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- Title
- 2012-2013 Program Review Complex Systems.
- Creator
- Florida Atlantic University, Center for Complex Systems and Brain Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Florida Atlantic University Departmental Dashboard Indicators. Department program reviews for Charles E. Schmidt College of Science, Florida Atlantic University.
- Date Issued
- 2012-2013
- PURL
- http://purl.flvc.org/fau/fd/FA00007688
- Format
- Document (PDF)
- Title
- 2010-2011 Program Review Complex Systems.
- Creator
- Florida Atlantic University, Center for Complex Systems and Brain Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Florida Atlantic University Departmental Dashboard Indicators. Department program reviews for Charles E. Schmidt College of Science, Florida Atlantic University.
- Date Issued
- 2010-2011
- PURL
- http://purl.flvc.org/fau/fd/FA00007681
- Format
- Document (PDF)
- Title
- 2014-2015 Program Review Complex Systems.
- Creator
- Florida Atlantic University, Center for Complex Systems and Brain Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Florida Atlantic University Departmental Dashboard Indicators. Department program reviews for Charles E. Schmidt College of Science, Florida Atlantic University.
- Date Issued
- 2014-2015
- PURL
- http://purl.flvc.org/fau/fd/FA00007702
- Format
- Document (PDF)
- Title
- 2013-2014 Program Review Complex Systems.
- Creator
- Florida Atlantic University, Center for Complex Systems and Brain Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Florida Atlantic University Departmental Dashboard Indicators. Department program reviews for Charles E. Schmidt College of Science, Florida Atlantic University.
- Date Issued
- 2013-2014
- PURL
- http://purl.flvc.org/fau/fd/FA00007695
- Format
- Document (PDF)
- Title
- 2015-2016 Program Review Complex Systems.
- Creator
- Florida Atlantic University, Center for Complex Systems and Brain Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Florida Atlantic University Departmental Dashboard Indicators. Department program reviews for Charles E. Schmidt College of Science, Florida Atlantic University.
- Date Issued
- 2015-2016
- PURL
- http://purl.flvc.org/fau/fd/FA00007709
- Format
- Document (PDF)
- Title
- 2009-2010 Program Review Complex Systems.
- Creator
- Florida Atlantic University, Center for Complex Systems and Brain Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Florida Atlantic University Departmental Dashboard Indicators. Department program reviews for Charles E. Schmidt College of Science, Florida Atlantic University.
- Date Issued
- 2009-2010
- PURL
- http://purl.flvc.org/fau/fd/FA00007674
- Format
- Document (PDF)
- Title
- 2016-2017 Program Review Complex Systems.
- Creator
- Florida Atlantic University, Center for Complex Systems and Brain Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Florida Atlantic University Departmental Dashboard Indicators. Department program reviews for Charles E. Schmidt College of Science, Florida Atlantic University.
- Date Issued
- 2016-2017
- PURL
- http://purl.flvc.org/fau/fd/FA00007716
- Format
- Document (PDF)
- Title
- Attentional and affective responses to complex musical rhythms.
- Creator
- Chapin, Heather L., Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
- Abstract/Description
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I investigated how two types of rhythmic complexity, syncopation and tempo fluctuation, affect the neural and behavioral responses of listeners. The aim of Experiment 1 was to explore the role of attention in pulse and meter perception using complex rhythms. A selective attention paradigm was used in which participants attended either to a complex auditory rhythm or a visually presented list of words. Performance on a reproduction task was used to gauge whether participants were attending to...
Show moreI investigated how two types of rhythmic complexity, syncopation and tempo fluctuation, affect the neural and behavioral responses of listeners. The aim of Experiment 1 was to explore the role of attention in pulse and meter perception using complex rhythms. A selective attention paradigm was used in which participants attended either to a complex auditory rhythm or a visually presented list of words. Performance on a reproduction task was used to gauge whether participants were attending to the appropriate stimulus. Selective attention to rhythms led to increased BOLD (Blood Oxygen Level-Dependent) responses in basal ganglia, and basal ganglia activity was observed only after the rhythms had cycled enough times for a stable pulse percept to develop. These observations show that attention is needed to recruit motor activations associated with the perception of pulse in complex rhythms. Moreover, attention to the auditory stimulus enhanced activity in an attentional sensory network including primary auditory, insula, anterior cingulate, and prefrontal cortex, and suppressed activity in sensory areas associated with attending to the visual stimulus. In Experiment 2, the effect of tempo fluctuation in expressive music on emotional responding in musically experienced and inexperienced listeners was investigated. Participants listened to a skilled music performance, including natural fluctuations in timing and sound intensity that musicians use to evoke emotional responses, and a mechanical performance of the same piece, that served as a control. Participants reported emotional responses on a 2-dimensional rating scale (arousal and valence), before and after fMRI scanning. During fMRI scanning, participants listened without reporting emotional responses. Tempo fluctuations predicted emotional arousal ratings for all listeners., Expressive performance was associated with BOLD increases in limbic areas for all listeners and in limbic and reward related areas forthose with musical experience. Activity in the dorsal anterior cingulate, which may reflect temporal expectancy, was also dependent on the musical experience of the listener. Changes in tempo correlated with activity in a mirror neuron network in all listeners, and mirror neuron activity was associated with emotional arousal in experienced listeners. These results suggest that emotional responding to music occurs through an empathic motor resonance.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/368606
- Subject Headings
- Perceptual-motor learning, Musical perception, Computational neuroscience, Emotions in music, Music, Psychological aspects
- Format
- Document (PDF)
- Title
- Brain dynamics and behavioral basis of a higher level cognitive task: number comparison.
- Creator
- Ballan, Meltem., Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
- Abstract/Description
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Number perception, its neural basis and its relationship to how numerical stimuli are presented have been challenging research topics in cognitive neuroscience for many years. A primary question that has been addressed is whether the perception of the quantity of a visually presented number stimulus is dissociable from its early visual perception. The present study examined the possible influence of visual quality judgment on quantity judgments of numbers. To address this issue, volunteer...
Show moreNumber perception, its neural basis and its relationship to how numerical stimuli are presented have been challenging research topics in cognitive neuroscience for many years. A primary question that has been addressed is whether the perception of the quantity of a visually presented number stimulus is dissociable from its early visual perception. The present study examined the possible influence of visual quality judgment on quantity judgments of numbers. To address this issue, volunteer adult subjects performed a mental number comparison task in which two-digit stimulus numbers (Arabic number format), among the numbers between 31 and 99 were mentally compared to a memorized reference number, 65. Reaction times (RTs) and neurophysiological (i.e. electroencephalographic (EEG) data) responses were acquired simultaneously during performance of the two-digit number comparison task. In this particular quantity comparison task, the number stimuli were classified into three distance factors. That is, numbers were a close, medium or far distance from the reference number (i.e., 65). In order to evaluate the relationship between numerical stimulus quantity and quality, the number stimuli were embedded in varying degrees of a typical visual noise form, known as "salt and pepper noise" (e.g., the visual noise one perceives when viewing a photograph taken with a dusty camera lens). In this manner, the visual noise permitted visual quality to be manipulated across three levels: no noise, medium noise (approximately 60% degraded visual quality from nonoise), and dense noise (75% degraded visual quality from no-noise)., The RTs provided the information about the overt responses; however, the temporal relationship of visual quality (starts earlier than quantity perception) and quantity were examined using eventrelated potentials (ERPs) extracted from continuous EEG recordings. The analysis of the RTs revealed that the judgment of number quantity is dependent upon visual number quality. In addition, the same effect was observed over the ERP components occurring between 100 ms and 300 ms after stimulus onset time over the posterior electrodes. Principal components analysis (PCA) and independent component analysis (ICA) methods were used to further analyze the ERP data. The consistent results of the PCA and ICA were used to represent the spatial brain dynamics, as well as to obtain temporal dynamics. The overall conclusion of the present study is that ERPs, ICs and PCs along with RTs suggested a strategy of quantitative perception (i.e., number comparison) based on the qualitative attributes of the stimuli highlighting the importance of the design of the task and the methodology
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2867328
- Subject Headings
- Cognitive neuroscience, Learning, Physiological aspects, Visual perception, Information visualization, Mathematics, Philosophy
- Format
- Document (PDF)
- Title
- Face processing in persons with and without Alzheimer's disease.
- Creator
- Winchester, Jeanna., Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
- Abstract/Description
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This study aimed to understand the differences in strength or coordination of brain regions involved in processing faces in the presence of aging and/or progressing neuropathology (Alzheimer's disease). To this end, Experiment 1 evaluated age-related differences in basic face processing and the effects of familiarity in face processing. Overall, face processing in younger (22-35yrs) and older participants (63-83yrs) recruited a broadly distributed network of brain activity, but the...
Show moreThis study aimed to understand the differences in strength or coordination of brain regions involved in processing faces in the presence of aging and/or progressing neuropathology (Alzheimer's disease). To this end, Experiment 1 evaluated age-related differences in basic face processing and the effects of familiarity in face processing. Overall, face processing in younger (22-35yrs) and older participants (63-83yrs) recruited a broadly distributed network of brain activity, but the distribution of activity varied depending on the age of the individual. The younger population utilized regions of the occipitotemporal, medial frontal and posterior parietal cortices while the older population recruited a concentrated occipitotemporal network. The younger participants were also sensitive to the type of face presented, as Novel faces were associated with greater mean BOLD activity than either the Famous or Relatives faces. Interestingly, Relatives faces were associated with greater mean B OLD activity in more regions of the brain than found in any other analysis in Exp. 1, spanning the inferior frontal, medial temporal and inferior parietal cortices. In contrast, the older adults were not sensitive to the type of face presented, which could reflect a difference in cognitive strategies used by the older population when presented with this type of face stimuli. Experiment 2 evaluated face processing, familiarity in face processing and also emphasized the interactive roles autobiographical processing and memory recency play in processing familiar faces in mature adults (MA; 45-55yrs), older adults (OA; 70-92yrs) and patients suffering from Alzheimer's disease (AD; 70-92yrs)., MA participants had greater mean BOLD activity values in more regions of the brain than observed in either of the older adult populations, spanning regions of the medial frontal, medial temporal, inferior parietal and occipital cortices. OA, in contrast, utilized a concentrated frontal and medial temporal network and AD participants had the greatest deficit in BOLD activity overall.Age-related differences in processing faces, in processing the type of face presented, in autobiographical information processing and in processing the recency of a memory were noted, as well as differences due to the deleterious effects of AD.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/199330
- Subject Headings
- Face perception, Cognition, Age factors, Human face recognition, Alzheimer's disease, Facial expression, Physiological aspects
- Format
- Document (PDF)
- Title
- Functional consequences of top-down anticipatory modulation of primary visual cortex.
- Creator
- Richter, Craig G., Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
- Abstract/Description
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It is well established that anticipation of the arrival of an expected stimulus is accompanied by rich ongoing oscillatory neurodynamics, which span and link large areas of cortex. An intriguing possibility is that these dynamic interactions may convey knowledge that is embodied by large-scale neurocognitive networks from higher level regions of multi-model cortex to lower level primary sensory areas. In the current study, using autoregressive spectral analysis, we establish that during the...
Show moreIt is well established that anticipation of the arrival of an expected stimulus is accompanied by rich ongoing oscillatory neurodynamics, which span and link large areas of cortex. An intriguing possibility is that these dynamic interactions may convey knowledge that is embodied by large-scale neurocognitive networks from higher level regions of multi-model cortex to lower level primary sensory areas. In the current study, using autoregressive spectral analysis, we establish that during the anticipatory phase of a visual discrimination task there are rich patterns of coherent interaction between various levels of the ventral visual hierarchy across the frequency spectrum of 8 - 90 Hz. Using spectral Granger causality we determined that a subset of these interactions carry beta frequency (14 - 30 Hz) top-down influences from higher level visual regions V4 and TEO to primary visual cortex. We investigated the functional significance of these top-down interactions by correlating the magnitude of the anticipatory signals with the amplitude of the visual evoked potential that was elicited by stimulus processing. We found that in one third of the extrastriate-striate pairs, tested in three monkeys, the amplitude of the visual evoked response is well predicted by the magnitude of pre-stimulus coherent top-down anticipatory influences. To investigate the dynamics of the coherent and topdown Granger causal interactions, we analyzed the relationship between coherence and top-down Granger causality with stimulus onset asynchrony. This analysis revealed that in an abundance of cases the magnitudes of the coherent interactions and top-down directional influences scaled with the length of time that had elapsed before stimulus onset., Together these results reveal a complex network of coherent and top-down directional interactions that predict the amplitude of early components of the visual evoked potential in primary visual cortex and vary in strength on the basis of the length of the stimulus onset.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/369200
- Subject Headings
- Cognitive neuroscience, Brain mapping, Visual perception, Testing, Intersensory effects
- Format
- Document (PDF)
- Title
- 1/f structure of temporal fluctuation in rhythm performance and rhythmic coordination.
- Creator
- Rankin, Summer K., Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
- Abstract/Description
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This dissertation investigated the nature of pulse in the tempo fluctuation of music performance and how people entrain with these performed musical rhythms. In Experiment 1, one skilled pianist performed four compositions with natural tempo fluctuation. The changes in tempo showed long-range correlation and fractal (1/f) scaling for all four performances. To determine whether the finding of 1/f structure would generalize to other pianists, musical styles, and performance practices, fractal...
Show moreThis dissertation investigated the nature of pulse in the tempo fluctuation of music performance and how people entrain with these performed musical rhythms. In Experiment 1, one skilled pianist performed four compositions with natural tempo fluctuation. The changes in tempo showed long-range correlation and fractal (1/f) scaling for all four performances. To determine whether the finding of 1/f structure would generalize to other pianists, musical styles, and performance practices, fractal analyses were conducted on a large database of piano performances in Experiment 3. Analyses revealed signicant long-range serial correlations in 96% of the performances. Analysis showed that the degree of fractal structure depended on piece, suggesting that there is something in the composition's musical structure which causes pianists' tempo fluctuations to have a similar degree of fractal structure. Thus, musical tempo fluctuations exhibit long-range correlations and fractal scaling. To examine how people entrain to these temporal fluctuations, a series of behavioral experiments were conducted where subjects were asked to tap the pulse (beat) to temporally fluctuating stimuli. The stimuli for Experiment 2 were musical performances from Experiment 1, with mechanical versions serving as controls. Subjects entrained to all stimuli at two metrical levels, and predicted the tempo fluctuations observed in Experiment 1. Fractal analyses showed that the fractal structure of the stimuli was reected in the inter-tap intervals, suggesting a possible relationship between fractal tempo scaling, pulse perception, and entrainment. Experiments 4-7 investigated the extent to which people use long-range correlation and fractal scaling to predict tempo fluctuations in fluctuating rhythmic sequences., Both natural and synthetic long-range correlations enabled prediction, as well as shuffled versions which contained no long-term fluctuations. Fractal structure of the stimuli was again in the inter-tap intervals, with persistence for the fractal stimuli, and antipersistence for the shuffled stimuli. 1/f temporal structure is suficient though not necessary for prediction of fluctuations in a stimulus with large temporal fluctuations.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2705083
- Subject Headings
- Music, Psychological aspects, Emotions in music, Perceptual-motor learning, Computational neuroscience, Synchronization, Musical perception
- Format
- Document (PDF)
- Title
- The neural correlates of endogenously cued covert visuospatial attentional shifting in the cue-target interval: an electroencephalographic study.
- Creator
- Modestino, Edward Justin., Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
- Abstract/Description
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This study investigated electroencephalographic differences related to cue (central left- or right-directed arrows) in a covert endogenous visual spatial attention task patterned after that of Hopf and Mangun (2000). This was done with the intent of defining the timing of components in relation to cognitive processes within the cue-target interval. Multiple techniques were employed to do this. Event-related potentials (ERPs) were examined using Independent Component Analysis. This revealed a...
Show moreThis study investigated electroencephalographic differences related to cue (central left- or right-directed arrows) in a covert endogenous visual spatial attention task patterned after that of Hopf and Mangun (2000). This was done with the intent of defining the timing of components in relation to cognitive processes within the cue-target interval. Multiple techniques were employed to do this. Event-related potentials (ERPs) were examined using Independent Component Analysis. This revealed a significant N1, between 100:200 ms post-cue, greater contralateral to the cue. Difference wave ERPs, left minus right cue-locked data, divulged significant early directing attention negativity (EDAN) at 200:400 ms post-cue in the right posterior which reversed polarity in the left posterior. Temporal spectral evolution (TSE) analysis of the alpha band revealed three stages, (1) high bilateral alpha precue to 120 ms post-cue, (2) an event related desynchronization (ERD) from approximately 120 ms: 500 ms post-cue, and (3) an event related synchronization (ERS) rebound, 500: 900 ms post-cue, where alpha amplitude, a measure of activity, was highest contralateral to the ignored hemifield and lower contralateral to the attended hemifield. Using a combination of all of these components and scientific literature in this field, it is possible to plot out the time course of the cognitive events and their neural correlates.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/369199
- Subject Headings
- Brain mapping, Neural networks (Neurobiology), Cognitive neuroscience, Recognition (Psychology), Cognition, Research, Methodology
- Format
- Document (PDF)
- Title
- Investigation of human visual spatial attention with fMRI and Granger Causality analysis.
- Creator
- Tang, Wei, Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
- Abstract/Description
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Contemporary understanding of human visual spatial attention rests on the hypothesis of a top-down control sending from cortical regions carrying higher-level functions to sensory regions. Evidence has been gathered through functional Magnetic Resonance Imaging (fMRI) experiments. The Frontal Eye Field (FEF) and IntraParietal Sulcus (IPS) are candidates proposed to form the frontoparietal attention network for top-down control. In this work we examined the influence patterns between...
Show moreContemporary understanding of human visual spatial attention rests on the hypothesis of a top-down control sending from cortical regions carrying higher-level functions to sensory regions. Evidence has been gathered through functional Magnetic Resonance Imaging (fMRI) experiments. The Frontal Eye Field (FEF) and IntraParietal Sulcus (IPS) are candidates proposed to form the frontoparietal attention network for top-down control. In this work we examined the influence patterns between frontoparietal network and Visual Occipital Cortex (VOC) using a statistical measure, Granger Causality (GC), with fMRI data acquired from subjects participated in a covert attention task. We found a directional asymmetry in GC between FEF/IPS and VOC, and further identified retinotopically specific control patterns in top-down GC. This work may lead to deeper understanding of goal-directed attention, as well as the application of GC to analyzing higher-level cognitive functions in healthy functioning human brain.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3334101
- Subject Headings
- Attention, Physiological aspects, Cognitive neuroscience, Brain, Magnetic resonance imaging, Sensorimotor integration, Movement sequences, Human information processing, Cognitive psychology, Visual perception, Testing
- Format
- Document (PDF)
- Title
- Hypoxia-regulated gene therapy for the treatment of subretinal neovascularization in age-related macular degeneration.
- Creator
- Smith, George Wesley Tyler., Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
- Abstract/Description
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Age-related macular degeneration (AMD) is the leading cause of blindness in the western world for people over 60 years of age. The most severe pathological event of AMD is choroidal neovascularization (CNV), the process of new vessel formation emerging from the choroid. The new vessels extend into the normally avascular photoreceptor cell layer, where they leak fluid and cause photoreceptor cell death. CNV is thought to be initiated by hypoxia and chronic inflammation, which occur due to...
Show moreAge-related macular degeneration (AMD) is the leading cause of blindness in the western world for people over 60 years of age. The most severe pathological event of AMD is choroidal neovascularization (CNV), the process of new vessel formation emerging from the choroid. The new vessels extend into the normally avascular photoreceptor cell layer, where they leak fluid and cause photoreceptor cell death. CNV is thought to be initiated by hypoxia and chronic inflammation, which occur due to abnormal, age-related changes within the retinal pigmented epithelium (RPE). These events cause increased expression of the angiogenic protein vascular endothelial growth factor (VEGF) via hypoxiainducible factor-1 (HIF-1), a transcription factor that is vital in regulation of cellular responses to hypoxic and inflammatory conditions. Increased VEGF signaling stimulates proliferation and migration of vascular endothelial cells and facilitates the neovascular process. To target the early pathological events that lead to CNV, we have engineered a novel gene therapy vector that uses HIF-1 regulation to stimulate production of an angiostatic protein, endostatin from the RPE. The purpose of this study was to characterize the activity of our hypoxiaregulated, RPE-specific promoter in vitro, and investigate the effects of regulated endostatin expression, driven by our regulated promoter, on CNV in a mousemodel. We found the regulated promoter construct has robust activity in vitro only in RPE cells, and is conditionally responsive in hypoxic conditions., In the laserinduced CNV model, CNV area was 80% smaller (P<0.0001) in eyes treated with the hypoxia-regulated, RPE-specific endostatin vector than in untreated eyes. CNV area was equally reduced in eyes treated with an unregulated endostatin vector (CMV-endostatin). However, less endostatin protein was detected in eyes treated with the regulated vector. Since it is unknown whether broad and constitutive endostatin expression will have damaging effects within the retina, it may be safer to limit its expression to pathological conditions. We have demonstrated that local, hypoxia-regulated expression of endostatin can effectively inhibit CNV, and thus, offers the further possibility of a prophylactic treatment for neovascular AMD.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2979379
- Subject Headings
- Retinal degeneration, Treatment, Eye, Aging, Neovascularization inhibitors
- Format
- Document (PDF)
- Title
- Hypoxia-regulated glial cell-specific gene therapy to treat retinal neovascularization.
- Creator
- Biswal, Manas Ranjan., Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
- Abstract/Description
-
Diabetic retinopathy is an ischemic retinal neovascular disease causing vision loss among adults. The studies presented involve the design and testing of a gene therapy vector to inhibit retinal revascularization, similar to that found in diabetic retinopathy. Gene therapy has proven to be an effective method to introduce therapeutic proteins to treat retinal diseases. Targeting a specific cell type and expression of therapeutic proteins according to the tissue microenvironment should have an...
Show moreDiabetic retinopathy is an ischemic retinal neovascular disease causing vision loss among adults. The studies presented involve the design and testing of a gene therapy vector to inhibit retinal revascularization, similar to that found in diabetic retinopathy. Gene therapy has proven to be an effective method to introduce therapeutic proteins to treat retinal diseases. Targeting a specific cell type and expression of therapeutic proteins according to the tissue microenvironment should have an advantage over traditional gene therapy by avoiding unwanted transgene expression. Hypoxia plays a significant role in the pathophysiology of many retinal ischemic diseases. Retinal Mèuller cells provide structural and functional support to retinal neurons, as well as playing a significant role in retinal neovascularization. Targeting Mèuller cells may be an effective strategy to prevent retinal neovascularization under pathological conditions. ... The hypoxia regulated, glial specific vector successfully reduced the abnormal neovascularization in the periphery by 93% and reduced the central vasobliterated area by 90%. A substantial amount of exogenous endostatin was produced in the retinas of P17 OIR mice. A significant increase in human endostatin protein and reduced vascular endothelial growth factor (VEGF) were identified by Western blot and ELISA, respectively. These findings suggest hypoxia-regulated, glial cell-specific scAAV mediated gene expression may be useful to prevent blindness found in devastating retinal diseases involving neovascularization.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3359290
- Subject Headings
- Diabetic retinopathy, Research, Methodology, Gene therapy, Retinal degeneration, Treatment, Neovascularization inhibitors, Mitochondrial pathology, Retina, Cytology, Gene mapping
- Format
- Document (PDF)
- Title
- Spatiotemporal beanformer analysis of neuromagnetic activity in sensorimotor cortex: rhythmic perception, production and sensorimotor coordination.
- Creator
- Ferrari, Paul., Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
- Abstract/Description
-
Research presented in this dissertation has the central aim of applying a novel method of source localization called beamforming to neuromagnetic recordings for characterizing dynamic spatiotemporal activity of sensorimotor brain processes in subjects during rhythmic auditory stimulation, self-paced movement, and two sensorimotor coordination (synchronization and syncopation) tasks known to differentiate on the basis of behavioral stability. Each experimental condition was performed at...
Show moreResearch presented in this dissertation has the central aim of applying a novel method of source localization called beamforming to neuromagnetic recordings for characterizing dynamic spatiotemporal activity of sensorimotor brain processes in subjects during rhythmic auditory stimulation, self-paced movement, and two sensorimotor coordination (synchronization and syncopation) tasks known to differentiate on the basis of behavioral stability. Each experimental condition was performed at different rates resulting in 26 experimental runs per subject. Event-related neural responses were recorded with a whole-head MEG system and characterized in terms of their phase-locked (evoked) and non-phase-locked (induced) activity within the brain using both whole-brain analysis and region of interest (ROI) analysis. The analysis of the auditory conditions revealed that neural activity within extraauditory areas throughout the brain, including sensorimotor cortex, is modulated by rhythmic auditory stimulation. Additionally, the temporal profile of this activity was markedly different between sensorimotor and auditory cortex, possibly revealing different physiological processes, entrained within a common network for representing isochronic auditory events. During self-paced movements cycle-by-cycle dynamics of induced neural activity was measured and consistent neuro-modulation in the form of event-related desynchronization (ERD) and synchronization (ERS) was observed at all rates investigated (0.25 - 1.75Hz). ERD and ERS modulations exhibited dynamic scaling properties on a cycle-by-cycle basis that depended on the period of movement. Activity in the beta- and mu-bands also exhibited patterns of phase locking between sensorimotor locations. Phase locking patterns exhibited abrupt decreases with increases in movement rate., During sensorimotor coordination tasks, the effect of temporal positioning of the auditory stimulus was apparent within sensorimotor cortical sites. This finding offers direct source level support for previous sensor level analysis revealing a differentiation of functional specificity for mu- and beta-band activity (Chen, Ding, Kelso, 2003; Jantzen, Fuchs, Mayville et al., 2001; Mayville, Fuchs, Ding et al., 2001), and may be reflective of specific coupling mechanisms between auditory and sensorimotor networks. The beamformer analysis applied within this dissertation successfully characterized large-scale neural networks during a variety of rhythmic perceptual, motor, and sensorimotor tasks resulting in the general message that information processes across disparate parts of the brain from different sensory, motor, and cognitive modalities appear to have the ability for widespread integration.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/228770
- Subject Headings
- Sensorimotor integration, Perceptual-motor processes, Auditory provoked response, Brain mapping
- Format
- Document (PDF)
- Title
- Spatiotemporal brain dynamics of the resting state.
- Creator
- Rho, Young-Ah., Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
- Abstract/Description
-
Traditionally brain function is studied through measuring physiological responses in controlled sensory, motor, and cognitive paradigms. However, even at rest, in the absence of overt goal-directed behavior, collections of cortical regions consistently show temporally coherent activity. In humans, these resting state networks have been shown to greatly overlap with functional architectures present during consciously directed activity, which motivates the interpretation of rest activity as day...
Show moreTraditionally brain function is studied through measuring physiological responses in controlled sensory, motor, and cognitive paradigms. However, even at rest, in the absence of overt goal-directed behavior, collections of cortical regions consistently show temporally coherent activity. In humans, these resting state networks have been shown to greatly overlap with functional architectures present during consciously directed activity, which motivates the interpretation of rest activity as day dreaming, free association, stream of consciousness, and inner rehearsal. In monkeys, it has been shown though that similar coherent fluctuations are present during deep anesthesia when there is no consciousness. These coherent fluctuations have also been characterized on multiple temporal scales ranging from the fast frequency regimes, 1-100 Hz, commonly observed in EEG and MEG recordings, to the ultra-slow regimes, < 0.1 Hz, observed in the Blood Oxygen Level Dependent (BOLD) signal of functi onal magnetic resonance imaging (fMRI). However, the mechanism for their genesis and the origin of the ultra-slow frequency oscillations has not been well understood. Here, we show that comparable resting state networks emerge from a stability analysis of the network dynamics using biologically realistic primate brain connectivity, although anatomical information alone does not identify the network. We specifically demonstrate that noise and time delays via propagation along connecting fibres are essential for the emergence of the coherent fluctuations of the default network. The combination of anatomical structure and time delays creates a spacetime structure in which the neural noise enables the brain to explore various functional configurations representing its dynamic repertoire., Using a simplified network model comprised of 3 nodes governed by the dynamics of FitzHugh-Nagumo (FHN) oscillators, we systematically study the role of time delay and coupling strength in the Using a simplified network model comprised of 3 nodes governed by the dynamics of FitzHugh-Nagumo (FHN) oscillators, we systematically study the role of time delay and coupling strength in the generation o f the slow coherent fluctuations. We find that these fluctuations in the BOLD signal are significantly correlated with the level of neural synchrony implicating that transient interareal synchronizations are the mechanism causing the emergence of the ultra slow coherent fluctuations in the BOLD signal.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/367762
- Subject Headings
- Brain mapping, Sensorimotor integration, Perceptual-motor processes, Intersensory effects, Movement sequences
- Format
- Document (PDF)
- Title
- Mathematical model of the dynamics of psychotherapy.
- Creator
- Norman, Michael D., Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
- Abstract/Description
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This is a novel attempt to produce a rigorous mathematical model of a complex system. The complex system under study is the relationship between therapists and their clients. The success of psychotherapy depends on the nature of the relationship between a therapist and a client. We use dynamical systems theory to model the dynamics of the emotional interaction between a therapist and client. We determine how the therapeutic endpoint and the dynamics of getting there depend on the parameters...
Show moreThis is a novel attempt to produce a rigorous mathematical model of a complex system. The complex system under study is the relationship between therapists and their clients. The success of psychotherapy depends on the nature of the relationship between a therapist and a client. We use dynamical systems theory to model the dynamics of the emotional interaction between a therapist and client. We determine how the therapeutic endpoint and the dynamics of getting there depend on the parameters of the model. ... We describe the emotional state of both the therapist and client with coupled, first order, nonlinear ordinary differential equations (ODE's). The rate of change of the emotional state of the therapist and client is proportional to their previous state, their uninfluenced state when alone, and an influence function which depends on the state of the other person. We formulated influence functions based on the research literature on psychotherapy and the therapeutic alliance. We then determined the critical points from the intersection of the nullclines and used a numerical ODE solver (Matlab ODE113) to compute the trajectories from different initial conditions. ... The results validate this prototypical approach to psychotherapy ; we have shown that human interaction (in the context of psychotherapy) can be quantified and modeled using differential equations.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3358758
- Subject Headings
- Psychotherapist and patient, Mathematical models, Counselor and client, Mathematical models, Therapeutic alliance, Mathematical models, Psychotherapy, Philosophy, Mathematical models, Evidence-based psychotherapy, Transference (Psychology), Countertransference (Psychology)
- Format
- Document (PDF)
- Title
- Neural and behavioral correlates of song prosody.
- Creator
- Gordon, Reyna Leigh., Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
- Abstract/Description
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This dissertation studies the neural basis of song, a universal human behavior. The relationship of words and melodies in the perception of song at phonological, semantic, melodic, and rhythmic levels of processing was investigated using the fine temporal resolution of Electroencephalography (EEG). The observations reported here may shed light on a ubiquitous human experience and also inform the discussion of whether language and music share neural resources or recruit domain-specific neural...
Show moreThis dissertation studies the neural basis of song, a universal human behavior. The relationship of words and melodies in the perception of song at phonological, semantic, melodic, and rhythmic levels of processing was investigated using the fine temporal resolution of Electroencephalography (EEG). The observations reported here may shed light on a ubiquitous human experience and also inform the discussion of whether language and music share neural resources or recruit domain-specific neural mechanisms. Experiment 1 was designed to determine whether words and melody in song are processed interactively or independently. Participants listened to sung words in which the melodies and/or the words were similar or different, and performed a same/different task while attending to the linguistic and musical dimensions in separate blocks of trials. Event-Related Potentials and behavioral data converged in showing interactive processing between the linguistic and musical dimensions of sung words, regardless of the direction of attention. In particular, the N400 component, a well-established marker of semantic processing, was modulated by musical melody. The observation that variations in musical features affect lexico-semantic processing in sung language was a novel finding with implications for shared neural resources between language and music. Experiment 2 was designed to explore the idea that well-aligned text-settings, in which the strong syllables occur on strong beats, capture listeners' attention and help them understand song lyrics. EEG was recorded while participants listened to sung sentences whose linguistic stress patterns were well-aligned, misaligned, or had variable alignment with the musical meter, and performed a lexical decision task on subsequently presented visual targets., Results showed that induced beta and evoked gamma power were modulated differently for well-aligned and misaligned syllables, and that task performance was adversely affected when visual targets followed misaligned and varied sentences. These findings suggest that alignment of linguistic stress and musical meter in song enhance beat tracking and linguistic segmentation by entraining periodic fluctuations in high frequency brain activity to the stimuli. A series of follow-up studies has been outlined to further investigate the relationship between rhythmic attending in speech and music, and the influence of metrical alignment in songs on childhood language acquisition.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2705078
- Subject Headings
- Cognitive neuroscience, Learning, Physiological aspects, Cognition in children, Physiological aspects, Prosodic analysis (Linguistics)
- Format
- Document (PDF)