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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Subjective Measures of Implicit Categorization Learning

Zlatkin, Audrey 01 January 2019 (has links)
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 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.
12

The Effects of Presence and Cognitive Load on Episodic Memory in Virtual Environments

Barclay, Paul 01 January 2019 (has links)
Episodic memory refers to an individual's memory for events that they have experienced in the past along with the associated contextual details. In order to more closely reflect the way that episodic memory functions in the real world, researchers and clinicians test episodic memory using virtual environments. However, these virtual environments introduce new interfaces and task demands that are not present in traditional methodologies. This dissertation investigates these environments through the lenses of Presence and Cognitive Load theories in order to unravel the ways that basic technological and task differences may affect memory performance. Participants completed a virtual task under High and Low Immersion conditions intended to manipulate Presence and Single-Task, Ecological Dual-Task and Non-Ecological Dual-Task conditions intended to manipulate cognitive load. Afterward they completed a battery of memory tasks assessing spatial, object, and feature binding aspects of episodic memory. Analysis through 2x3 ANOVA showed that performance for spatial memory is greatly improved by manipulation of Presence, where performance for object memory is improved by germane cognitive load. Exploratory analyses also revealed significant gender differences in spatial memory performance, indicating that improving Presence may offset the higher levels in male performance traditionally seen on spatial tasks. These results have practical implications for clinical memory assessment, as well as training paradigms and may serve to highlight the differences in the ways that memory is studied in the laboratory versus the way that it is employed in day-to-day life. Future studies based on this research should focus on linking these differences in memory performance to visuospatial and verbal strategies of memorization and determining whether the effects observed in this study replicate using other manipulations of presence and cognitive load.
13

Threatening Instructions During a Hurricane Influence Risk Perceptions: The Case of Fear Appeals and Changing Hurricane Projections

Whitmer, Daphne 01 May 2019 (has links)
The goal of this research was to examine the effectiveness of persuasive language in the protective action recommendation of an emergency warning, which instructs people how to prepare and stay safe. Study 1 was a pilot study, which suggested that participants were able to make distinctions between hurricane categories. In study 2, the presence of fear language and second-person personal pronouns (i.e., "you") in a recommendation was manipulated. Overall, fear language was more influential than a pronoun on risk perceptions. To understand how context influences risk perceptions, participants in study 3 made decisions after each piece of information received. The severity of the hurricane increased, decreased, or stayed the same before decision point 2 and a recommendation containing fear or neutral language was presented before decision point 3. Those who read the fear message were more likely to be in the danger control process than those in the neutral language condition, which suggested that the fear message emphasized threat but did not diminish participants' perception of efficacy. Behavioral compliance with the warning was high in all conditions. In terms of change in perceived threat from decision point 2 to 3, participants in the decrease condition who read the fear appeal had the largest increase in perceived threat. In contrast, the hurricane increasing in intensity may be fear provoking enough that a fear appeal does not enhance risk perceptions. When examining individual differences, high Need for Cognition women had the largest increase in perceived message persuasiveness in the decrease and increase conditions. Phrasing guidelines for emergency management are discussed, along with the theoretical contributions of using social psychological methodology to examine emergency warnings. While individual differences are important predictors of warning interpretation, future research needs to reconcile the conundrum of emergency management's current limitations regarding individualized warnings.
14

If a Virtual Tree Falls in a Simulated Forest, is the Sound Restorative? An Examination of the Role of Level of Immersion in the Restorative Capacity of Virtual Nature Environments

Michaelis, Jessica 01 January 2019 (has links)
Stress and cognitive fatigue have become a pervasive problem, especially in Western society. Stress and cognitive fatigue can have deleterious effects not only on performance, but also on one's physical and mental health. This dissertation presents a study in which the aim is to investigate the effects of virtual nature on stress reduction and cognitive restoration. Specifically, this study assessed the effects of Immersion (Non-immersive, Semi-immersive, Fully-immersive) and Exploration (Passive vs Active) on stress reduction and cognitive restoration. Additionally, restoration from the most effective virtual nature environment was compared to that of taking an active coloring break. Eighty-three university students with normal color vision, depth perception and good visual acuity participated in this study. The overall findings of the study suggest that virtual nature is able to reduce stress and anxiety, generally the more immersive and interactive the better. Moreover, though both the those in the passive VR nature condition and those in the coloring condition reported a reduction in stress, only those in the passive VR nature condition exhibited the physiological changes indicative of stress reduction.
15

Human Factor Effects of Simulating Battlefield Malodors in Field Training

Pike, William 01 January 2018 (has links) (PDF)
In order to explore how to better utilize simulated odors for live training, a study of 180 United States Military Academy at West Point cadets was undertaken to determine whether pre-exposure to a simulated malodor may result in an amelioration of performance issues, as well as improving performance of a complex task. Exposure to malodors has long been shown to increase stress and escape behavior, and reduce performance of complex tasks, in addition to degrading other human factor areas. However, desensitization to a particular odor through a process known as olfactory adaptation, could ameliorate these performance issues. In this study, cadets were assigned to one of three conditions: Adaptation (odor/odor, to denote presence or absence of the simulated malodor in each of two phases), No Adaptation (no odor/odor), or Control (no odor/no odor). Participants wore a device to track electrodermal activity, a predictor of stress. Participants spent 12 minutes in a tent taking a quiz involving a common military task. After two minutes, a scent delivery system was turned on, delivering either the simulated malodor (burnt human flesh) or no odor. Participants exited the tent after the full 12 minutes and rated the air quality of the tent. They repeated the exercise in a second tent, with a similar quiz. Metrics of interest included perceived intensity and detection time, common metrics for gauging olfactory adaption, as well as electrodermal activity, escape behavior, and task performance. Results indicate participants in the Adaptation condition were partially desensitized to the malodor. Performance metrics did not show any statistical significance for stress, escape behavior, or performance improvement for the Adaptation condition, although there was a strong negative correlation of performance and perceived mental demand. Performance improvement and stress results were trending in the expected directions. This study differed from previous work in olfactory adaptation studies by linking adaptation to performance during a relevant complex task, and provides valuable lessons for future olfactory studies. From a more applied viewpoint, this study also provides insight for future research into the incorporation of malodors in live training.
16

The Effects of Social Conformity in Human-Robot Interaction

Volante, William 01 January 2020 (has links) (PDF)
While previous work has investigated aspects of the robot, the human, and the environment as influential factors in the human-robot relationship, little work has examined the role of social conformity in this relationship. As social conformity has been shown to affect human-human choice, relationships, and trust, there are a-priori reasons to believe that it will play an influential role in human-robot interaction (HRI) scenarios as well. Early research into the influence of social conformity in human-robot interaction (HRI) did not find the effect to be present with robots, however more recent work has adapted the methodological paradigm to find more consistent evidence of conformity in HRI settings. Here two studies investigated the impact of response methods (e.g., the ability to change your response), task types (i.e., arithmetic or line discriminations) and task importance on conformity with robots. Previous research has demonstrated conformity effects with the change response technique but not with the ordered response technique in HRI research. The first experiment aimed to specifically quantify the distinction in methodological change that has resulted in the conformity effect. This was done by examining both the task and response methods used. The second experiment aimed to add to the body of literature on the impact of task importance on conformity in HRI. While task importance has been shown to increase conformity in human-human research settings, this has yet to be specifically examined in HRI conformity research. Results from Experiment 1 show that a conformity effect is present with humans but not robots in the change response condition under certain task settings. Results from Experiment 2 indicate a pattern of conformity with robots but not humans during high importance tasks. These findings are discussed in relation to the body of literature on conformity and HRI settings as a whole.
17

The Cry-Wolf Phenomenon and its Effect on Alarm Responses

Bliss, James P. 01 January 1993 (has links) (PDF)
Responses to alarms are assumed important. Yet failure to respond to alarms is recognized, although is not well understood or quantified. Conditions that might induce a failure to respond include alarm unreliability (i.e., numerous false alarms, the "cry-wolf" effect), high primary task demand, or low criticality of the alarm itself. The goals of this research were to substantiate the existence of the cry-wolf effect, quantifying its effect on operator performance, and to examine the relation between the cry-wolf effect and alarm criticality. One hundred thirty-eight UCF students alternatively performed two primary tasks, chosen from the Automated Performance Test System. Subjects were presented alarms of varying reliabilities (25%, 50%, and 75 % true alarms) and urgencies (low, medium, and high) in three experimental blocks. A series of repeated-measures MANOVAs assessed the effects of increasing alarm reliability, criticality, and performance block on alarm response and primary task performance. A post-experimental questionnaire also provided correlational data to determine relationships between demographic and opinion items and alarm response performance. The results indicate that most subjects (about 90%) do not respond to all alarms but match their response rates to the expected probability of true alarms (probability matching). Further, alarm criticality and primary task difficulty modestly but significantly alter response rates, and the speed and accuracy of responding. About 10% of the subjects responded in the extreme, utilizing an all-or-none strategy. Implications of these results for alarm design instruction and further research are discussed.
18

Eye Movements and Spatial Ability: Influences on Thinking During Analogical Problem Solving

Schroeder, Bradford 01 January 2018 (has links)
Classic studies have examined the factors that influence the way in which people can solve difficult "insight" problems, which require creative solutions. Recent research has shown that guiding one's eye movements in a pattern spatially congruent with the solution improves the likelihood of formulating a spatial solution. The authors in this line of research argued that guiding eye movements in a pattern spatially equivalent to the solution of the problem yields an embodied cognitive benefit that aids problem solving. Specifically, guiding eye movements leads to the generation of a mental representation containing perceptual information that helps a problem solver mentally simulate the problem features, increasing likelihood to generate a solution to the problem. However, evidence from a small but critically relevant area of research supports that this embodied effect may be more simply a creativity-priming effect. The proposed research aimed to disentangle these ideas while addressing other research questions of interest: do embodied problem solving benefits transfer to later problem solving? Do individual differences in spatial ability influence how people solve these problems? The present study combined previously established methodologies in problem solving and analogical problem solving to investigate these research questions. Results of the present work tentatively support the embodied priming effect, mediated by a creativity-priming effect that influences problem solving performance. Both effects emerged after manipulating problem solvers' eye movements. There is also modest support for a link between spatial ability and analogical problem solving, but not initial problem solving. These results are interpreted through the lens of embodied cognitive theory, providing tentative support that guiding eye movements can influence reasoning through an enhancement of creativity.
19

The Perceptual and Decisional Basis of Emotion Identification in Creative Writing

Williams, Sarah 01 January 2019 (has links)
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 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.
20

Neural Dynamics of Categorical Representations Used for Visual Search

Phelps, Ashley 01 January 2023 (has links) (PDF)
Decades of visual attention research have predominantly used pictorial search paradigms that cue participants with the exact perceptual details of the target. However, in everyday life, people often search for categories rather than specific items (i.e., any pen rather than a specific pen). To study visual attention in a more realistic context, researchers can use categorical search paradigms that cue participants with text indicating the target category. In these instances, one must rely on long-term memory to retrieve categorical features of the target. Both experiments in this study were a reanalysis of experiments previously designed and collected by Schmidt and colleagues at Stony Brook University. In Experiment One, participants completed a pictorial or categorical search. Eye movements were used to assess search performance and electrophysiological data were assessed in response to the target cue and RI before search to evaluate the encoding and maintenance of the target. Although participants in the categorical condition were slower and exhibited weaker guidance, as measured by initial saccade direction (to the target, strong; to a distractor, weak), no differences in power or synchronous activity were observed when compared across target cue types. However, when the data were separated by guidance (strong or weak), categorical cues produced significantly more frontal-posterior theta synchrony before good guidance trials compared to bad guidance trials. In Experiment Two, participants were given categorical and specific text cues (i.e., the text always corresponded to a single target item). Specific text cues were expected to behave similarly to pictorial cues because participants knew the exact target features. Whereas specific text cues resulted in superior search performance across several measures, minimal neural differences were observed. The results from Experiment One implicate frontal-posterior theta synchrony as a potential neural marker of categorical information used to direct attention during visual.

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