Current Search: fNIRS (x)
-
-
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.
Show less
-
Date Issued
-
2015
-
Identifier
-
CFH0004765, ucf:45348
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFH0004765
-
-
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.
Show less
-
Date Issued
-
2015
-
Identifier
-
CFH0004870, ucf:45471
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFH0004870
-
-
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.
Show less
-
Date Issued
-
2014
-
Identifier
-
CFH0004591, ucf:45231
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFH0004591
-
-
Title
-
Simultaneous Use of Physiological Sensors for a Neuromarketing Task.
-
Creator
-
Descheneaux, Charles, Reinerman, Lauren, Barber, Daniel, Karwowski, Waldemar, Goldiez, Brian, University of Central Florida
-
Abstract / Description
-
ABSTRACTPhysiological measurements have become more popular in Psychological research over the past ten years. These advancements allowed different objective sensors to become another measurement tool in a scientific arsenal of collecting data. Traditionally, performance and after task subjective measures have been used for most studies in Psychological research. With the opportunity to use these subjective measures along with objective measures, more data can be collected during research and...
Show moreABSTRACTPhysiological measurements have become more popular in Psychological research over the past ten years. These advancements allowed different objective sensors to become another measurement tool in a scientific arsenal of collecting data. Traditionally, performance and after task subjective measures have been used for most studies in Psychological research. With the opportunity to use these subjective measures along with objective measures, more data can be collected during research and therefore potentially produce better quality conclusions.Eye Tracking (ET), functional near infrared (fNIR), transcranial Doppler ultrasound (TCD), electrocardiogram (EKG) and the electroencephalogram (EEG) have shown great promise in their ability to produce reliable and powerful objective data for research. Consequently, these devices are being used at the same time. The simultaneous use has the potential for interference between devices. Further, these devices are used on human subjects who can find these devices uncomfortable. These issues have the ability to skew data simply due to the measurement devices used.The effort of this study was to determine if the above devices could be used simultaneously without affecting their data quality, determine if difference combinations are more or less beneficial and determine if the combination of sensors have an effect on participant experience. A negative effect from discomfort has the potential to effect data. A study was conducted utilizing the ET, EEG, EKG, fNIR and TCD together in various combinations and also alone to determine if data is compromised and to determine if the combinations have an effect on participant experience.
Show less
-
Date Issued
-
2018
-
Identifier
-
CFE0007323, ucf:52130
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0007323
-
-
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.
Show less
-
Date Issued
-
2019
-
Identifier
-
CFE0007809, ucf:52357
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0007809
-
-
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.
Show less
-
Date Issued
-
2018
-
Identifier
-
CFE0007753, ucf:52376
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0007753
-
-
Title
-
Posttraumatic Stress Disorder or Combat Experience? A Functional Near-infrared Spectroscopy Study of Trauma-related Auditory and Olfactory Cues.
-
Creator
-
Gramlich, Michael, Neer, Sandra, Bowers, Clint, Beidel, Deborah, University of Central Florida
-
Abstract / Description
-
While the clinical communities are aware of the prevalence of posttraumatic stress disorder (PTSD) among OEF/OIF/OND veterans, further efforts are necessary to bolster comprehensive strategies for assessment and treatment. The purpose of this study was to investigate whether a combat-related PTSD symptom provocation paradigm would elicit unique neurological responses via functional near-infrared spectroscopy across three groups (-) combat veterans with PTSD, combat veterans without PTSD, and...
Show moreWhile the clinical communities are aware of the prevalence of posttraumatic stress disorder (PTSD) among OEF/OIF/OND veterans, further efforts are necessary to bolster comprehensive strategies for assessment and treatment. The purpose of this study was to investigate whether a combat-related PTSD symptom provocation paradigm would elicit unique neurological responses via functional near-infrared spectroscopy across three groups (-) combat veterans with PTSD, combat veterans without PTSD, and nonmilitary participants without PTSD. Results indicated that combat veterans with PTSD demonstrated significant activation during exposure to a trauma-related sound compared to nonmilitary personnel at channels 14 (d = 1.03) and 15 (d = 1.30) and combat veterans without PTSD at channel 14 (d = 0.87). Specifically, this increased neural activation was approximately located in the right superior/medial prefrontal cortex (BA 9/10), associated with evaluating cue-familiarity and emotional detachment. Results were less clear with respect to a combat-related odor. These results suggest a specific neurophysiological response to trauma-related cues and if replicated, may offer a biomarker for combat-related PTSD. Such a response could provide incremental validity over diagnostic assessments alone and assist in planning and monitoring of treatment outcome.
Show less
-
Date Issued
-
2017
-
Identifier
-
CFE0006596, ucf:51297
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0006596
-
-
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.
Show less
-
Date Issued
-
2016
-
Identifier
-
CFH2000086, ucf:45502
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFH2000086
-
-
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.
Show less
-
Date Issued
-
2013
-
Identifier
-
CFH0004478, ucf:45070
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFH0004478
-
-
Title
-
An investigation of physiological measures in a marketing decision task.
-
Creator
-
Lerma, Nelson, Karwowski, Waldemar, Elshennawy, Ahmad, Xanthopoulos, Petros, Reinerman, Lauren, University of Central Florida
-
Abstract / Description
-
The objective of the present study was to understand the use of physiological measures as an alternative to traditional market research tools, such as self-reporting measures and focus groups. For centuries, corporations and researchers have relied almost exclusively on traditional measures to gain insights into consumer behavior. Oftentimes, traditional methods have failed to accurately predict consumer demand, and this has prompted corporations to explore alternative methods that will...
Show moreThe objective of the present study was to understand the use of physiological measures as an alternative to traditional market research tools, such as self-reporting measures and focus groups. For centuries, corporations and researchers have relied almost exclusively on traditional measures to gain insights into consumer behavior. Oftentimes, traditional methods have failed to accurately predict consumer demand, and this has prompted corporations to explore alternative methods that will accurately forecast future sales. One the most promising alternative methods currently being investigated is the use of physiological measures as an indication of consumer preference. This field, also referred to as neuromarketing, has blended the principles of psychology, neuroscience, and market research to explore consumer behavior from a physiological perspective. The goal of neuromarketing is to capture consumer behavior through the use of physiological sensors. This study investigated the extent to which physiological measures where correlated to consumer preferences by utilizing five physiological sensors which included two neurological sensors (EEG and ECG) two hemodynamic sensors (TCD and fNIR) and one optic sensor (eye-tracking). All five physiological sensors were used simultaneously to capture and record physiological changes during four distinct marketing tasks. The results showed that only one physiological sensor, EEG, was indicative of concept type and intent to purchase. The remaining four physiological sensors did not show any significant differences for concept type or intent to purchase.Furthermore, Machine Learning Algorithms (MLAs) were used to determine the extent to which MLAs (Na(&)#239;ve Bayes, Multilayer Perceptron, K-Nearest Neighbor, and Logistic Regression) could classify physiological responses to self-reporting measures obtained during a marketing task. The results demonstrated that Multilayer Perceptron, on average, performed better than the other MLAs for intent to purchase and concept type. It was also evident that the models faired best with the most popular concept when categorizing the data based on intent to purchase or final selection. Overall, the four models performed well at categorizing the most popular concept and gave some indication to the extent to which physiological measures are capable of capturing intent to purchase. The research study was intended to help better understand the possibilities and limitations of physiological measures in the field of market research. Based on the results obtained, this study demonstrated that certain physiological sensors are capable of capturing emotional changes, but only when the emotional response between two concepts is significantly different. Overall, physiological measures hold great promise in the study of consumer behavior, providing great insight on the relationship between emotions and intentions in market research.
Show less
-
Date Issued
-
2015
-
Identifier
-
CFE0006345, ucf:51563
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0006345
-
-
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.
Show less
-
Date Issued
-
2018
-
Identifier
-
CFE0006981, ucf:51648
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0006981
-
-
Title
-
Investigating the universality and comprehensive ability of measures to assess the state of workload.
-
Creator
-
Abich, Julian, Reinerman, Lauren, Lackey, Stephanie, Szalma, James, Taylor, Grant, University of Central Florida
-
Abstract / Description
-
Measures of workload have been developed on the basis of the various definitions, some are designed to capture the multi-dimensional aspects of a unitary resource pool (Kahneman, 1973) while others are developed on the basis of multiple resource theory (Wickens, 2002). Although many theory based workload measures exist, others have often been constructed to serve the purpose of specific experimental tasks. As a result, it is likely that not every workload measure is reliable and valid for all...
Show moreMeasures of workload have been developed on the basis of the various definitions, some are designed to capture the multi-dimensional aspects of a unitary resource pool (Kahneman, 1973) while others are developed on the basis of multiple resource theory (Wickens, 2002). Although many theory based workload measures exist, others have often been constructed to serve the purpose of specific experimental tasks. As a result, it is likely that not every workload measure is reliable and valid for all tasks, much less each domain. To date, no single measure, systematically tested across experimental tasks, domains, and other measures is considered a universal measure of workload. Most researchers would argue that multiple measures from various categories should be applied to a given task to comprehensively assess workload. The goal for Study 1 to establish task load manipulations for two theoretically different tasks that induce distinct levels of workload assessed by both subjective and performance measures was successful. The results of the subjective responses support standardization and validation of the tasks and demands of that task for investigating workload. After investigating the use of subjective and objective measures of workload to identify a universal and comprehensive measure or set of measures, based on Study 2, it can only be concluded that not one or a set of measures exists. Arguably, it is not to say that one will never be conceived and developed, but at this time, one does not reside in the psychometric catalog. Instead, it appears that a more suitable approach is to customize a set of workload measures based on the task. The novel approach of assessing the sensitivity and comprehensive ability of conjointly utilizing subjective, performance, and physiological workload measures for theoretically different tasks within the same domain contributes to the theory by laying the foundation for improving methodology for researching workload. The applicable contribution of this project is a stepping-stone towards developing complex profiles of workload for use in closed-loop systems, such as human-robot team interaction. Identifying the best combination of workload measures enables human factors practitioners, trainers, and task designers to improve methodology and evaluation of system designs, training requirements, and personnel selection.
Show less
-
Date Issued
-
2013
-
Identifier
-
CFE0005119, ucf:50675
-
Format
-
Document (PDF)
-
PURL
-
http://purl.flvc.org/ucf/fd/CFE0005119