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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.
51

Warning a Distracted Driver: Smart Phone Applications, Informative Warnings and Automated Driving Take-Over Requests

January 2017 (has links)
abstract: While various collision warning studies in driving have been conducted, only a handful of studies have investigated the effectiveness of warnings with a distracted driver. Across four experiments, the present study aimed to understand the apparent gap in the literature of distracted drivers and warning effectiveness, specifically by studying various warnings presented to drivers while they were operating a smart phone. Experiment One attempted to understand which smart phone tasks, (text vs image) or (self-paced vs other-paced) are the most distracting to a driver. Experiment Two compared the effectiveness of different smartphone based applications (app’s) for mitigating driver distraction. Experiment Three investigated the effects of informative auditory and tactile warnings which were designed to convey directional information to a distracted driver (moving towards or away). Lastly, Experiment Four extended the research into the area of autonomous driving by investigating the effectiveness of different auditory take-over request signals. Novel to both Experiment Three and Four was that the warnings were delivered from the source of the distraction (i.e., by either the sound triggered at the smart phone location or through a vibration given on the wrist of the hand holding the smart phone). This warning placement was an attempt to break the driver’s attentional focus on their smart phone and understand how to best re-orient the driver in order to improve the driver’s situational awareness (SA). The overall goal was to explore these novel methods of improved SA so drivers may more quickly and appropriately respond to a critical event. / Dissertation/Thesis / Doctoral Dissertation Applied Psychology 2017
52

Neurobiological Mechanisms of Cognitive Maintenance and Disengagement: Accounting for Dissociable Variance in Working Memory and Fluid Intelligence Task Performance

January 2017 (has links)
abstract: Performance on working memory (WM) and fluid intelligence tasks (gF) is often highly correlated. However, recent research by Shipstead, Harrison, & Engle (2016) has suggested that dissociable cognitive processes underlie performance on WM and gF tasks, such that WM task performance is contingent upon maintenance of relevant information while gF task performance is contingent upon disengaging from irrelevant information so that updating can occur. The aim of the current study was to test the proposal that the dopamine gating system, a neurological mechanism underlying information encoding and updating, is a plausible mechanism underlying the abilities identified by Shipstead and colleagues that are separately unique to WM and gF. Sixty-three participants completed a task that measured ability to maintain and update information, and is neurologically known to reflect functionality of the dopamine gating system during updating performance. The results indicate that individual differences in updating performance are predicted by gF, but not by WM. This suggests that the ability to disengage from irrelevant information is facilitated by distinct processes in the dopamine gating system, and is a distinguishing component of gF. / Dissertation/Thesis / Masters Thesis Psychology 2017
53

Isolating Neural Reward-Related Responses via Pupillometry

January 2017 (has links)
abstract: Recent research has shown that reward-related stimuli capture attention in an automatic and involuntary manner, or reward-salience (Le Pelley, Pearson, Griffiths, & Beesley, 2015). Although patterns of oculomotor behavior have been previously examined in recent experiments, questions surrounding a potential neural signal of reward remain. Consequently, this study used pupillometry to investigate how reward-related stimuli affect pupil size and attention. Across three experiments, response time, accuracy, and pupil were measured as participants searched for targets among distractors. Participants were informed that singleton distractors indicated the magnitude of a potential gain/loss available in a trial. Two visual search conditions were included to manipulate ongoing cognitive demands and isolate reward-related pupillary responses. Although the optimal strategy was to perform quickly and accurately, participants were slower and less accurate in high magnitude trials. The data suggest that attention is automatically captured by potential loss, even when it is counterintuitive to current task goals. Regarding a pupillary response, patterns of pupil size were inconsistent with our predictions across the visual search conditions. We hypothesized that if pupil dilation reflected a reward-related reaction, pupil size would vary as a function of both the presence of a reward and its magnitude. More so, we predicted that this pattern would be more apparent in the easier search condition (i.e., cooperation visual search), because the signal of available reward was still present, but the ongoing attentional demands were significantly reduced in comparison to the more difficult search condition (i.e., conflict visual search). In contrast to our predictions, pupil size was more closely related to ongoing cognitive demands, as opposed to affective factors, in cooperation visual search. Surprisingly, pupil size in response to signals of available reward was better explained by affective, motivational and emotional influences than ongoing cognitive demands in conflict visual search. The current research suggests that similar to recent findings involving LC-NE activity (Aston-Jones & Cohen, 2005; Bouret & Richmond, 2009), the measure of pupillometry may be used to assess more specific areas of cognition, such as motivation and perception of reward. However, additional research is needed to better understand this unexpected pattern of pupil size. / Dissertation/Thesis / Masters Thesis Psychology 2017
54

Do Peripheral HUD Warnings Affect Driving Ability?

Knarr, Abram J. 04 May 2018 (has links)
<p> Heads Up Display (HUD) technologies are being developed to assist drivers and reduce safety hazards. The current study used the Lane Change Task (LCT) and a Peripheral Detection Task (PDT) divided into high and low workload tracks to assess effects of employing a HUD to alert drivers to moving objects in their periphery that are possible hazards. The intent of the current study was to determine whether visual warnings displayed in either color, flashing, or color and flashing formats, would improve detection of moving stimuli without adversely impacting driving ability. Results indicated that the PDT had no significant effect on LCT performance. However, significant main effects of warning format and workload on reaction times, false alarm rates, and sensitivity were obtained. Performance on the PDT task was best when the warnings were non-flashing and yellow, especially in the low workload condition. Explanations of performance on both tasks are discussed.</p><p>
55

Response-Effect Compatibility Defines the Natural Zooming Direction with Indirect Manipulation Devices

Winter, Alice Bellemin 10 May 2018 (has links)
<p> Zooming is a type of user interaction offered by many programs and devices. It is used by millions of people, particularly with interactive web maps, but very few experiments have investigated why certain implementations are more effective than others. Research with direct manipulation devices (e.g., touchscreens) has found that the most natural user interaction is to swipe their finger in the direction they wish content to move. However, the most intuitive zooming direction is ambiguous for indirect manipulation devices (e.g., mouse, touchpad, and keyboard). Additionally, it is even less obvious which directional movement would result in a zooming gesture since most indirect manipulation devices only permit X and Y movements and zooming is a Z movement. For this reason, the current study investigated which Y axis directional movement is most compatible with zooming (a movement along the Z dimension) on indirect manipulation devices, and if this mapping is influenced by response method, depth cues, or instructions. Our results indicated that the R-E compatible zooming direction on indirect manipulation devices is what we define as the Forward in | Backward out mapping, which means the participant is moving their finger forward to zoom in and moving it backward to zoom out. This was reflected in higher accuracy for both touchpads and buttons and faster reaction times with touchpads. This suggests that the action of zooming on a 2D display is conceptualized as moving forward in space.</p><p>
56

The Benefits of Testing| Individual Differences Based on Student Factors

Robey, Alison Marie 19 September 2017 (has links)
<p> The testing effect, the notion that retrieval practice compared to restudying information leads to greater and longer retention, is one of the most robust findings in cognitive science. However, not all learners experience a benefit from retrieval practice. Many manipulations that influence the benefits of the testing effect have been explored, however, there is still much to learn about potential individual differences in the benefits of retrieval practice over restudy. As the testing effect grows in popularity and increasing numbers of classrooms begin implementing retrieval practice, it is essential to understanding how students&rsquo; individual differences and cognitive abilities contribute to the effect. For my dissertation, I explore how students&rsquo; cognitive abilities, specifically, episodic memory, general fluid intelligence, and strategy use, relate to the benefit of retrieval practice. In Study 1, I developed a new measure to simultaneously capture two aspects of strategy use: variation in what strategies learners use and variation in how learners use strategies. In Study 2, I examine how these two types of strategy use, along with episodic memory and general fluid intelligence can be used to predict the magnitude of the testing effect. Converging evidence from multiple analyses suggests variation in how learners use strategies was the only individual difference to influence the benefit learners receive from retrieval practice. More specifically, learners who are less adaptive and flexible in their strategy use show a greater benefit than more skilled strategy users. These findings have implications both for improving existing theories of the mechanisms of the testing effect and for determining how to best incorporate retrieval practice into classroom settings.</p><p>
57

A study of some aspects of mental skill in the performance of laboratory and industrial tasks

Beishon, John January 1966 (has links)
No description available.
58

Understanding occlusion inhibition: A study of the visual processing of superimposed figures

Chambers, Destinee L 01 January 2009 (has links)
This study investigates a phenomenon that I have termed occlusion inhibition. This research and a small number of earlier studies suggest that, in some experimental conditions, when an attended (target) object is partially occluded by a distractor object, there is less attention allocated to the occluded region of the target object than to the visible parts of that object. In the literature, there are mixed results concerning this attentional effect. Some studies find it and others do not. This study investigates the differences between those conflicting studies with the goal of identifying the factor or factors that govern when occlusion inhibition occurs. Evidence is presented to rule out a number of potentially relevant factors such as depth perception, figural complexity, set size, the use of real world vs. abstract geometric objects, the position of occlusion, the number of overlaps in the display, and the adoption of the attend-object paradigm over the spatial cueing paradigm. After all these factors are ruled out, Experiments 3 and 4 provide evidence for a factor that does determine whether occlusion inhibition occurs or not. These two experiments differ only in the fact that participants are required to report the border color of the target object in Experiment 3 and not in Experiment 4. This task was designed to ensure that participants fully attend to the target object. Occlusion inhibition occurs when the target color is reported, but not when no target color report is required. Removing the target reporting task was found to be an effective means of turning occlusion inhibition on and off. The results of these experiments suggest that, if occlusion inhibition is to take place, attentional selection of overlapping figures requires the target object to be fully processed. This conclusion in turn suggests that attention does not automatically exclude the irrelevant portions of occluded objects, but that attention selects the entire location of the object and then, through reiterative feedback mechanisms, fine tunes the information to inhibit areas that do not belong to the object.
59

Why is it difficult to search for two colors at once? How eye movements can reveal the nature of representations during multi-target visual search

Stroud, Michael J 01 January 2010 (has links)
Visual search consists of locating a known target amongst a field of distractors. Often times, observers must search for more than one object at once. Eye movements were monitored in a series of visual search experiments examining search efficiency and how color is represented in order to guide search for multiple targets. The results demonstrated that observers were very color selective when searching for a single color. However, when searching for two colors at once, the degree of similarity between the two target colors had varying effects on fixation patterns. Search for two very similar colors was almost as efficient as search for a single color. As this similarity between the targets deceased, search efficiency suffered, resulting in more fixations on objects dissimilar to both targets. In terms of representation, the results suggest that the guiding template or templates prevailed throughout search, and were relatively unaffected by the objects encountered. Fixation patterns revealed that two similarly colored objects may be represented as a single, unitary range containing the target colors as well as the colors in between in color space. As the degree of similarity between the targets decreased, the two targets were more likely to be represented as discrete separate templates.
60

Binary rocs and their implications for the measurement of memory

Dube, Chad M 01 January 2011 (has links)
Bröder and Schütz (2009) have argued that the curvature typically observed in recognition memory receiver-operating characteristics (ROCs) is a by-product of the ratings task often used to obtain them. According to those authors, ROCs collected by experimentally manipulating response bias are linear and consistent with the assumptions of threshold and multinomial processing tree (MPT) models. Two experiments are reported which are broadly consistent with previous work by Dube and Rotello (under review) in showing that ROCs are curved and consistent with signal detection theory (SDT) regardless of the procedure used to obtain them. These results have implications for how accuracy is measured in tasks requiring binary responses. It is suggested that the use of statistics consistent with the assumptions of threshold models (e.g. percent correct, hits minus false alarms) should be avoided, as they are likely to produce statistical errors in several areas of the literature where ROCs have been found to be curved (Rotello, Masson, & Verde, 2008; Dube, Rotello, & Heit, 2010; 2011). SDT-based measures and ROC analysis are recommended to complement or replace analyses based on threshold statistics.

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