itself likely to be partially occluded. A central question, therefore, is how the visual system resolves the resulting surface correspondence problem by successfully determining which surfaces belong to which objects. To this end, a recently developed dynamic grouping methodology has determined whether pairs of adjacent surfaces are grouped (Hock & Nichols, 2012). The grouping of adjacent surfaces, which depends on their affinity state, is indicated by the direction of perceived motion across one surface when its luminance is perturbed. In the current stimuli, which consists of a horizontal surface partially occluded by a vertical bar, dynamic grouping also can occur for nonadjacent surfaces, providing they are linked in two-dimensions by a connecting surface. Results indicate that the dynamic grouping motion is stronger for amodal completion entailing the perceptual grouping of nonadjacent surfaces behind an occluder.
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Date Issued
2017
PURL
http://purl.flvc.org/fau/fd/FA00004998, http://purl.flvc.org/fau/fd/FA00004988
Subject Headings
Dissertations, Academic -- Florida Atlantic University, Visual perception., Visual system., Dynamic grouping
Format
Document (PDF)
TOP-DOWN EFFECTS OF PERCEPTUAL GROUPING ON THE PERCEPTION OF MOTION
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)
PERCEPTUAL SEGREGATION AND THE CATEGORY EFFECT
Title
PERCEPTUAL SEGREGATION AND THE CATEGORY EFFECT.
Creator
ROSENTHAL, ALAN., Florida Atlantic University, Hock, Howard S., Charles E. Schmidt College of Science, Department of Psychology
Abstract/Description
A category effect of alphanumeric characters in a visual search paradigm was examined to see whether the effect could be accounted for by the number of memory comparisons or by an early stage of perceptual processing. In Experiments 1 and 2, subjects searched for targets in either a within-category or between-category condition. The two experiments differed by the point in the trials where "catch trials" were presented. Experiment 3 used new configurations based on Gestalt principles which...
Show moreA category effect of alphanumeric characters in a visual search paradigm was examined to see whether the effect could be accounted for by the number of memory comparisons or by an early stage of perceptual processing. In Experiments 1 and 2, subjects searched for targets in either a within-category or between-category condition. The two experiments differed by the point in the trials where "catch trials" were presented. Experiment 3 used new configurations based on Gestalt principles which had been shown to influence target detection times at an early level of perceptual processing. The results of Experiments 1 and 2 favored a perceptual explanation mediating the effect. In Experiment 3, the critical interaction of category and Gestalt factors which would have demonstrated a competition in perceptually parsing the display fell short of significance.
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Date Issued
1980
PURL
http://purl.flvc.org/fcla/dt/14036
Subject Headings
Human information processing, Perception
Format
Document (PDF)
Potential stimulus contributions to counterchange determined motion perception
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)
Competing mechanisms in the perception of apparent motion: Effects of zero-hertz and time-varying energy
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)
Global feedback in hierarchical motion pattern formation
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)