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- Title
- ADHD AND WORKING MEMORY: THE IMPACT OF CENTRAL EXECUTIVE DEFICITS AND OVERWHELMING STORAGE/REHEARSAL CAPACITY ON OBSERVED INATTENTIVE BEHAVIOR.
- Creator
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Kofler, Michael, Rapport, Mark, University of Central Florida
- Abstract / Description
-
Inattentive behavior is considered a core and pervasive feature of ADHD; however, an alternative model challenges this premise and hypothesizes a functional relationship between working memory and inattentive behavior. The current study investigated whether inattentive behavior in children with ADHD is functionally related to domain-general central executive and/or subsidiary storage/rehearsal components of working memory. Objective observations of children's attentive behavior by...
Show moreInattentive behavior is considered a core and pervasive feature of ADHD; however, an alternative model challenges this premise and hypothesizes a functional relationship between working memory and inattentive behavior. The current study investigated whether inattentive behavior in children with ADHD is functionally related to domain-general central executive and/or subsidiary storage/rehearsal components of working memory. Objective observations of children's attentive behavior by independent observers were conducted while children with ADHD (n=15) and typically developing children (n=14) completed 10 counterbalanced tasks that differentially manipulated central executive, phonological storage/rehearsal, and visuospatial storage/rehearsal demands. Results of latent variable and effect size confidence interval analyses revealed two conditions that completely accounted for the attentive behavior deficits in children with ADHD: (a) placing demands on central executive processing, the effect of which is evident under even low cognitive loads, and (b) overwhelming storage/rehearsal capacity, which has similar effects on children with ADHD and typically developing children but occurs at lower cognitive loads for children with ADHD. Collectively, the results challenge the current DSM-IV conceptualization of ADHD and indicate that inattentive behavior may be secondary to underlying working memory deficits.
Show less - Date Issued
- 2009
- Identifier
- CFE0002695, ucf:48201
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002695
- Title
- THE RELATIONSHIP BETWEEN SELF-REPORTED CHRONIC STRESS AND DIVIDED ATTENTION PERFORMANCE.
- Creator
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Petrac, Diane, Bedwell, Jeffrey, University of Central Florida
- Abstract / Description
-
While previous research has extensively examined the effect of acute stress on cognitive performance, relatively little research has explored the relationship between chronic stress and cognitive performance. The current study aimed to control for current state anxiety to better isolate more chronic stress, when examining the relationship with performance on divided attention tasks. Fifty-four university undergraduates, who self-reported a wide range of perceived chronic stress (10-item...
Show moreWhile previous research has extensively examined the effect of acute stress on cognitive performance, relatively little research has explored the relationship between chronic stress and cognitive performance. The current study aimed to control for current state anxiety to better isolate more chronic stress, when examining the relationship with performance on divided attention tasks. Fifty-four university undergraduates, who self-reported a wide range of perceived chronic stress (10-item Perceived Stress Scale), completed the Trail-Making Test and a dual (auditory and visual) Continuous Performance Test (CPT). Hierarchical regressions were performed to explore cognitive predictors of chronic perceived stress. After covarying for state anxiety (state portion of State-Trait Anxiety Inventory), the most statistically significant predictor (via stepwise entry) was the auditory omission error change score (dual minus single condition), which showed a medium effect size (r = .36). Results have practical safety implications, as the implementation of an efficient and inexpensive measure of self-reported stress may predict future job-related errors in high-stress professions that require divided attention.
Show less - Date Issued
- 2006
- Identifier
- CFE0001509, ucf:47125
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001509
- Title
- A Randomized Trial of Attention Training for Generalized Social Phobia: Does Attention Training Change Social Behavior?.
- Creator
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Bunnell, Brian, Beidel, Deborah, Cassisi, Jeffrey, Rapport, Mark, University of Central Florida
- Abstract / Description
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The use of attention training protocols for the treatment of generalized social anxiety disorder (SAD) is undergoing increased examination. Initial investigations were positive but more recent investigations have been less supportive of the treatment paradigm. One significant limitation of current investigations may be over-reliance on self-report. In this investigation, we expanded on initial investigations by using a multimodal assessment of patient functioning (i.e., including behavioral...
Show moreThe use of attention training protocols for the treatment of generalized social anxiety disorder (SAD) is undergoing increased examination. Initial investigations were positive but more recent investigations have been less supportive of the treatment paradigm. One significant limitation of current investigations may be over-reliance on self-report. In this investigation, we expanded on initial investigations by using a multimodal assessment of patient functioning (i.e., including behavioral assessment). Patients with a primary diagnosis of SAD (n = 31) were randomly assigned to eight sessions of attention training (n = 15) or placebo/control (n = 16). Participants were assessed at pre- and post-treatment via self- and clinician-report of social anxiety as well as anxious and behavioral response to two in vivo social interactions. Results revealed no differences between groups at post-treatment for all study outcome variables, suggesting a lack of effect for the attention training condition. The results are concordant with recent investigations finding a lack of support for the use of attention training as an efficacious treatment for patients with SAD.
Show less - Date Issued
- 2013
- Identifier
- CFE0004658, ucf:49879
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004658
- Title
- Task Focused Robotic Imitation Learning.
- Creator
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Abolghasemi, Pooya, Boloni, Ladislau, Sukthankar, Gita, Shah, Mubarak, Willenberg, Bradley, University of Central Florida
- Abstract / Description
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For many years, successful applications of robotics were the domain of controlled environments, such as industrial assembly lines. Such environments are custom designed for the convenience of the robot and separated from human operators. In recent years, advances in artificial intelligence, in particular, deep learning and computer vision, allowed researchers to successfully demonstrate robots that operate in unstructured environments and directly interact with humans. One of the major...
Show moreFor many years, successful applications of robotics were the domain of controlled environments, such as industrial assembly lines. Such environments are custom designed for the convenience of the robot and separated from human operators. In recent years, advances in artificial intelligence, in particular, deep learning and computer vision, allowed researchers to successfully demonstrate robots that operate in unstructured environments and directly interact with humans. One of the major applications of such robots is in assistive robotics. For instance, a wheelchair mounted robotic arm can help disabled users in the performance of activities of daily living (ADLs) such as feeding and personal grooming. Early systems relied entirely on the control of the human operator, something that is difficult to accomplish by a user with motor and/or cognitive disabilities. In this dissertation, we are describing research results that advance the field of assistive robotics. The overall goal is to improve the ability of the wheelchair / robotic arm assembly to help the user with the performance of the ADLs by requiring only high-level commands from the user. Let us consider an ADL involving the manipulation of an object in the user's home. This task can be naturally decomposed into two components: the movement of the wheelchair in such a way that the manipulator can conveniently grasp the object and the movement of the manipulator itself. This dissertation we provide an approach for addressing the challenge of finding the position appropriate for the required manipulation. We introduce the ease-of-reach score (ERS), a metric that quantifies the preferences for the positioning of the base while taking into consideration the shape and position of obstacles and clutter in the environment. As the brute force computation of ERS is computationally expensive, we propose a machine learning approach to estimate the ERS based on features and characteristics of the obstacles. This dissertation addresses the second component as well, the ability of the robotic arm to manipulate objects. Recent work in end-to-end learning of robotic manipulation had demonstrated that a deep learning-based controller of vision-enabled robotic arms can be thought to manipulate objects from a moderate number of demonstrations. However, the current state of the art systems are limited in robustness to physical and visual disturbances and do not generalize well to new objects. We describe new techniques based on task-focused attention that show significant improvement in the robustness of manipulation and performance in clutter.
Show less - Date Issued
- 2019
- Identifier
- CFE0007771, ucf:52392
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007771
- Title
- CROSS-MODAL DISTRACTION ON SIMULTANEOUS TRANSLATION: LANGUAGE INTERFERENCE IN SPANISH-ENGLISH BILINGUALS.
- Creator
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Young, Violet A, Modianos, Doan, University of Central Florida
- Abstract / Description
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Bilingualism has been studied extensively in multiple disciplines, yet we are still trying to figure out how exactly bilinguals think. A bilingual advantage has been observed in various experimental studies, but also has not been observed in many other studies. A bilingual advantage has been shown in tasks using selective attention. These tasks study the effects of language interference, where two types of interference are observed: interlingual (between-languages) and intralingual (within...
Show moreBilingualism has been studied extensively in multiple disciplines, yet we are still trying to figure out how exactly bilinguals think. A bilingual advantage has been observed in various experimental studies, but also has not been observed in many other studies. A bilingual advantage has been shown in tasks using selective attention. These tasks study the effects of language interference, where two types of interference are observed: interlingual (between-languages) and intralingual (within one language). This study examined language interference in Spanish-English bilinguals, using an auditory-visual simultaneous translation experimental setup. 16 college English monolinguals and 17 college Spanish-English bilinguals were tested. The task was to ignore the word in the headphones and to translate/repeat the word on the screen into English. Distractor words went to either the right, left, or both headphone ears. Subjects were given 72 words to translate, words were randomized, and ear of the distractor word was randomized. The monolingual group was not affected by any independent variables tested except screen word length. Bilinguals did worse when the word and audio were in Spanish, and when the word and audio were different words. No ear advantage was observed. Proficiency levels and first language had no effects on bilingual performance. More intralingual interference was observed for bilinguals only, no significant interference occurred for monolinguals. A slight bilingual advantage was found but not fully, because of the high load of the task and introduction of another language. In conclusion, bilinguals did not have a cognitive advantage in this experiment setup.
Show less - Date Issued
- 2018
- Identifier
- CFH2000448, ucf:45844
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000448
- Title
- ORIENTING OF VISUAL-SPATIAL ATTENTION WITH AUGMENTED REALITY: EFFECTS OF SPATIAL AND NON-SPATIAL MULTI-MODAL CUES.
- Creator
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Jerome, Christian, Mouloua, Mustapha, University of Central Florida
- Abstract / Description
-
Advances in simulation technology have brought about many improvements to the way we train tasks, as well as how we perform tasks in the operational field. Augmented reality (AR) is an example of how to enhance the user's experience in the real world with computer generated information and graphics. Visual search tasks are known to be capacity demanding and therefore may be improved by training in an AR environment. During the experimental task, participants searched for enemies (while...
Show moreAdvances in simulation technology have brought about many improvements to the way we train tasks, as well as how we perform tasks in the operational field. Augmented reality (AR) is an example of how to enhance the user's experience in the real world with computer generated information and graphics. Visual search tasks are known to be capacity demanding and therefore may be improved by training in an AR environment. During the experimental task, participants searched for enemies (while cued from visual, auditory, tactile, combinations of two, or all three modality cues) and tried to shoot them while avoiding shooting the civilians (fratricide) for two 2-minute low-workload scenarios, and two 2-minute high-workload scenarios. The results showed significant benefits of attentional cuing on visual search task performance as revealed by benefits in reaction time and accuracy from the presence of the haptic cues and auditory cues when displayed alone and the combination of the visual and haptic cues together. Fratricide occurrence was shown to be amplified by the presence of the audio cues. The two levels of workload produced differences within individual's task performance for accuracy and reaction time. Accuracy and reaction time were significantly better with the medium cues than all the others and the control condition during low workload and marginally better during high workload. Cue specificity resulted in a non-linear function in terms of performance in the low workload condition. These results are in support of Posner's (1978) theory that, in general, cueing can benefit locating targets in the environment by aligning the attentional system with the visual input pathways. The cue modality does not have to match the target modality. This research is relevant to potential applications of AR technology. Furthermore, the results identify and describe perceptual and/or cognitive issues with the use of displaying computer generated augmented objects and information overlaid upon the real world. The results also serve as a basis for providing a variety of training and design recommendations to direct attention during military operations. Such recommendations include cueing the Soldier to the location of hazards, and mitigating the effects of stress and workload.
Show less - Date Issued
- 2006
- Identifier
- CFE0001481, ucf:47092
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001481
- Title
- CLASSROOM OBSERVATIONS OF ATTENTION-DEFICIT/HYPERACTIVITY DISORDER: PATTERNS AND CHARACTERISTICS OF ATTENTION OVER TIME.
- Creator
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Timko Jr, Thomas, Rapport, Mark, University of Central Florida
- Abstract / Description
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Investigated differences in attentional processes between children diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD) and their classroom peers. Models of attention gleaned from laboratory experiments provided a theoretical structure for hypothesizing between-group attentional differences. Seventy-five children with ADHD and 36 normal control children were observed in their regular classrooms over a 1-week time interval. Explication of between-group differences revealed that...
Show moreInvestigated differences in attentional processes between children diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD) and their classroom peers. Models of attention gleaned from laboratory experiments provided a theoretical structure for hypothesizing between-group attentional differences. Seventy-five children with ADHD and 36 normal control children were observed in their regular classrooms over a 1-week time interval. Explication of between-group differences revealed that children with ADHD were approximately 21% less attentive on average. Both groups exhibited an accelerating-decelerating pattern of attention over time, however, children with ADHD cycled at a rate twice that of same-aged peers. Six variables derived from observed attention were examined for diagnostic utility using logistical regression, odds ratios, total predictive value, and receiver operating characteristics. Implications of these findings are discussed.
Show less - Date Issued
- 2005
- Identifier
- CFE0000686, ucf:46485
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000686
- Title
- CLASSROOM OBSERVATION OF CHILDREN WITH ADHD AND THEIR PEERS: A META-ANALYTIC REVIEW.
- Creator
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Kofler, Michael, Rapport, Mark, University of Central Florida
- Abstract / Description
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Meta-analysis of 23 between-group direct observation studies of children with ADHD and typically developing peers indicates significant deficiencies in children with ADHD's ability to pay attention in classroom settings. Comparison with 59 single case design studies of children with ADHD suggests generalizability of between-group comparisons. Weighted regression analysis determined that several methodological differences – sample characteristics, diagnostic procedures, and observational...
Show moreMeta-analysis of 23 between-group direct observation studies of children with ADHD and typically developing peers indicates significant deficiencies in children with ADHD's ability to pay attention in classroom settings. Comparison with 59 single case design studies of children with ADHD suggests generalizability of between-group comparisons. Weighted regression analysis determined that several methodological differences – sample characteristics, diagnostic procedures, and observational coding schema – have significant effects on observed levels of attentive behavior in the classroom. Best case estimation indicates that after accounting for these factors, children with ADHD are on-task approximately 65% of the time compared to 85% for their classroom peers. Children with ADHD were also more variable in their attentive behavior across studies. Implications for conceptual models of ADHD are discussed.
Show less - Date Issued
- 2006
- Identifier
- CFE0000942, ucf:46752
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000942
- Title
- Examining Energetic and Structural Components of Knowledge of Result Using a Vigilance Paradigm.
- Creator
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Fraulini, Nicholas, Szalma, James, Mouloua, Mustapha, Hancock, Peter, Matthews, Gerald, University of Central Florida
- Abstract / Description
-
Vigilance, or the ability to maintain attention to stimuli over a prolonged period of time (Davies (&) Parasuraman, 1982; Warm (&) Jerison, 1984), has been a troublesome research topic since World War II. Scientists have sought to counteract performance declines in vigilance tasks by training observers on these tasks. Though an extensive literature has been developed to examine the effectiveness of these techniques, the mechanisms by which many forms of vigilance training help performance are...
Show moreVigilance, or the ability to maintain attention to stimuli over a prolonged period of time (Davies (&) Parasuraman, 1982; Warm (&) Jerison, 1984), has been a troublesome research topic since World War II. Scientists have sought to counteract performance declines in vigilance tasks by training observers on these tasks. Though an extensive literature has been developed to examine the effectiveness of these techniques, the mechanisms by which many forms of vigilance training help performance are largely unknown. The present dissertation seeks to further the understanding of how two forms of training for vigilance, practice and knowledge of result, function to improve observers' ability to remain vigilant as time on task increases. In addition to understanding these forms of training, this dissertation seeks to develop a training protocol that would train observers for vigilance without adversely affecting their cognitive resources. Finally, this dissertation utilizes this new training protocol to examine the potential for transfer of training, which has been a question for vigilance researchers for decades. Results relating to these three research questions are presented, as well as a discussion of how these results may inform or influence vigilance research in the future.
Show less - Date Issued
- 2017
- Identifier
- CFE0006876, ucf:51746
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006876
- Title
- Beyond Compliance: Examining the Role of Motivation in Vigilance Performance.
- Creator
-
Dewar, Alexis, Szalma, James, Sims, Valerie, Hancock, Peter, Matthews, Gerald, University of Central Florida
- Abstract / Description
-
Vigilance, or sustained attention, is the capacity to attend to information for a prolonged period of time (Davies (&) Parasuraman, 1982; Jerison, 1970; Warm, 1977). Due to limitations of the human nervous system, as well as the environmental context, attention can begin to wane over time. This results in a phenomenon referred to as the vigilance decrement, or a decline in vigilance performance as a function of time. The vigilance decrement can manifest as poorer attention and is thusly...
Show moreVigilance, or sustained attention, is the capacity to attend to information for a prolonged period of time (Davies (&) Parasuraman, 1982; Jerison, 1970; Warm, 1977). Due to limitations of the human nervous system, as well as the environmental context, attention can begin to wane over time. This results in a phenomenon referred to as the vigilance decrement, or a decline in vigilance performance as a function of time. The vigilance decrement can manifest as poorer attention and is thusly associated with poor performance, which is defined behaviorally as more lapses in the detection of critical signals and an increase in response time to these signals during watch. Given this, the present dissertation seeks to systematically examine the impact of two types of motivation (i.e., achievement motivation, autonomous motivation) on vigilance performance across four experiments. The present experiments manipulate information processing type, source complexity, and motivational task demands. Three hundred and ninety-eight participants completed either a cognitive task or sensory task, which were psychophysically equated in previous studies (Szalma (&) Teo, 2012; Teo, Szalma, (&) Schmidt, 2011), with or without motivational instructions, and with either low, medium, or high source complexity. Performance measures, perceived stress and workload, and changes to state motivation and engagement at pre-task and post-task are interpreted across three theories of information processing: resource-depletion theory, mind-wandering theory, and mindlessness theory. The results of each of the four studies are discussed in terms of overall support for the resource-depletionist account. The limitations of the present set of experiments and the future directions for research on motivation and sustained attention are also discussed.
Show less - Date Issued
- 2017
- Identifier
- CFE0006582, ucf:51312
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006582
- Title
- VIDEO CONTENT EXTRACTION: SCENE SEGMENTATION, LINKING AND ATTENTION DETECTION.
- Creator
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Zhai, Yun, Shah, Mubarak, University of Central Florida
- Abstract / Description
-
In this fast paced digital age, a vast amount of videos are produced every day, such as movies, TV programs, personal home videos, surveillance video, etc. This places a high demand for effective video data analysis and management techniques. In this dissertation, we have developed new techniques for segmentation, linking and understanding of video scenes. Firstly, we have developed a video scene segmentation framework that segments the video content into story units. Then, a linking method...
Show moreIn this fast paced digital age, a vast amount of videos are produced every day, such as movies, TV programs, personal home videos, surveillance video, etc. This places a high demand for effective video data analysis and management techniques. In this dissertation, we have developed new techniques for segmentation, linking and understanding of video scenes. Firstly, we have developed a video scene segmentation framework that segments the video content into story units. Then, a linking method is designed to find the semantic correlation between video scenes/stories. Finally, to better understand the video content, we have developed a spatiotemporal attention detection model for videos. Our general framework for temporal scene segmentation, which is applicable to several video domains, is formulated in a statistical fashion and uses the Markov chain Monte Carlo (MCMC) technique to determine the boundaries between video scenes. In this approach, a set of arbitrary scene boundaries are initialized at random locations and are further automatically updated using two types of updates: diffusion and jumps. The posterior probability of the target distribution of the number of scenes and their corresponding boundary locations are computed based on the model priors and the data likelihood. Model parameter updates are controlled by the MCMC hypothesis ratio test, and samples are collected to generate the final scene boundaries. The major contribution of the proposed framework is two-fold: (1) it is able to find weak boundaries as well as strong boundaries, i.e., it does not rely on the fixed threshold; (2) it can be applied to different video domains. We have tested the proposed method on two video domains: home videos and feature films. On both of these domains we have obtained very accurate results, achieving on the average of 86% precision and 92% recall for home video segmentation, and 83% precision and 83% recall for feature films. The video scene segmentation process divides videos into meaningful units. These segments (or stories) can be further organized into clusters based on their content similarities. In the second part of this dissertation, we have developed a novel concept tracking method, which links news stories that focus on the same topic across multiple sources. The semantic linkage between the news stories is reflected in the combination of both their visual content and speech content. Visually, each news story is represented by a set of key frames, which may or may not contain human faces. The facial key frames are linked based on the analysis of the extended facial regions, and the non-facial key frames are correlated using the global matching. The textual similarity of the stories is expressed in terms of the normalized textual similarity between the keywords in the speech content of the stories. The developed framework has also been applied to the task of story ranking, which computes the interestingness of the stories. The proposed semantic linking framework and the story ranking method have both been tested on a set of 60 hours of open-benchmark video data (CNN and ABC news) from the TRECVID 2003 evaluation forum organized by NIST. Above 90% system precision has been achieved for the story linking task. The combination of both visual and speech cues has boosted the un-normalized recall by 15%. We have developed PEGASUS, a content based video retrieval system with fast speech and visual feature indexing and search. The system is available on the web: http://pegasus.cs.ucf.edu:8080/index.jsp. Given a video sequence, one important task is to understand what is present or what is happening in its content. To achieve this goal, target objects or activities need to be detected, localized and recognized in either the spatial and/or temporal domain. In the last portion of this dissertation, we present a visual attention detection method, which automatically generates the spatiotemporal saliency maps of input video sequences. The saliency map is later used in the detections of interesting objects and activities in videos by significantly narrowing the search range. Our spatiotemporal visual attention model generates the saliency maps based on both the spatial and temporal signals in the video sequences. In the temporal attention model, motion contrast is computed based on the planar motions (homography) between images, which are estimated by applying RANSAC on point correspondences in the scene. To compensate for the non-uniformity of the spatial distribution of interest-points, spanning areas of motion segments are incorporated in the motion contrast computation. In the spatial attention model, we have developed a fast method for computing pixel-level saliency maps using color histograms of images. Finally, a dynamic fusion technique is applied to combine both the temporal and spatial saliency maps, where temporal attention is dominant over the spatial model when large motion contrast exists, and vice versa. The proposed spatiotemporal attention framework has been extensively applied on multiple video sequences to highlight interesting objects and motions present in the sequences. We have achieved 82% user satisfactory rate on the point-level attention detection and over 92% user satisfactory rate on the object-level attention detection.
Show less - Date Issued
- 2006
- Identifier
- CFE0001216, ucf:46944
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001216
- Title
- A COMPARISON OF ATTENTIONAL RESERVE CAPACITY ACROSS THREE SENSORY MODALITIES.
- Creator
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Brill, John, Gilson, Richard, University of Central Florida
- Abstract / Description
-
There are two theoretical approaches to the nature of attentional resources. One proposes a single, flexible pool of cognitive resources; the other poses there are multiple resources. This study was designed to systematically examine whether there is evidence for multiple resource theory using a counting task consisting of visual, auditory, and tactile signals using two experiments. The goal of the first experiment was the validation of a multi-modal secondary loading task. Thirty-two...
Show moreThere are two theoretical approaches to the nature of attentional resources. One proposes a single, flexible pool of cognitive resources; the other poses there are multiple resources. This study was designed to systematically examine whether there is evidence for multiple resource theory using a counting task consisting of visual, auditory, and tactile signals using two experiments. The goal of the first experiment was the validation of a multi-modal secondary loading task. Thirty-two participants performed nine variations of a multi-modal counting task incorporating three modalities and three demand levels. Performance and subjective ratings of workload were measured for each of the nine conditions of the within-subjects design. Significant differences were found on the basis of task demand level, irrespective of modality. Moreover, the perceived workload associated with the tasks differed by task demand level and not by modality. These results suggest the counting task is a valid means of imposing task demands across multiple modalities. The second experiment used the same counting task as a secondary load to a primary visual monitoring task, the system monitoring component of the Multi-Attribute Task Battery (MATB). The experimental conditions consisted of performing the system monitoring task alone as a reference and performing system monitoring combined with visual, auditory, or tactile counting. Thirty-one participants were exposed to all four experimental conditions in a within-subjects design. Performance on the primary and secondary tasks was measured, and subjective workload was assessed for each condition. Participants were instructed to maintain performance on the primary task, irrespective of condition, which they did so effectively. Secondary task performance for the visual-auditory and visual-tactile conditions was significantly better than for the visual-visual dual task condition. Subjective workload ratings were also consistent with the performance measures. These results clearly indicate that there is less interference for cross-modal tasks than for intramodal tasks. These results add evidence to multiple resource theory. Finally, these results have practical implications that include human performance assessment for display and alarm development, assessment of attentional reserve capacity for adaptive automation systems, and training.
Show less - Date Issued
- 2007
- Identifier
- CFE0001660, ucf:47234
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001660
- Title
- THE RELATIVE SENSITIVITY OF AN OLFACTORY IDENTIFICATION DEFICIT IN INDIVIDUALS WITH SCHIZOTYPAL PERSONALITY FEATURES.
- Creator
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Kamath, Vidyulata, Bedwell, Jeffrey, University of Central Florida
- Abstract / Description
-
Olfactory identification deficits have received recent attention as a potentially useful endophenotype for schizophrenia. Examination of this deficit in individuals with schizotypal personality features (SPF) offers an alternative approach to multiple confounds present when examining individuals with schizophrenia. The aim of the current study was to compare the relative sensitivity of performance on measures of olfaction identification and sustained attention to the presence of SPF. Twenty...
Show moreOlfactory identification deficits have received recent attention as a potentially useful endophenotype for schizophrenia. Examination of this deficit in individuals with schizotypal personality features (SPF) offers an alternative approach to multiple confounds present when examining individuals with schizophrenia. The aim of the current study was to compare the relative sensitivity of performance on measures of olfaction identification and sustained attention to the presence of SPF. Twenty-six undergraduates were defined as having SPF based on scoring in the top 10% of the Abbreviated Schizotypal Personality Questionnaire (SPQ-B; mean age 19.6, SD = 1.1; 62% female). These individuals were compared to twenty-six controls (scoring lower than half a standard deviation above the mean; mean age 19.8, SD = 1.6; 62% female). All participants were administered the Schizotypal Personality Disorder (SPD) section of the Structured Clinical Interview for DSM IV Axis II Personality Disorders (SCID-II). In addition, participants were administered the Brief Smell Identification Test (B-SIT) and a six-minute degraded-stimuli Continuous Performance Test (CPT). Group differences in performance indices of the CPT did not approach statistical significance. Similarly, there were no statistically significant group differences for males or females in performance on the B-SIT. Correlational analyses examined cognitive performance with a dimension score derived by summing quantitative ratings from the SPD items on the SCID-II. The SPD dimension score showed a statistically significant positive correlation with several performance indices of the CPT, including omission errors (rs(52) = .51, p < .001) and commission errors (rs(52) = .38, p < .005). In contrast, the B-SIT scores were not correlated with the SPD dimension score for males or females. Contrary to our hypothesis, results from the current study suggest that olfactory identification deficits may not represent a robust endophenotype consistently found in samples with schizotypal personality features. With regard to sustained attention, our differential findings suggest that schizotypal traits may be more adequately assessed through an interview by trained clinicians who use clinical judgment to determine the presence of phenotypic aspects of SPD (e.g., SCID-II), rather than relying on self-report measures (e.g., SPQ-B). Implications as well as limitations and future directions of these findings are discussed.
Show less - Date Issued
- 2007
- Identifier
- CFE0001675, ucf:47211
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001675
- Title
- INDIVIDUAL PREFERENCES IN THE USE OF AUTOMATION.
- Creator
-
Thropp, Jennifer, Hancock, Peter, University of Central Florida
- Abstract / Description
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As system automation increases and evolves, the intervention of the supervising operator becomes ever less frequent but ever more crucial. The adaptive automation approach is one in which control of tasks dynamically shifts between humans and machines, being an alternative to traditional static allocation in which task control is assigned during system design and subsequently remains unchanged during operations. It is proposed that adaptive allocation should adjust to the individual operators...
Show moreAs system automation increases and evolves, the intervention of the supervising operator becomes ever less frequent but ever more crucial. The adaptive automation approach is one in which control of tasks dynamically shifts between humans and machines, being an alternative to traditional static allocation in which task control is assigned during system design and subsequently remains unchanged during operations. It is proposed that adaptive allocation should adjust to the individual operators' characteristics in order to improve performance, avoid errors, and enhance safety. The roles of three individual difference variables relevant to adaptive automation are described: attentional control, desirability of control, and trait anxiety. It was hypothesized that these traits contribute to the level of performance for target detection tasks for different levels of difficulty as well as preferences for different levels of automation. The operators' level of attentional control was inversely proportional to automation level preferences, although few objective performance changes were observed. The effects of sensory modality were also assessed, and auditory signal detection was superior to visual signal detection. As a result, the following implications have been proposed: operators generally preferred either low or high automation while neglecting the intermediary level; preferences and needs for automation may not be congruent; and there may be a conservative response bias associated with high attentional control, notably in the auditory modality.
Show less - Date Issued
- 2006
- Identifier
- CFE0001096, ucf:46771
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001096
- Title
- MARITAL STATUS OF EXECUTIVES AND COMPANY PERFORMANCE.
- Creator
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Day, Ilona, Lu, Yan, University of Central Florida
- Abstract / Description
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This research paper explores differences in company performance levels, as measured by selected company fundamentals and annual return, with regard to the marital status of top executives, specifically the chief executive officer and the chief financial officer. It examines whether the differences in firm performance are determined by the marital status of the respective business executive. Groups of never married, married, and divorced executives are compared against each other to establish...
Show moreThis research paper explores differences in company performance levels, as measured by selected company fundamentals and annual return, with regard to the marital status of top executives, specifically the chief executive officer and the chief financial officer. It examines whether the differences in firm performance are determined by the marital status of the respective business executive. Groups of never married, married, and divorced executives are compared against each other to establish if and how the company performance changes between these groups. Summary statistics of the examined variables in conjunction with the results of the simple and multiple regression analyses indicate that marriage clearly has a detrimental effect on a firm's performance. By contrast, divorce is beneficial as it contributes to improved firm performance. As previous research has revealed, professional performance of top executives, particularly CEOs, as well as money managers is influenced by distractions originating in their personal life events. Because human attention is naturally limited, major life events, such as marriage or divorce, can have detrimental effects on the professional performance of a business executive, and therefore also on the firm performance. Consistent with the results of previous research, the data analysis identifies marital status of CEOs and CFOs as a significant determinant of firm performance.
Show less - Date Issued
- 2017
- Identifier
- CFH0000226, ucf:44671
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0000226
- Title
- ADHD BEHAVIOR PROBLEMS AND NEAR- AND LONG-TERM SCHOLASTIC ACHIEVEMENT: DIFFERENTIAL MEDIATING EFFECTS OF VERBAL AND VISUOSPATIAL MEMORY.
- Creator
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Sarver, Dustin, Rapport, Mark, University of Central Florida
- Abstract / Description
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The current study examined verbal and visuospatial memory abilities as potential mediators of the relationship among ADHD behavior problems and near- and long-term scholastic achievement. Scholastic achievement was measured initially and at 4-year follow-up in an ethnically diverse sample of children (N = 325). Nested composite (reading, math, language) and domain-specific reading structural equation models revealed that ADHD behavior problems exerted a negative influence on scholastic...
Show moreThe current study examined verbal and visuospatial memory abilities as potential mediators of the relationship among ADHD behavior problems and near- and long-term scholastic achievement. Scholastic achievement was measured initially and at 4-year follow-up in an ethnically diverse sample of children (N = 325). Nested composite (reading, math, language) and domain-specific reading structural equation models revealed that ADHD behavior problems exerted a negative influence on scholastic achievement measures, both initially and at follow-up. Much of this influence, however, was mediated by verbal memory's contribution to near-term achievement, whereas visuospatial memory contributed more robustly to long-term achievement. For the domain-specific math achievement model, the collective influence of verbal and visuospatial memory fully mediated the direct influence of ADHD behavior problems on near-term math achievement, and visuospatial memory alone contributed to both near- and long-term achievement. In all models, measured intelligence made no contribution to later achievement beyond its initial influence on early achievement. The results contribute to the understanding of the developmental trajectory of scholastic achievement, and have potential implications for developing remedial programs targeting verbal and visual memory deficits in children with ADHD behavior problems.
Show less - Date Issued
- 2010
- Identifier
- CFE0003502, ucf:48950
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003502
- Title
- An Investigation of the Effects of Neurofeedback Training on Attention Deficit-Hyperactivity Disorder (ADHD) Symptoms, Depression, Anxiety, and Academic Self-Efficacy in College Students.
- Creator
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Harris, Shaywanna, Lambie, Glenn, Hundley, Gulnora, Kelchner, Viki, Bai, Haiyan, University of Central Florida
- Abstract / Description
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College students diagnosed with Attention Deficit-Hyperactivity Disorder (ADHD) are at an increased risk of depression, anxiety, and lower academic self-efficacy as compared to college students not diagnosed with ADHD. Additionally, college students with ADHD diagnoses struggle to obtain effective treatment options for their ADHD symptoms. Specifically, pharmacological interventions are effective in mitigating ADHD symptoms; however, adverse effects of stimulant medications (i.e., increased...
Show moreCollege students diagnosed with Attention Deficit-Hyperactivity Disorder (ADHD) are at an increased risk of depression, anxiety, and lower academic self-efficacy as compared to college students not diagnosed with ADHD. Additionally, college students with ADHD diagnoses struggle to obtain effective treatment options for their ADHD symptoms. Specifically, pharmacological interventions are effective in mitigating ADHD symptoms; however, adverse effects of stimulant medications (i.e., increased/decreased appetite, headache) impact medication adherence in college students with ADHD. Neurofeedback is a non-invasive, drug-free intervention that uses the theories of biofeedback and cybernetics to increase self-regulation of brain functions. The purpose of this dissertation study was to examine differences in college student participants' scores on inattention, hyperactivity, impulsivity, self-concept, depression, anxiety, and self-efficacy measures over time when exposed to the neurofeedback intervention. The researcher employed a quasi-experimental, one group, time series design to explore differences in levels of symptomology in 11 participants over four assessment points. The results identified participants' scores in inattention (p = .016), hyperactivity (p = .017), self-concept (p = .008), depression (p = .004), and anxiety (p = .018) significantly decreased of the course of the intervention (16 neurofeedback sessions). Moreover, the participants' self-reported levels of academic self-efficacy increased significantly over time (p (<) .001). The findings for the current study provide practical, professional, and public policy implications, expanding the neurofeedback training and ADHD literature.
Show less - Date Issued
- 2017
- Identifier
- CFE0006600, ucf:51271
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006600
- Title
- Hyperactivity in attention-deficit/hyperactivity disorder (ADHD): Testing functional relationships with phonological working memory performance and attention.
- Creator
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Sarver, Dustin, Rapport, Mark, Beidel, Deborah, Mouloua, Mustapha, Vasquez, Eleazar, University of Central Florida
- Abstract / Description
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Excessive gross motor activity is currently considered a ubiquitous and disruptive feature of attention-deficit/hyperactivity disorder (ADHD); however, an alternative model challenges this premise and hypothesizes a functional relationship between activity level, attention, and working memory. The current study investigated whether, and the extent to which, particular forms of gross motor activity are functionally related to children's attention and phonological working memory performance....
Show moreExcessive gross motor activity is currently considered a ubiquitous and disruptive feature of attention-deficit/hyperactivity disorder (ADHD); however, an alternative model challenges this premise and hypothesizes a functional relationship between activity level, attention, and working memory. The current study investigated whether, and the extent to which, particular forms of gross motor activity are functionally related to children's attention and phonological working memory performance. Objective observations of children's gross motor movements and attention by independent observers were conducted while children with ADHD (n = 29) and typically developing children (n = 23) completed multiple counterbalanced tasks entailing low and high phonological working memory demand. The tasks were then sequenced hierarchically to reflect the lowest to highest activity level condition for each child. Results revealed that (a) ADHD-related phonological working memory performance deficits are moderated by increases in intra-individual activity level, (b) heightened activity level impacts performance independently of changes in observed attention, and (c) increases in particular forms of movement (foot movement and out-of-chair movement) contribute to greater phonological working memory performance within the context of attentive behavior. The findings collectively indicate that phonological working memory deficits in children with ADHD are associated with an inability to up-regulate motor activity to facilitate optimal task performance, and that behavioral treatments targeting reductions in certain forms of hyperactivity may have unintended consequences on working memory functioning in ADHD.
Show less - Date Issued
- 2013
- Identifier
- CFE0004930, ucf:49630
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004930
- Title
- HOW SYMPTOMS OF ANXIETY, DEPRESSION, ATTENTION DEFICIT DISORDER (ADD) OR ATTENTION DEFICIT HYPERACTIVITY DISORDER (ADHD) CONTRIBUTE TO STUDENTS SELF-MEDICATING VIA MARIJUANA AND NON-MEDICAL PRESCRIPTION DRUGS.
- Creator
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Thomas, Maria, Donley, Dr. Amy, University of Central Florida
- Abstract / Description
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This study examines student's nonmedical prescription drug (NMPD) and marijuana use and whether anxiety, depression, ADD or ADHD symptoms are associated with their use and if students are self-medicating to alleviate symptoms. The method of obtaining this information was provided by a total of 278 college students who voluntarily and anonymously completed a Web-based survey. This study fills in the gaps of previous research and reveals the most frequent NMPD's used by students and their...
Show moreThis study examines student's nonmedical prescription drug (NMPD) and marijuana use and whether anxiety, depression, ADD or ADHD symptoms are associated with their use and if students are self-medicating to alleviate symptoms. The method of obtaining this information was provided by a total of 278 college students who voluntarily and anonymously completed a Web-based survey. This study fills in the gaps of previous research and reveals the most frequent NMPD's used by students and their overall perceptions of their intended effects of the drug and answers why students do not seek professional help for their anxiety, depression and impulsivity symptoms. Results from the survey indicate that students who report NMPD use self- reported higher symptoms of anxiety, depression and impulsivity. NMPD users reported higher percentages of other substance abuse compared to nonusers. The most prominent NMPD's used by students are Adderall and Vicoden or Codeine. Data also indicates student's primary reasons for their NMPD use are related to academic purposes; as opposed to nonacademic. This analysis is further supported by the fact that the majority of NMPD users did not use before they began college and do not use while classes are not is session. Furthermore, students perceive their overall intended effects of their NMPD use to be beneficial, despite the known risks associated with their drug use. By examining college student's current NMPD use we can provide alternative solutions to students who are self-medicating as a coping mechanism for underlying issues or mental health disorders. Also, we can provide them with the necessary services in order to address their problems professionally.
Show less - Date Issued
- 2013
- Identifier
- CFH0004445, ucf:45114
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004445
- Title
- Effects of Signal Probability on Multitasking-Based Distraction in Driving, Cyberattack (&) Battlefield Simulation.
- Creator
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Sawyer, Benjamin, Karwowski, Waldemar, Hancock, Peter, Xanthopoulos, Petros, University of Central Florida
- Abstract / Description
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Multitasking-based failures of perception and action are the focus of much research in driving, where they are attributed to distraction. Similar failures occur in contexts where the construct of distraction is little used. Such narrow application was attributed to methodology which cannot precisely account for experimental variables in time and space, limiting distraction's conceptual portability to other contexts. An approach based upon vigilance methodology was forwarded as a solution, and...
Show moreMultitasking-based failures of perception and action are the focus of much research in driving, where they are attributed to distraction. Similar failures occur in contexts where the construct of distraction is little used. Such narrow application was attributed to methodology which cannot precisely account for experimental variables in time and space, limiting distraction's conceptual portability to other contexts. An approach based upon vigilance methodology was forwarded as a solution, and highlighted a fundamental human performance question: Would increasing the signal probability (SP) of a secondary task increase associated performance, as is seen in the prevalence effect associated with vigilance tasks? Would it reduce associated performance, as is seen in driving distraction tasks? A series of experiments weighed these competing assumptions. In the first, a psychophysical task, analysis of accuracy and response data revealed an interaction between the number of concurrent tasks and SP of presented targets. The question was further tested in the applied contexts of driving, cyberattack and battlefield target decision-making. In line with previous prevalence effect inquiry, presentation of stimuli at higher SP led to higher accuracy. In line with existing distraction work, performance of higher numbers of concurrent tasks tended to elicit slower response times. In all experiments raising either number of concurrent tasks or SP of targets resulted in greater subjective workload, as measured by the NASA TLX, even when accompanied by improved accuracy. It would seem that (")distraction(") in previous experiments has been an aggregate effect including both delayed response time and prevalence-based accuracy effects. These findings support the view that superior experimental control of SP reveals nomothetic patterns of performance that allow better understanding and wider application of the distraction construct both within and in diverse contexts beyond driving.
Show less - Date Issued
- 2015
- Identifier
- CFE0006388, ucf:51522
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006388
