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Title: Eye Fixations of the Face Are Modulated by Perception of a Bidirectional Social Interaction.
Creator: Kleiman, Michael J., Barenholtz, Elan, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Psychology
Abstract/Description: Eye fixations of the face are normally directed towards either the eyes or the mouth, however the proportions of gaze to either of these regions are dependent on context. Previous studies of gaze behavior demonstrate a tendency to stare into a target’s eyes, however no studies investigate the differences between when participants believe they are engaging in a live interaction compared to knowingly watching a pre-recorded video, a distinction that may contribute to studies of memory encoding....
Show moreEye fixations of the face are normally directed towards either the eyes or the mouth, however the proportions of gaze to either of these regions are dependent on context. Previous studies of gaze behavior demonstrate a tendency to stare into a target’s eyes, however no studies investigate the differences between when participants believe they are engaging in a live interaction compared to knowingly watching a pre-recorded video, a distinction that may contribute to studies of memory encoding. This study examined differences in fixation behavior for when participants falsely believed they were engaging in a real-time interaction over the internet (“Real-time stimulus”) compared to when they knew they were watching a pre-recorded video (“Pre-recorded stimulus”). Results indicated that participants fixated significantly longer towards the eyes for the pre-recorded stimulus than for the real-time stimulus, suggesting that previous studies which utilize pre-recorded videos may lack ecological validity.
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Date Issued: 2016
PURL: http://purl.flvc.org/fau/fd/FA00004701, http://purl.flvc.org/fau/fd/FA00004701
Subject Headings: Eye -- Movements, Eye tracking, Gaze -- Psychological aspects, Nonverbal communication, Optical pattern recognition, Perceptual motor processes, Visual perception
Format: Document (PDF)

Title: Flexible Attentional Prioritization of Working Memory Object Representations.
Creator: Pytel, Paige, Ester, Edward, Florida Atlantic University, Department of Psychology, Charles E. Schmidt College of Science
Abstract/Description: Working memory (WM) is an important cognitive function that, among other duties, allows temporary storage of visual representations of objects observed in the sensorium. The visual aspect of this core cognitive function enables our perception of the identity of objects and where those objects are located in space at any particular time to help direct attention. In a typical working memory task, a cue is presented beforehand to guide attention to which objects in an array to encode. The...
Show moreWorking memory (WM) is an important cognitive function that, among other duties, allows temporary storage of visual representations of objects observed in the sensorium. The visual aspect of this core cognitive function enables our perception of the identity of objects and where those objects are located in space at any particular time to help direct attention. In a typical working memory task, a cue is presented beforehand to guide attention to which objects in an array to encode. The performance of our WM abilities can be improved on memory tasks by a retrospective cue resented after the encoding process of working memory. Several mechanisms have been proposed to explain etrospective cue benefits in WM performance, including the removal of irrelevant information from WM, attentional enhancement of the cued representation, protection of the cued representation from subsequent decay or interference, or retrieval head start.
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Date Issued: 2019
PURL: http://purl.flvc.org/fau/fd/FA00013406
Subject Headings: Memory, Short-Term, Cues, Visual perception, Electroencephalography
Format: Document (PDF)

Title: A theory for the visual perception of object motion.
Creator: Norman, Joseph W., Barenholtz, Elan, Florida Atlantic University, Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
Abstract/Description: The perception of visual motion is an integral aspect of many organisms' engagement with the world. In this dissertation, a theory for the perception of visual object-motion is developed. Object-motion perception is distinguished from objectless-motion perception both experimentally and theoretically. A continuoustime dynamical neural model is developed in order to generalize the ndings and provide a theoretical framework for continued re nement of a theory for object-motion perception....
Show moreThe perception of visual motion is an integral aspect of many organisms' engagement with the world. In this dissertation, a theory for the perception of visual object-motion is developed. Object-motion perception is distinguished from objectless-motion perception both experimentally and theoretically. A continuoustime dynamical neural model is developed in order to generalize the ndings and provide a theoretical framework for continued re nement of a theory for object-motion perception. Theoretical implications as well as testable predictions of the model are discussed.
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Date Issued: 2014
PURL: http://purl.flvc.org/fau/fd/FA00004221, http://purl.flvc.org/fau/fd/FA00004221
Subject Headings: Human information processing, Neurophysiology, Perceptual motor processes, Visual perception
Format: Document (PDF)

Title: How the Spatial Organization of Objects Affects Perceptual Processing of a Scene.
Creator: Rashford, Stacey, Barenholtz, Elan, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Psychology
Abstract/Description: How does spatial organization of objects affect the perceptual processing of a scene? Surprisingly, little research has explored this topic. A few studies have reported that, when simple, homogenous stimuli (e.g., dots), are presented in a regular formation, they are judged to be more numerous than when presented in a random configuration (Ginsburg, 1976; 1978). However, these results may not apply to real-world objects. In the current study, fewer objects were believed to be on organized...
Show moreHow does spatial organization of objects affect the perceptual processing of a scene? Surprisingly, little research has explored this topic. A few studies have reported that, when simple, homogenous stimuli (e.g., dots), are presented in a regular formation, they are judged to be more numerous than when presented in a random configuration (Ginsburg, 1976; 1978). However, these results may not apply to real-world objects. In the current study, fewer objects were believed to be on organized desks than their disorganized equivalents. Objects that are organized may be more likely to become integrated, due to classic Gestalt principles. Consequently, visual search may be more difficult. Such object integration may diminish saliency, making objects less apparent and more difficult to find. This could explain why, in the present study, objects on disorganized desks were found faster.
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Date Issued: 2015
PURL: http://purl.flvc.org/fau/fd/FA00004537, http://purl.flvc.org/fau/fd/FA00004537
Subject Headings: Image analysis, Optical pattern recognition, Pattern recognition systems, Phenomenological psychology, Visual perception
Format: Document (PDF)

Title: Peripheral Object Recognition in Naturalistic Scenes.
Creator: Schlangen, Derrick, Barenholtz, Elan, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Psychology
Abstract/Description: Most of the human visual field falls in the periphery, and peripheral processing is important for normal visual functioning. Yet, little is known about peripheral object recognition in naturalistic scenes and factors that modulate this ability. We propose that a critical function of scene and object memory is in order to facilitate visual object recognition in the periphery. In the first experiment, participants identified objects in scenes across different levels of familiarity and...
Show moreMost of the human visual field falls in the periphery, and peripheral processing is important for normal visual functioning. Yet, little is known about peripheral object recognition in naturalistic scenes and factors that modulate this ability. We propose that a critical function of scene and object memory is in order to facilitate visual object recognition in the periphery. In the first experiment, participants identified objects in scenes across different levels of familiarity and contextual information within the scene. We found that familiarity with a scene resulted in a significant increase in the distance that objects were recognized. Furthermore, we found that a semantically consistent scene improved the distance that object recognition is possible, supporting the notion that contextual facilitation is possible in the periphery. In the second experiment, the preview duration of a scene was varied in order to examine how a scene representation is built and how memory of that scene and the objects within it contributes to object recognition in the periphery. We found that the closer participants fixated to the object in the preview, the farther on average they recognized that target object in the periphery. However, only a preview duration of the scenes for 5000 ms produced significantly farther peripheral object recognition compared to not previewing the scene. Overall, these experiments introduce a novel research paradigm for object recognition in naturalistic scenes, and demonstrates multiple factors that have systematic effects on peripheral object recognition.
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Date Issued: 2016
PURL: http://purl.flvc.org/fau/fd/FA00004669, http://purl.flvc.org/fau/fd/FA00004669
Subject Headings: Context effects (Psychology), Human information processing, Optical pattern recognition, Pattern recognition systems, Recognition (Psychology), Visual perception
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: Traveling Waves of Dominance in Motion-Induced Blindness.
Creator: Cox, Dustin, Hong, Sang Wook, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Psychology
Abstract/Description: In the present study, it was examined whether the spatiotemporal dynamics of transitions towards target dominance in motion-induced blindness (MIB) were wave-like, similar to those in binocular rivalry. The spatiotemporal dynamics of transitions towards dominance in MIB were further compared with those in binocular rivalry to reveal a potential neural locus of MIB. Across a series of experiments, the relationship between target length, stimulus structure, presentation location and the latency...
Show moreIn the present study, it was examined whether the spatiotemporal dynamics of transitions towards target dominance in motion-induced blindness (MIB) were wave-like, similar to those in binocular rivalry. The spatiotemporal dynamics of transitions towards dominance in MIB were further compared with those in binocular rivalry to reveal a potential neural locus of MIB. Across a series of experiments, the relationship between target length, stimulus structure, presentation location and the latency for circular arc segment-shaped targets to reappear was examined, respectively. It was found that target reappearance durations increase with target length, as if they reappear in a gradual, wavelike fashion. Target reappearance durations were decreased for collinear compared to radial targets, but they were not influenced by the location of target presentation. The results suggest MIB target reappearances are associated with traveling waves of dominance, and early visual cortex is a likely neural substrate in which these wave-like transitions occur.
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Date Issued: 2016
PURL: http://purl.flvc.org/fau/fd/FA00004704, http://purl.flvc.org/fau/fd/FA00004704
Subject Headings: Binocular rivalry, Binocular vision, Visual pathways, Visual perception
Format: Document (PDF)

Title: The Significance for, and Impact Upon, Public Administration of the Correspondence Theory of Truth or Veridicality.
Creator: Slagle, Derek Ray, Miller, Hugh T., Florida Atlantic University, College for Design and Social Inquiry, School of Public Administration
Abstract/Description: The dissertation is about the significance for, and impact upon public administration of the correspondence theory of truth or veridicality, and its underlying epistemological assumptions. The underlying thesis is that, unduly influenced by the success of the natural sciences, and naive in accepting their claims to objectivity, many disciplines have sought to emulate them. There are two principle objections. Firstly, all other considerations aside, the supposedly objectivistic methodologies...
Show moreThe dissertation is about the significance for, and impact upon public administration of the correspondence theory of truth or veridicality, and its underlying epistemological assumptions. The underlying thesis is that, unduly influenced by the success of the natural sciences, and naive in accepting their claims to objectivity, many disciplines have sought to emulate them. There are two principle objections. Firstly, all other considerations aside, the supposedly objectivistic methodologies apparently applied to the explanation and prediction of the behavior of interactions of physical objects, may simply be inappropriate to certain other areas of inquiry; and more specifically objectivist methodologies are indeed inappropriate to understanding of human subjects, and their behavior, relations and interactions, and thus to public administration. The second objection is that it is of course logically impossible for any supposedly empirical discipline, as the natural sciences claim to be, to justify the belief in a supposedly objective realm of things-in-themselves existing outside, beyond, or independently of the changing, interrupted and different 'appearances' or experiences, to which an empirical science is qua empirical, necessarily restricted. Correspondence of any empirical observations or appearances (and the consequent or presupposed theoretical explanations) to an objective realm, upon which the claim to objectivity is based, is unverifiable. In light of the above it becomes evident that far from being objective, the natural sciences themselves, and the empirical observations upon which they are supposedly grounded, are subject to conceptual mediation and subjective interpretation; subjective and inter-subjective coherence replacing objective correspondence as the criterion of veridicality. Consequently it becomes clear that the presuppositions and prejudices of the observers enter, in the forms of concepts and preconceptions, into the very observations, and even more so into the theoretical constructions, or theories, of the natural, and indeed human and social sciences, and their claims to be authoritative and true. Subsequent discussion is then focused on both the coherence of individuals' experiences and understanding, and their inter-subjective coherence - which both rises from and constitutes, a "community". The role of language facilitates such coherence.
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Date Issued: 2015
PURL: http://purl.flvc.org/fau/fd/FA00004548, http://purl.flvc.org/fau/fd/FA00004548
Subject Headings: Discourse analysis, Information theory -- Philosophy, Philosophy of mind, Polarity (Linguistics), Public administration -- Language, Public administration -- Research -- Philosophy, Social constructivism, Visual perception
Format: Document (PDF)

Title: Investigating the Temporal Dynamics of Advanced Information Processing During Interocular Suppression Using Electroencephalography and Pattern Classification.
Creator: Cox, Dustin, Hong, Sang Wook, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Psychology
Abstract/Description: A thorough delineation of the extent of processing possible without visual awareness is necessary to elucidate the neural mechanisms of visual awareness. Despite extensive research, it is presently unclear whether invisible stimuli can undergo advanced processing. To introduce existing work on this topic, previous behavioral efforts to investigate the extent of processing possible without visual awareness and the psychophysical methods used to render stimuli invisible, such as visual masking...
Show moreA thorough delineation of the extent of processing possible without visual awareness is necessary to elucidate the neural mechanisms of visual awareness. Despite extensive research, it is presently unclear whether invisible stimuli can undergo advanced processing. To introduce existing work on this topic, previous behavioral efforts to investigate the extent of processing possible without visual awareness and the psychophysical methods used to render stimuli invisible, such as visual masking and interocular suppression-based techniques, are discussed. Physiological evidence that provide support for and against the possibility that advanced information processing can occur without visual awareness are addressed. The basics of multivariate pattern classification techniques are outlined. The potential of using multivariate pattern classification analyses in conjunction with neuroimaging in the temporal domain to investigate whether advanced processing can occur without visual awareness is discussed. An original study using electroencephalography (EEG) and pattern classification techniques to investigate the extent of processing possible without visual awareness is outlined. The results of the analyses reveal that a pattern classifier did not extract neural signatures of categorical processing from EEG recordings when participants viewed an image that remained invisible for the duration of its presentation. In contrast, the results from a second experiment reveal that the pattern classifier was able to decode the category of invisible images from the EEG time series when the images would eventually become visible. The results provide support for the idea that under certain circumstances, such as when the depth of interocular suppression is reduced, advanced processing for invisible stimuli can occur.
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Date Issued: 2019
PURL: http://purl.flvc.org/fau/fd/FA00013193
Subject Headings: Advanced information processing, Electroencephalography, Neuroimaging, Visual perception
Format: Document (PDF)

Title: Autonomous landing and road following using two-dimensional visual cues.
Creator: Yakali, Huseyin Hakan., Florida Atlantic University, Raviv, Daniel, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: This dissertation deals with vision-based perception-action closed-loop control systems based on 2-D visual cues. These visual cues are used to calculate the relevant control signals required for autonomous landing and road following. In the landing tasks it has been shown that nine 2-D visual cues can be extracted from a single image of the runway. Seven of these cues can be used to accomplish parallel flight and glideslope tracking tasks of the landing. For the road following task, three...
Show moreThis dissertation deals with vision-based perception-action closed-loop control systems based on 2-D visual cues. These visual cues are used to calculate the relevant control signals required for autonomous landing and road following. In the landing tasks it has been shown that nine 2-D visual cues can be extracted from a single image of the runway. Seven of these cues can be used to accomplish parallel flight and glideslope tracking tasks of the landing. For the road following task, three different algorithms based on two different 2-D visual cues are developed. One of the road following algorithms can be used to generate steering and velocity commands for the vehicle. Glideslope tracking of the landing task has been implemented in real-time on a six-degree-of-freedom flight simulator. It has been shown that the relevant information computed from 2-D visual cues is robust and reliable for the landing tasks. Road following algorithms were tested successfully up to 50km/h on a US Army High Mobility and Multipurpose Wheeled Vehicle (HMMWV) equipped with a vision system and on a Denning mobile robot. The algorithms have also been tested successfully using PC-based software simulation programs.
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Date Issued: 1994
PURL: http://purl.flvc.org/fcla/dt/12365
Subject Headings: Visual perception, Landing aids (Aeronautics)
Format: Document (PDF)

Title: AN EXAMINATION OF CONTEXT EFFECTS IN VISUAL PERCEPTION.
Creator: GORDON, GREGORY PETER, Florida Atlantic University
Abstract/Description: A "same-different" reaction time paradigm was used to investigate the influence of context on the perception of multiple object scenes consisting of "real-world" objects. The relationships among these objects were manipulated to compose four different contextual arrangements. This enabled an investigation of three aspects of context: familiarity, physical plausibility, and belongingness. Differences in reaction time between the four levels of context were significant for both same and...
Show moreA "same-different" reaction time paradigm was used to investigate the influence of context on the perception of multiple object scenes consisting of "real-world" objects. The relationships among these objects were manipulated to compose four different contextual arrangements. This enabled an investigation of three aspects of context: familiarity, physical plausibility, and belongingness. Differences in reaction time between the four levels of context were significant for both same and different responses. Furthermore, a correlational analysis indicated individual differences in the use of contextual effects. Those subjects who were most influenced by whether or not the objects belonged together, were least influenced by the disruption of the rules of physical plausibility, and vice versa. Correlational analyses concerned with the relationship between individual differences in context effects and emphasis on structural versus analytic processing (Hock, 1973) were insignificant, though in the predicted direction.
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Date Issued: 1973
PURL: http://purl.flvc.org/fcla/dt/13558
Subject Headings: Visual perception
Format: Document (PDF)

Title: Binding Errors and their Relationship to Object-Present and Object-Absent Motion Events.
Creator: Pacific, Justin Brooks, Kersten, Alan, Florida Atlantic University, Department of Psychology, Charles E. Schmidt College of Science
Abstract/Description: The current study sought to examine further the concept of eyewitness memory for events. Specifically, using filmed events that were performed with objects and events performed without objects, we explored the potential interaction of the object cue and binding or conjunction errors. This specific memory error involves improperly pairing two or more feature memories together in the long-term store. In our study, these features were the action and the actress performing the action. Our study...
Show moreThe current study sought to examine further the concept of eyewitness memory for events. Specifically, using filmed events that were performed with objects and events performed without objects, we explored the potential interaction of the object cue and binding or conjunction errors. This specific memory error involves improperly pairing two or more feature memories together in the long-term store. In our study, these features were the action and the actress performing the action. Our study involved 51 participants. Participants were shown target events in Week 1 and asked to retrieve the target events from a larger group of events in Week 2. While findings did not show the expected interaction of conjunction events to object presence or absence, objects without an object showed a significantly higher acceptance rate. A secondary analysis revealed an interaction effect between head-focus and recognition item type, meaning participants did view events without an object differently from objects with an object.
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Date Issued: 2006
PURL: http://purl.flvc.org/fau/fd/FA00000804
Subject Headings: Context effects (Psychology), Eyewitness identification, Recollection (Psychology), Visual perception
Format: Document (PDF)

Title: Enhancing video quality based on psychophysical studies of smooth pursuit eye movements.
Creator: Chilamakuri, Pavani., Florida Atlantic University, Furht, Borko, Glenn, William E., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: When motion occurs in a scene, the quality of video degrades due to motion smear, which results in a loss of contrast in the image. The characteristics of the human vision system when smooth pursuit eye movements occur are different from those when the eye fixates on an object such as a video screen during motion. Smooth pursuit eye movements dominate in the presence of dynamic stimuli. In the presence of smooth pursuit eye movements, the contrast sensitivity for increasing target velocities...
Show moreWhen motion occurs in a scene, the quality of video degrades due to motion smear, which results in a loss of contrast in the image. The characteristics of the human vision system when smooth pursuit eye movements occur are different from those when the eye fixates on an object such as a video screen during motion. Smooth pursuit eye movements dominate in the presence of dynamic stimuli. In the presence of smooth pursuit eye movements, the contrast sensitivity for increasing target velocities shifts toward lower spatial frequencies. The sensitivity for low spatial frequencies during motion is higher than for a stationary case. This dissertation will propose a method to improve the perceptual quality of video using temporal enhancement prefiltering technique based on the characteristics of Smooth Pursuit Eye Movements (SPEM). The resulting technique closely matches the characteristics of the human visual system (HVS). When motion occurs, the eye tracks the moving targets in a scene as opposed to fixating on any portion of the scene. Hence, psychophysical studies of smooth pursuit eye movements were used as a basis to design the temporal filters. Results of experiments show that temporal enhancement results in improved quality by increasing the apparent sharpness of the image sequence. In this dissertation, a study of research describing how motion affects the image quality at the camera lens and the human eye is presented. This dissertation uses that research to develop a temporal enhancement technique to improve the quality of video degraded by motion.
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Date Issued: 2003
PURL: http://purl.flvc.org/fau/fd/FADT12035
Subject Headings: Eye--Movements, Digital video, Visual perception, Video compression
Format: Document (PDF)

Title: THE INTENSITY OF HOPKINS' VISUAL PERCEPTION.
Creator: MILLER, JANE TURTON., Florida Atlantic University, Nathan, Norman
Abstract/Description: The remarkable genius of Gerard Manley Hopkins' visual perception, as revealed in his journals and poems, is a product of the intensity with which the poet conceives a thing in terms of the physical action prompted by it, and is the result of the vibrant joining of perceiver and percept. He defines a scene so that the reader may see and praise God, the Creator of each thing in the landscape. The joining of God, perceiver, and percept is a dynamic communion charged with energy. According to...
Show moreThe remarkable genius of Gerard Manley Hopkins' visual perception, as revealed in his journals and poems, is a product of the intensity with which the poet conceives a thing in terms of the physical action prompted by it, and is the result of the vibrant joining of perceiver and percept. He defines a scene so that the reader may see and praise God, the Creator of each thing in the landscape. The joining of God, perceiver, and percept is a dynamic communion charged with energy. According to Hopkins, the flow of language should match the original sensation of the single unified effect upon the beholder of the scene; such a sensation appears in direct relationship to the intensity of the poet's visual interpretation of the scene.
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Date Issued: 1976
PURL: http://purl.flvc.org/fcla/dt/13829
Subject Headings: Hopkins, Gerard Manley,--1844-1889, Visual perception
Format: Document (PDF)

Title: HEMISPHERIC DIFFERENCES IN THE EFFECT OF STIMULUS FAMILIARITY ON PERCEIVED DURATION.
Creator: MURPHY, ARTHUR LORD, Florida Atlantic University
Abstract/Description: A paired-comparisons procedure was used to obtain relative duration judgements of identical pairs of normal (e.g. A vs. A) or rotated (e.g.V vs.V) letters. Each pair of letters was presented simultaneously for a duration of 50msec, with one letter in the LVF (left visual field, right hemisphere), and one in the RVF (right visual field, left hemisphere). It was hypothesized that LVF presentations of rotated letters would have a greater apparent duration . This was based on Hock, Kronseder, and...
Show moreA paired-comparisons procedure was used to obtain relative duration judgements of identical pairs of normal (e.g. A vs. A) or rotated (e.g.V vs.V) letters. Each pair of letters was presented simultaneously for a duration of 50msec, with one letter in the LVF (left visual field, right hemisphere), and one in the RVF (right visual field, left hemisphere). It was hypothesized that LVF presentations of rotated letters would have a greater apparent duration . This was based on Hock, Kronseder, and Corcoran's (1975) demonstration that rotated letters presented in the LVF produce longer reaction times than RVF presentations on a visual comparisons task. The results were that subjects' "left" vs. "right" responses did not differ significantly for any of the conditions. Methodological considerations were cited as a possible reason for the failure to confirm the present hypo thesis.
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Date Issued: 1976
PURL: http://purl.flvc.org/fcla/dt/13810
Subject Headings: Time perception, Visual perception, Human information processing
Format: Document (PDF)

Title: THE PERCEPTION OF DISTANCE AND ANGLE RELATIONS FOR SIMPLE DOT PATTERNS.
Creator: O'ROURKE, GERALD., Florida Atlantic University
Abstract/Description: This research was concerned with the perception of inter-element distance and angle relations for pairs of dots arranged vertically, horizontally, oblique-left, and oblique-right. For each trial, a pair of dots was presented in different global locations, for five consecutive frames. The subject's task was to detect a change in the relative location of the dots, which could occur during one of the five frames. Each subject participated in three different conditions. One condition emphasized...
Show moreThis research was concerned with the perception of inter-element distance and angle relations for pairs of dots arranged vertically, horizontally, oblique-left, and oblique-right. For each trial, a pair of dots was presented in different global locations, for five consecutive frames. The subject's task was to detect a change in the relative location of the dots, which could occur during one of the five frames. Each subject participated in three different conditions. One condition emphasized the detection of changes in distance between the elements; the second emphasized the detection of changes in the angle formed by the elements. The third condition did not focus attention on either distance or angle changes. Results indicated that focussing attention on either distance or angle changes affected sensitivity to distance changes for rectilinear, but not for oblique arrangements. These results suggested that the vertical and horizontal components of Inter-element distance are perceptually fundamental, and that the Euclidean distance between two elements and the angle formed by the elements are internally computed from the perceptually fundamental distance components.
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Date Issued: 1986
PURL: http://purl.flvc.org/fcla/dt/14288
Subject Headings: 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: 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)

Title: Visual threat cues for autonomous navigation.
Creator: Kundur, Sridhar Reddy, Florida Atlantic University, Raviv, Daniel, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: This dissertation deals with novel vision-based motion cues called the Visual Threat Cues (VTCs), suitable for autonomous navigation tasks such as collision avoidance and maintenance of clearance. The VTCs are time-based and provide some measure for a relative change in range as well as clearance between a 3D surface and a moving observer. They are independent of the 3D environment around the observer and need almost no a-priori knowledge about it. For each VTC presented in this dissertation,...
Show moreThis dissertation deals with novel vision-based motion cues called the Visual Threat Cues (VTCs), suitable for autonomous navigation tasks such as collision avoidance and maintenance of clearance. The VTCs are time-based and provide some measure for a relative change in range as well as clearance between a 3D surface and a moving observer. They are independent of the 3D environment around the observer and need almost no a-priori knowledge about it. For each VTC presented in this dissertation, there is a corresponding visual field associated with it. Each visual field constitutes a family of imaginary 3D surfaces attached to the moving observer. All the points that lie on a particular imaginary 3D surface, produce the same value of the VTC. These visual fields can be used to demarcate the space around the moving observer into safe and danger zones of varying degree. Several approaches to extract the VTCs from a sequence of monocular images have been suggested. A practical method to extract the VTCs from a sequence of images of 3D textured surfaces, obtained by a visually fixation, fixed-focus moving camera is also presented. This approach is based on the extraction of a global image dissimilarity measure called the Image Quality Measure (IQM), which is extracted directly from the raw data of the gray level images. Based on the relative variations of the measured IQM, the VTCs are extracted. This practical approach to extract the VTCs needs no 3D reconstruction, depth information, optical flow or feature tracking. This algorithm to extract the VTCs was tested on several indoor as well as outdoor real image sequences. Two vision-based closed-loop control schemes for autonomous navigation tasks were implemented in a-priori unknown textured environments using one of the VTCs as relevant sensory feedback information. They are based on a set of IF-THEN fuzzy rules and need almost no a-priori information about the vehicle dynamics, speed, direction of motion, etc. They were implemented in real-time using a camera mounted on a six degree-of-freedom flight simulator.
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Date Issued: 1996
PURL: http://purl.flvc.org/fcla/dt/12476
Subject Headings: Computer vision, Robot vision, Visual perception
Format: Document (PDF)

Title: The effects of standard and deviant tones on event-related brain potentials and reaction-times to visual stimuli.
Creator: Fernandez, Mercedes, Florida Atlantic University, Nash, Allan J.
Abstract/Description: This research investigated whether choice reaction time (RT) measures and the P300 component of the event-related brain potential (ERP) could be employed to index the attentional resources associated with performing two near-simultaneous tasks. Specifically, this study investigated the effects of auditory tones on the ERPs and RTs associated with a visual stimulus when the stimuli in both modalities were presented in close temporal proximity. The hypothesis that the ERPs and RTs elicited by...
Show moreThis research investigated whether choice reaction time (RT) measures and the P300 component of the event-related brain potential (ERP) could be employed to index the attentional resources associated with performing two near-simultaneous tasks. Specifically, this study investigated the effects of auditory tones on the ERPs and RTs associated with a visual stimulus when the stimuli in both modalities were presented in close temporal proximity. The hypothesis that the ERPs and RTs elicited by the deviant visual stimulus would index the processing demands associated with the auditory modality was confirmed. In general, greater P300 amplitude associated with one task indicates diminished P300 and poorer performance on a second task. The results indicate that P300 may be a sensitive indicator of shared processing resources when two tasks are performed near simultaneously.
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Date Issued: 1995
PURL: http://purl.flvc.org/fcla/dt/15122
Subject Headings: Selectivity (Psychology), Evoked potentials (Electrophysiology), Visual perception, Signal detection (Psychology)
Format: Document (PDF)

Motion perception (Vision) (6)	+ -
Human information processing (3)	+ -
Optical pattern recognition (3)	+ -
Perceptual motor processes (3)	+ -
Recognition (Psychology) (3)	+ -

Binocular rivalry (2)	+ -
Context effects (Psychology) (2)	+ -
Electroencephalography (2)	+ -
Pattern recognition systems (2)	+ -
Selectivity (Psychology) (2)	+ -
Space perception (2)	+ -
Visual pathways (2)	+ -
Advanced information processing (1)	+ -
Attention (1)	+ -
Binocular vision (1)	+ -
Collision avoidance systems (1)	+ -
Computer algorithms (1)	+ -
Computer vision (1)	+ -
Contrast sensitivity (Vision) (1)	+ -
Cues (1)	+ -
Data compression (Computer science) (1)	+ -
Digital video (1)	+ -
Discourse analysis (1)	+ -
Evoked potentials (Electrophysiology) (1)	+ -
Eye -- Movements (1)	+ -
Eye tracking (1)	+ -
Eye--Movements (1)	+ -
Eyewitness identification (1)	+ -
Figure-ground perception (1)	+ -

Charles E. Schmidt College of Science (11)	+ -
Department of Psychology (10)	+ -
College of Engineering and Computer Science (6)	+ -
Department of Computer and Electrical Engineering and Computer Science (6)	+ -
Barenholtz, Elan (5)	+ -

Hock, Howard S. (5)	+ -
Raviv, Daniel (4)	+ -
Hong, Sang Wook (3)	+ -
Cox, Dustin (2)	+ -
Balz, Gunther William (1)	+ -
Center for Complex Systems and Brain Sciences (1)	+ -
Chilamakuri, Pavani. (1)	+ -
College for Design and Social Inquiry (1)	+ -
Eastman, Kathleen E. (1)	+ -
Ester, Edward (1)	+ -
Fernandez, Mercedes (1)	+ -
Furht, Borko (1)	+ -
GOLD, LEON SAMUEL (1)	+ -
GORDON, GREGORY PETER (1)	+ -
Glenn, William E. (1)	+ -
Huisman, Avia (1)	+ -
Kersten, Alan (1)	+ -
Kleiman, Michael J. (1)	+ -
Kogan, Kristine Marie (1)	+ -
Kundur, Sridhar Reddy (1)	+ -
MILLER, JANE TURTON. (1)	+ -
MURPHY, ARTHUR LORD (1)	+ -
Miller, Hugh T. (1)	+ -
Nash, Allan J. (1)	+ -

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