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WHAT IS IMPLICIT ABOUT IMPLICIT CATEGORY LEARNING?
Title
WHAT IS IMPLICIT ABOUT IMPLICIT CATEGORY LEARNING?.
Creator
Murray, Matthew, Bohil, Corey, University of Central Florida
Abstract / Description
The conscious or unconscious acquirement of knowledge in implicit category learning was examined in accordance with predictions made by the COVIS theory of categorization (Ashby & Maddox, 2011). COVIS assumes separate category learning systems. The explicit system relies on easily verbalized rules while the implicit system requires integration of more than one stimulus dimension. Participants in this experiment categorized lines varying in length and orientation as belonging to one of two...
Show moreThe conscious or unconscious acquirement of knowledge in implicit category learning was examined in accordance with predictions made by the COVIS theory of categorization (Ashby & Maddox, 2011). COVIS assumes separate category learning systems. The explicit system relies on easily verbalized rules while the implicit system requires integration of more than one stimulus dimension. Participants in this experiment categorized lines varying in length and orientation as belonging to one of two categories; in the rule-based (RB) condition only length was relevant, while participants in the information integration (II) condition needed to integrate both dimensions. Corrective feedback was provided during training. In test phases, participants were asked to attribute their responses to one of four criteria (guess, intuition, memory, or rule), a measure adapted from Dienes and Scott (2005). Neural activity in dorsolateral prefrontal cortex (DLPFC) was recorded with a 20-optode fNIRS system. We found that in the implicit (II) learning condition, participants who reported guessing less than half the time were learning but were unconscious to the structures driving that learning, reflected by accuracy, attribution self-report and neural activation. Our results substantiate the claim that implicit category learning is mediated unconsciously and evidence the dual-system model of categorization postulated by COVIS, furthering our understanding of category learning and thus, the ways in which to improve it.
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Date Issued
2015
Identifier
CFH0004765, ucf:45348
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFH0004765
TAXING WORKING MEMORY: THE EFFECTS ON CATEGORY LEARNING
Title
TAXING WORKING MEMORY: THE EFFECTS ON CATEGORY LEARNING.
Creator
Ercolino, Ashley, Bohil, Corey, University of Central Florida
Abstract / Description
In the past decade, the COVIS model (Ashby, Alfonso-Reese, Turken, & Waldron, 1998) has emerged as the only neuropsychological theory for the existence of multiple brain systems for category learning. COVIS postulates that there are two systems, explicit and implicit, which compete against one another. These two systems reply on two discrete networks: explicit, or rule based categorization relies on executive function and working memory while implicit, or information integration...
Show moreIn the past decade, the COVIS model (Ashby, Alfonso-Reese, Turken, & Waldron, 1998) has emerged as the only neuropsychological theory for the existence of multiple brain systems for category learning. COVIS postulates that there are two systems, explicit and implicit, which compete against one another. These two systems reply on two discrete networks: explicit, or rule based categorization relies on executive function and working memory while implicit, or information integration categorization is mediated by dopaminergic pathways. The purpose of this pilot study was to further provide evidence for the existence of multiple systems of category learning. In all three experiments, we interrupted feedback processing using a modified Sternberg task. In Experiment 1 and 2, participants were separated into four conditions, rule based (RB) categorization with a short delay between feedback and the modified Sternberg task, RB categorization with a long delay, information integration (II) categorization with a short delay, and II categorization with a long delay. Participants in the RB conditions performed worse than those in the II conditions in Experiment 1 and 2. After determining there was no significant difference between the short and long delay manipulations, only the short delay was used for Experiment 3. Consistent with Experiment 1 and 2, participants in the RB condition performed worse than those in the II condition. Functional near-infrared spectroscopy (fNIRS) technology was also used in Experiment 3 to determine the difference in prefrontal activation between RB and II conditions. Although statistically not significant, across blocks, the difference in prefrontal activation increased.
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Date Issued
2015
Identifier
CFH0004870, ucf:45471
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFH0004870
EVALUATING COMPETITION BETWEEN VERBAL AND IMPLICIT SYSTEMS WITH FUNCTIONAL NEAR-INFRARED SPECTROSCOPY
Title
EVALUATING COMPETITION BETWEEN VERBAL AND IMPLICIT SYSTEMS WITH FUNCTIONAL NEAR-INFRARED SPECTROSCOPY.
Creator
Schiebel, Troy A, Bohil, Corey, University of Central Florida
Abstract / Description
In category learning, explicit processes function through the prefrontal cortex (PFC) and implicit processes function through the basal ganglia. Research suggested that these two systems compete with each other. The goal of this study was to shed light on this theory. 15 undergraduate subjects took part in an event-related experiment that required them to categorize computer-generated line-stimuli, which varied in length and/or angle depending on condition. Subjects participated in an...
Show moreIn category learning, explicit processes function through the prefrontal cortex (PFC) and implicit processes function through the basal ganglia. Research suggested that these two systems compete with each other. The goal of this study was to shed light on this theory. 15 undergraduate subjects took part in an event-related experiment that required them to categorize computer-generated line-stimuli, which varied in length and/or angle depending on condition. Subjects participated in an explicit "rule-based" (RB) condition and an implicit "information-integration" (II) condition while connected to a functional near-infrared spectroscopy (fNIRS) apparatus, which measured the hemodynamic response (HR) in their PFC. Each condition contained 2 blocks. We hypothesized that the competition between explicit and implicit systems (COVIS) would be demonstrated if, by block 2, task-accuracy was approximately equal across conditions with PFC activity being comparatively higher in the II condition. This would indicate that subjects could learn the categorization task in both conditions but were only able to decipher an explicit rule in the RB condition; their PFC would struggle to do so in the II condition, resulting in perpetually high activation. In accordance with predictions, results revealed no difference in accuracy across conditions with significant difference in channel activation. There were channel trends (p<.1) which showed PFC activation decrease in the RB condition and increase in the II condition by block 2. While these results support our predictions, they are largely nonsignificant, which could be attributed to the event-related design. Future research should utilize a larger samples size for improved statistical power.
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Date Issued
2016
Identifier
CFH2000086, ucf:45502
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFH2000086
PREDICTING COGNITIVE WORKLOAD WITH MEASURES FROM FUNCTIONAL NEAR-INFRARED SPECTROSCOPY (FNIRS) AND HEART RATE
Title
PREDICTING COGNITIVE WORKLOAD WITH MEASURES FROM FUNCTIONAL NEAR-INFRARED SPECTROSCOPY (FNIRS) AND HEART RATE.
Creator
Duany, John, Bohil, Corey, University of Central Florida
Abstract / Description
The objective of this study was to assess low to high levels of Cognitive Workload by measuring heart rate and cortical blood flow in real-time. Four conditions were implemented into a within-subjects experimental design. Two conditions of difficulty and two conditions of trial order were used to illicit different levels of workload which will be analyzed with psychophysiological equipment. Functional Near-Infrared Spectroscopy (fNIRS) has become more prominent for measuring the blood...
Show moreThe objective of this study was to assess low to high levels of Cognitive Workload by measuring heart rate and cortical blood flow in real-time. Four conditions were implemented into a within-subjects experimental design. Two conditions of difficulty and two conditions of trial order were used to illicit different levels of workload which will be analyzed with psychophysiological equipment. Functional Near-Infrared Spectroscopy (fNIRS) has become more prominent for measuring the blood oxygenation levels in the prefrontal cortex of individuals operating in hazardous work environments, students with learning disabilities, and in research for military training. This is due to the fNIR device being highly mobile, inexpensive, and able to produce a high-spatial resolution of the dorsolateral prefrontal cortex during executive functioning. Heart Rate will be measured by an Electrocardiogram, which will be used in concordance with fNIR oxygenation levels to predict if an individual is in a condition that produces low or high mental workload. Successfully utilizing heart rate and blood oxygenation data as predictors of cognitive workload may validate implementing multiple physiological devices together in real-time and may be a more accurate solution for preventing excessive workload.
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Date Issued
2013
Identifier
CFH0004478, ucf:45070
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFH0004478
NEUROIMAGING IN HUMAN CATEGORY LEARNING: A COMPARISON BETWEEN FUNCTIONAL NEAR-INFRARED SPECTROSCOPY (FNIR) AND FUNCTIONAL MAGNETIC RESONANCE IMAGING (FMRI)
Title
NEUROIMAGING IN HUMAN CATEGORY LEARNING: A COMPARISON BETWEEN FUNCTIONAL NEAR-INFRARED SPECTROSCOPY (FNIR) AND FUNCTIONAL MAGNETIC RESONANCE IMAGING (FMRI).
Creator
Viegas, Carina, Bohil, Corey, University of Central Florida
Abstract / Description
The objective of this thesis is to examine the validity of functional near-infrared spectroscopy (fNIR) to examine brain regions involved in rule based (RB) and information integration (II) category learning. We predicted similar patterns of activation found by past studies that used fMRI scans. Our goal was to test if fNIR would be able to detect changes in blood oxygenation levels of participants who learned to categorize (learners) vs. those that did not (non learners). The stimulus set...
Show moreThe objective of this thesis is to examine the validity of functional near-infrared spectroscopy (fNIR) to examine brain regions involved in rule based (RB) and information integration (II) category learning. We predicted similar patterns of activation found by past studies that used fMRI scans. Our goal was to test if fNIR would be able to detect changes in blood oxygenation levels of participants who learned to categorize (learners) vs. those that did not (non learners). The stimulus set comprised of lines that differed in length and orientation. Participants had to learn to categorize by trial and error based on the feedback provided. Behavioral and neuroimaging data was recorded for both RB and II conditions. Results showed an upward trend in response accuracy over trials for participants identified as learners. Furthermore, blood oxygenation levels reported by fNIR indicated a systematic increase in oxygen consumption for learners as compared to non learners. These areas of increased prefrontal cortex activity recorded by fNIR correspond to the same areas found to be involved in categorization by fMRI. This paper reviews the background of category learning, explores various neuroimaging techniques in categorization research, and investigates the efficacy of fNIR as a relatively new neuroimaging modality by comparing it to fMRI.
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Date Issued
2014
Identifier
CFH0004591, ucf:45231
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFH0004591
The Perceptual and Decisional Basis of Emotion Identification in Creative Writing
Title
The Perceptual and Decisional Basis of Emotion Identification in Creative Writing.
Creator
Williams, Sarah, Bohil, Corey, Hancock, Peter, Smither, Janan, Johnson, Dan, University of Central Florida
Abstract / Description
The goal of this research was to assess the ability of readers to determine the emotion of a passage of text, be it fictional or non-fictional. The research includes examining how genre (fiction and non-fiction) and emotion (positive emotion, such as happiness, and negative emotion, such as anger) interact to form a reading experience. Reading is an activity that many, if not most, humans undertake in either a professional or leisure capacity. Researchers are thus interested in the effect...
Show moreThe goal of this research was to assess the ability of readers to determine the emotion of a passage of text, be it fictional or non-fictional. The research includes examining how genre (fiction and non-fiction) and emotion (positive emotion, such as happiness, and negative emotion, such as anger) interact to form a reading experience. Reading is an activity that many, if not most, humans undertake in either a professional or leisure capacity. Researchers are thus interested in the effect reading has on the individual, particularly with regards to empathy. Some researchers believe reading fosters empathy; others think empathy might already be present in those who enjoy reading. A greater understanding of this dispute could be provided by general recognition theory (GRT). GRT allows researchers to investigate how stimulus dimensions interact in an observer's mind: on a perceptual or decisional level. In the context of reading, this allows researchers to look at how emotion is tied in with (or inseparable from) genre, or if the ability to determine the emotion of a passage is independent from the genre of the passage. In the reported studies, participants read passages and responded to questions on the passages and their content. Empathy scores significantly predicted discriminability of passage categories, as did reported hours spent reading per week. Non-fiction passages were easier to identify than fiction, and positive emotion classification was affiliated with non-fiction classification.
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Date Issued
2019
Identifier
CFE0007877, ucf:52760
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0007877
Categorical Change: Exploring the Effects of Concept Drift in Human Perceptual Category Learning
Title
Categorical Change: Exploring the Effects of Concept Drift in Human Perceptual Category Learning.
Creator
Wismer, Andrew, Bohil, Corey, Szalma, James, Neider, Mark, Gluck, Kevin, University of Central Florida
Abstract / Description
Categorization is an essential survival skill that we engage in daily. A multitude of behavioral and neuropsychological evidence support the existence of multiple learning systems involved in category learning. COmpetition between Verbal and Implicit Systems (COVIS) theory provides a neuropsychological basis for the existence of an explicit and implicit learning system involved in the learning of category rules. COVIS provides a convincing account of asymptotic performance in human category...
Show moreCategorization is an essential survival skill that we engage in daily. A multitude of behavioral and neuropsychological evidence support the existence of multiple learning systems involved in category learning. COmpetition between Verbal and Implicit Systems (COVIS) theory provides a neuropsychological basis for the existence of an explicit and implicit learning system involved in the learning of category rules. COVIS provides a convincing account of asymptotic performance in human category learning. However, COVIS (-) and virtually all current theories of category learning (-) focus solely on categories and decision environments that remain stationary over time. However, our environment is dynamic, and we often need to adapt our decision making to account for environmental or categorical changes. Machine learning addresses this significant challenge through what is termed concept drift. Concept drift occurs any time a data distribution changes over time. This dissertation draws from two key characteristics of concept drift in machine learning known to impact the performance of learning models, and in-so-doing provides the first systematic exploration of concept drift (i.e., categorical change) in human perceptual category learning. Four experiments, each including one key change parameter (category base-rates, payoffs, or category structure [RB/II]), investigated the effect of rate of change (abrupt, gradual) and awareness of change (foretold or not) on decision criterion adaptation. Critically, Experiments 3 and 4 evaluated differences in categorical adaptation within explicit and implicit category learning tasks to determine if rate and awareness of change moderated any learning system differences. The results of these experiments inform current category learning theory and provide information for machine learning models of decision support in non-stationary environments.
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Date Issued
2018
Identifier
CFE0007114, ucf:51947
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0007114
How Much is Enough? Trauma Recall and the Exposure Therapy Process
Title
How Much is Enough? Trauma Recall and the Exposure Therapy Process.
Creator
Morrison, Krystal, Beidel, Deborah, Bowers, Clint, Bohil, Corey, University of Central Florida
Abstract / Description
Prevailing theoretical models of posttraumatic stress disorder (PTSD) as well as exposure therapy (EXP) methodology suggest that recall of a trauma is crucial to altering the conditioned fear response associated with PTSD (Benito (&) Walther, 2015; Craske et al., 2008; Foa (&) Kozak, 1986). However, it is unclear whether limited recall of the event impacts the EXP process and treatment outcomes. This study examined whether incomplete trauma recall affected pre-treatment PTSD severity, Initial...
Show morePrevailing theoretical models of posttraumatic stress disorder (PTSD) as well as exposure therapy (EXP) methodology suggest that recall of a trauma is crucial to altering the conditioned fear response associated with PTSD (Benito (&) Walther, 2015; Craske et al., 2008; Foa (&) Kozak, 1986). However, it is unclear whether limited recall of the event impacts the EXP process and treatment outcomes. This study examined whether incomplete trauma recall affected pre-treatment PTSD severity, Initial Fear Activation (IFA), Overall Fear Activation (OFA), Within-Session Habituation (WSH), Between-Session Habituation (BSH; overall extinction), average length of EXP sessions, number of EXP sessions, and post-treatment PTSD severity, in 166 veterans of Operation Enduring Freedom, Operation Iraqi Freedom, and Operation New Dawn, who completed EXP treatment. Contrary to predicted outcomes, the extent of recall did not attenuate veterans' participation in EXP as measured by IFA, OFA, WSH and BSH. Furthermore, less recall did not result in more severe pre-treatment PTSD, longer EXP sessions, more EXP sessions, or attenuated treatment response, as measured by the Clinician-Administered PTSD Scale for DSM-IV (CAPS; Weathers, Ruscio, (&) Keane, 1999) and PTSD Checklist Military Version (PCL-M; Weathers, Huska, (&) Keane, 1991) at pre- and post-treatment. This suggests that veterans who are unable to recall aspects of their traumatic experience can engage successfully and benefit equally from EXP akin to veterans who experience less difficulty recalling trauma details. This research is the first to examine trauma recall in the context of the EXP process and contributes to the current body of literature that aims to address the question: For whom do treatments work?
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Date Issued
2018
Identifier
CFE0007347, ucf:52116
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0007347
Neurological Reactivity to Personalized Odors and Sounds in Combat-related Posttraumatic Stress Disorder
Title
Neurological Reactivity to Personalized Odors and Sounds in Combat-related Posttraumatic Stress Disorder.
Creator
Gramlich, Michael, Neer, Sandra, Beidel, Deborah, Bohil, Corey, Batien, Bryan, University of Central Florida
Abstract / Description
Functional near-infrared spectroscopy (fNIRS) is a neurophysiological procedure that offers immense clinical utility due to its cost effectiveness, ease of use, and mobile application. Using fNIRS to measure neurological reactions to personalized trauma-related cues might strengthen diagnostic screening, tailor treatment planning, and improve detection of remission among individuals with posttraumatic stress disorder (PTSD). Odors elicit strong emotional responses but remain underutilized in...
Show moreFunctional near-infrared spectroscopy (fNIRS) is a neurophysiological procedure that offers immense clinical utility due to its cost effectiveness, ease of use, and mobile application. Using fNIRS to measure neurological reactions to personalized trauma-related cues might strengthen diagnostic screening, tailor treatment planning, and improve detection of remission among individuals with posttraumatic stress disorder (PTSD). Odors elicit strong emotional responses but remain underutilized in clinical research. This fNIRS study examined whether personalizing combat-related odors and sounds to have a higher or lower match to distressing combat experiences increased the observed neurological effect among combat veterans with and without combat-related PTSD. This study gathered data from 58 male, right-handed combat veterans of Iraq or Afghanistan, ages 26 to 68, recruited from the community. The results indicated a significant increase in activation at the left ventral lateral prefrontal cortex (VLPFC) following an interaction between higher PTSD severity and higher match ratings for the combat-related odors (R2 = .20, p = .003; f2 = .25). Furthermore, the left VLPFC showed a significant increase in activation following an interaction between having a PTSD diagnosis and higher match ratings for the combat-related odors (R2 = .25, p = .005; f2 = .33). The findings for the combat-related sounds were less clear. The left VLPFC is associated with facilitating regulation of memory and emotional processes. Overall, the presentation of odors with higher similarity to distressing combat experiences altered the neurological response of the prefrontal cortex and may contribute to better understanding of the neurophysiological mechanisms of combat-related PTSD.
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Date Issued
2019
Identifier
CFE0007809, ucf:52357
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0007809
Subjective measures of implicit categorization learning
Title
Subjective measures of implicit categorization learning.
Creator
Hill, Audrey, Bohil, Corey, Neider, Mark, Szalma, James, Rapport, Mark, University of Central Florida
Abstract / Description
The neuropsychological theory known as COVIS (COmpetition between Verbal and Implicit Systems) postulates that distinct brain systems compete during category learning. The explicit system involves conscious hypothesis testing about verbalizable rules, while the implicit system relies on procedural learning of rules that are difficult to verbalize. Specifically from a behavioral approach, COVIS has been supported through demonstrating empirical dissociations between explicit and implicit...
Show moreThe neuropsychological theory known as COVIS (COmpetition between Verbal and Implicit Systems) postulates that distinct brain systems compete during category learning. The explicit system involves conscious hypothesis testing about verbalizable rules, while the implicit system relies on procedural learning of rules that are difficult to verbalize. Specifically from a behavioral approach, COVIS has been supported through demonstrating empirical dissociations between explicit and implicit learning tasks. The current studies were designed to gain deeper understanding of implicit category learning through the implementation of a subjective measure of awareness, Meta d', which until now has not been validated within a COVIS framework. Meta d' is a measure of metacognitive accuracy. This is the ability to assess the accuracy of one's own performance. These three experiments evaluated the use of Meta d' as a valid predictor of task performance within a two-structure perceptual categorization task. Experiment 1 focuses on using Meta d' to parse out dissociations between awareness and performance through the phenomenon of Blind Sight and Blind Insight. Experiment 2 and 3 utilize a motor response mapping disruption to observe predicted decrements to the implicit learning system. Experiment 3 utilizes functional Near Infrared Spectroscopy (fNIRS) to measure hemodynamic changes in the Prefrontal Cortex as a function of category structure. Across the 3 experiments, Meta d' in conjunction with decision bound model fits were used to make accurate predictions about the differences in performance throughout implicit and explicit categorization tasks. These collective results indicate that metacognitive accuracy, an implicit structure, was highly sensitive to a whether a person is using the correct rule strategies through the task.
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Date Issued
2018
Identifier
CFE0007753, ucf:52376
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0007753
Gamification of Visual Search in Real World Scenes
Title
Gamification of Visual Search in Real World Scenes.
Creator
Hess, Alyssa, Neider, Mark, Szalma, James, Bohil, Corey, Paulson, Daniel, University of Central Florida
Abstract / Description
Gamification, or the application of game-like features in non-game contexts, has been growing in popularity over the last five years. Specifically, the successful gamification of applications (such as Waze, Foursquare, and Fitocracy) has begun a spike in gamification of more complex tasks, such as learning to use AutoCAD or Photoshop. However, much is unknown about the psychological mapping of gamification or how it translates to behavioral outcomes. This dissertation aims to compare three...
Show moreGamification, or the application of game-like features in non-game contexts, has been growing in popularity over the last five years. Specifically, the successful gamification of applications (such as Waze, Foursquare, and Fitocracy) has begun a spike in gamification of more complex tasks, such as learning to use AutoCAD or Photoshop. However, much is unknown about the psychological mapping of gamification or how it translates to behavioral outcomes. This dissertation aims to compare three distinct styles of gamification (avatars, points and feedback, and leaderboards) onto the three basic psychological needs (autonomy, competence, and relatedness). It will assess behavioral outcomes on a visual search task when gamification styles are used separately, compared against all three styles used in concert. The task chosen is a camouflage visual search task. This task was selected because it is both boring (as indicated by the Flow Short Scale) and difficult (as indicated by previous work). These features make it the ideal task to gamify. Results indicated that only in the full gamification condition was response time significantly faster than in the control condition, or no gamification. However, ANOVA evaluating differences in enjoyment, motivation, and stress indicated differences among the groups, suggesting that gamification may elicit psychological outcomes that may not necessarily manifest into behavioral outcomes. ANCOVA were used to evaluate group differences using relevant survey measures as covariates. These tests indicated differences among groups in all behavioral measures, though these differences were most pronounced in response time measures. Future directions involving gamification based on personality type, as well as suggestions on best practice for gamification in the future are discussed.
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Date Issued
2017
Identifier
CFE0006601, ucf:51264
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0006601
Rumination and executive dysfunction: Risk factors for vascular depression
Title
Rumination and executive dysfunction: Risk factors for vascular depression.
Creator
Brush, David, Paulson, Daniel, Rapport, Mark, Bohil, Corey, University of Central Florida
Abstract / Description
Introduction: The widely-supported vascular depression hypothesis is underspecified with respect to cognitive mechanisms by which high cerebrovascular burden (CVB) and neuropathology relate to depressive symptoms. Integration of the vascular depression hypothesis with the CaR-FA-X model, a framework of affect regulation mechanisms, suggest that Rumination (R) and executive dysfunction (X) may increase due to altered recruitment of the dorsolateral prefrontal cortex resulting from high CVB and...
Show moreIntroduction: The widely-supported vascular depression hypothesis is underspecified with respect to cognitive mechanisms by which high cerebrovascular burden (CVB) and neuropathology relate to depressive symptoms. Integration of the vascular depression hypothesis with the CaR-FA-X model, a framework of affect regulation mechanisms, suggest that Rumination (R) and executive dysfunction (X) may increase due to altered recruitment of the dorsolateral prefrontal cortex resulting from high CVB and underlying neuropathology. This process would contribute to depressive symptomatology among older adults with high CVB. The progression of examined hypotheses included mediation models examining mechanistic relationships between predictors (CVB, DLPFC activation), cognitive correlates (rumination, executive functioning), and affective outcomes (depressive symptoms). Method: A sample of 52 community-dwelling, stroke-free, individuals over the age of 70, without history of severe mental illness, dementia, or severe cognitive impairment, completed the Ruminative Responses Scale, provided self-reported cerebrovascular burden data (cardiac disease, hypertension, diabetes, high cholesterol), and completed executive function tasks (Stroop, Flanker) while their hemodynamic response was measured using fNIRS. The Geriatric Depression Scale was used to assess depressive symptomatology. Prefrontal cortical recruitment was assessed using functional near-infrared spectroscopy (fNIRS).Results: A progression of conventional and bootstrapped regression-based models broadly supported relationships between CVB and depressive symptoms, but not between DLPFC activation and depressive symptoms. No mechanistic relationships were found, with respect to analyses testing prospective cognitive mediators.Conclusions: Primary findings from this study indicate that cerebrovascular burden predicts depressive symptomatology among older adults and is related to a reduction in inhibitory control ability. Further, these findings inform CVB measurement and mental health implications of contrasting approaches to CVB measurement. A primary contribution of this thesis is that results appear to support utilization of fNIRS, a low-cost and accessible neuroimaging paradigm, for the study of lateralized cognition among older adults.
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Date Issued
2018
Identifier
CFE0006981, ucf:51648
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0006981
An Exploration of the Feasibility of Functional Near-Infrared Spectroscopy as a Neurofeedback Cueing System for the Mitigation of the Vigilance Decrement
Title
An Exploration of the Feasibility of Functional Near-Infrared Spectroscopy as a Neurofeedback Cueing System for the Mitigation of the Vigilance Decrement.
Creator
Hancock, Gabriella, Szalma, James, Mouloua, Mustapha, Bohil, Corey, Hoffman, Robert, Matthews, Gerald, University of Central Florida
Abstract / Description
Vigilance is the capacity for observers to maintain attention over extended periods of time, and has most often been operationalized as the ability to detect rare and critical signals (Davies (&) Parasuraman, 1982; Parasuraman, 1979; Warm, 1984). Humans, however, have natural physical and cognitive limitations that preclude successful long-term vigilance performance and consequently, without some means of assistance, failures in operator vigilance are likely to occur. Such a decline in...
Show moreVigilance is the capacity for observers to maintain attention over extended periods of time, and has most often been operationalized as the ability to detect rare and critical signals (Davies (&) Parasuraman, 1982; Parasuraman, 1979; Warm, 1984). Humans, however, have natural physical and cognitive limitations that preclude successful long-term vigilance performance and consequently, without some means of assistance, failures in operator vigilance are likely to occur. Such a decline in monitoring performance over time has been a robust finding in vigilance experiments for decades and has been called the vigilance decrement function (Davies (&) Parasuraman, 1982; Mackworth, 1948). One of the most effective countermeasures employed to maintain effective performance has been cueing: providing the operator with a reliable prompt concerning signal onset probability. Most protocols have based such cues on task-related or environmental factors. The present dissertation examines the efficacy of cueing when nominally based on operator state (i.e., blood oxygenation of cortical tissue) in a novel vigilance task incorporating dynamic displays over three studies. Results pertaining to performance outcomes, physiological measures (cortical blood oxygenation and heart rate variability), and perceived workload and stress are interpreted via Signal Detection Theory and the Resource Theory of vigilance.
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Date Issued
2017
Identifier
CFE0006599, ucf:51286
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0006599
Integration of Multidimensional Signal Detection Theory with Fuzzy Signal Detection Theory
Title
Integration of Multidimensional Signal Detection Theory with Fuzzy Signal Detection Theory.
Creator
O'Connell, Maureen, Szalma, James, Hancock, Peter, Bohil, Corey, Reinerman, Lauren, University of Central Florida
Abstract / Description
Signal detection theory (SDT) has proven to be a robust and useful statistical model for analyzing human performance in detection and decision making tasks. As with many models extensions have been proposed in order capture and represent the real world to a greater degree. Multidimensional Signal Detection Theory (MSDT) has had success in describing and modeling complex signals, signals that are comprised by more than one identifiable component dimension. Fuzzy Signal Detection Theory (FSDT)...
Show moreSignal detection theory (SDT) has proven to be a robust and useful statistical model for analyzing human performance in detection and decision making tasks. As with many models extensions have been proposed in order capture and represent the real world to a greater degree. Multidimensional Signal Detection Theory (MSDT) has had success in describing and modeling complex signals, signals that are comprised by more than one identifiable component dimension. Fuzzy Signal Detection Theory (FSDT) has had success in modeling and measuring human performance in cases where there exist ambiguity in the signal or response dimension characteristics, through the application of fuzzy set theory to the definition of the performance outcome categories. Multidimensional Fuzzy Signal Detection Theory (MFSDT) was developed to accommodate simultaneously both the multidimensionality of a signal and the fuzzification of outcome categories in order to integrate the two extensions. A series of three studies were performed to develop and test the theory. One study's purpose was to develop and derive multidimensional mapping functions, the aspect of MFSDT where MSDT and FSDT were integrated. Two receiver operating characteristic (ROC) studies were performed, one simulated and one empirical. The results from both ROC analysis indicated that for perceptually separable and perceptually integral complex stimuli that MFDST is a viable methodological approach to analyzing performance of signal detection tasks where there are complex signals with ambiguous signal characteristics.
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Date Issued
2015
Identifier
CFE0005983, ucf:50763
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0005983
A Multimedia Approach to Game-Based Training: Exploring the Effects of the Modality and Temporal Contiguity Principles on Learning in a Virtual Environment
Title
A Multimedia Approach to Game-Based Training: Exploring the Effects of the Modality and Temporal Contiguity Principles on Learning in a Virtual Environment.
Creator
Serge, Stephen, Mouloua, Mustapha, Bohil, Corey, Bowers, Clint, Priest Walker, Heather, University of Central Florida
Abstract / Description
There is an increasing interest in using video games as a means to deliver training to individuals learning new skills or tasks. However, current research lacks a clear method of developing effective instructional material when these games are used as training tools and explaining how gameplay may affect learning. The literature contains multiple approaches to training and GBT but generally lacks a foundational-level and theoretically relevant approach to how people learn specifically from...
Show moreThere is an increasing interest in using video games as a means to deliver training to individuals learning new skills or tasks. However, current research lacks a clear method of developing effective instructional material when these games are used as training tools and explaining how gameplay may affect learning. The literature contains multiple approaches to training and GBT but generally lacks a foundational-level and theoretically relevant approach to how people learn specifically from video games and how to design instructional guidance within these gaming environments. This study investigated instructional delivery within GBT. Video games are a form of multimedia, consisting of both imagery and sounds. The Cognitive Theory of Multimedia Learning (CTML; Mayer 2005) explicitly describes how people learn from multimedia information, consisting of a combination of narration (words) and animation (pictures). This study empirically examined the effects of the modality and temporal contiguity principles on learning in a game-based virtual environment. Based on these principles, it was hypothesized that receiving either voice or embedded training would result in better performance on learning measures. Additionally, receiving a combination of voice and embedded training would lead to better performance on learning measures than all other instructional conditions.A total of 128 participants received training on the role and procedures related to the combat lifesaver (-) a non-medical soldier who receives additional training on combat-relevant lifesaving medical procedures. Training sessions involved an instructional presentation manipulated along the modality (voice or text) and temporal contiguity (embedded in the game or presented before gameplay) principles. Instructional delivery was manipulated in a 2x2 between-subjects design with four instructional conditions: Upfront-Voice, Upfront-Text, Embedded-Voice, and Embedded-Text. Results indicated that: (1) upfront instruction led to significantly better retention performance than embedded instructional regardless of delivery modality; (2) receiving voice-based instruction led to better transfer performance than text-based instruction regardless of presentation timing; (3) no differences in performance were observed on the simple application test between any instructional conditions; and (4) a significant interaction of modality-by-temporal contiguity was obtained. Simple effects analysis indicated differing effects along modality within the embedded instruction group, with voice recipients performing better than text (p = .012). Individual group comparisons revealed that the upfront-voice group performed better on retention than both embedded groups (p = .006), the embedded-voice group performed better on transfer than the upfront text group (p = .002), and the embedded-voice group performed better on the complex application test than the embedded-text group (p =.012). Findings indicated partial support for the application of the modality and temporal contiguity principles of CTML in interactive GBT. Combining gameplay (i.e., practice) with instructional presentation both helps and hinders working memory's ability to process information. Findings also explain how expanding CTML into game-based training may fundamentally change how a person processes information as a function of the specific type of knowledge being taught. Results will drive future systematic research to test and determine the most effective means of designing instruction for interactive GBT. Further theoretical and practical implications will be discussed.
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Date Issued
2014
Identifier
CFE0005548, ucf:50271
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0005548