The need for expedient detection of and response to signals of danger compels the development of sophisticated neural circuits for threat processing. This threat neural circuitry should support not only identification of and response to innately threatening stimuli, but also learning and memory of sensory cues predictive of such threats. While extensive rodent and human research has established an essential role of the amygdala in processing innate and learned threats, increasing evidence suggests the existence of extra-amygdala neural circuits that are capable of independent threat processing. The sensory cortex emerges as an important part of the threat circuitry, demonstrating heightened neural response to innately threatening stimuli and persistent neural plasticity as a result of threat learning. In three separate yet conceptually-integrated experiments, employing a combination of electrophysiological and functional magnetic resonance imaging (fMRI) methods, this dissertation examines threat processing in the human sensory cortex, and importantly, disentangles its unique contribution from that of the amygdala. Study 1 (Chapter 2) indicated that the ventral visual cortex was capable of fast, refined processing of threat scenes, relatively independent of the amygdala. Studies 2 and 3 (Chapters 3 and 4) further applied threat conditioning to examine possible learning and memory mechanisms by which the sensory cortex contributes to the processing of threat. Study 2 demonstrated immediate and long-term plastic changes in the olfactory cortex to learned threat odors, combining fMRI, olfactory aversive conditioning, and a long-term memory retention test (on Day 9). Lastly, Study 3 revealed visual cortical and amygdala contributions to immediate and lasting plastic changes to learned visual threats, respectively, combining brain electrophysiology, visual aversive conditioning, and a long-term memory retention test (on Day 16). Together, these three experiments demonstrate the critical role the sensory cortex plays in threat encoding and the origin of such sensory cortical threat codes via associative learning. / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester 2017. / September 20, 2017. / Fear conditioning, Long-term memory, Olfaction, Sensory cortex, Threat, Visual perception / Includes bibliographical references. / Wen Li, Professor Directing Dissertation; Mohamed Kabbaj, University Representative; Colleen M. Kelley, Committee Member; Zuoxin Wang, Committee Member; Jian Feng, Committee Member.

Perceiving our world is an active process. We actively explore and investigate the environment rather than passively registering the objects and events we encounter. Our perception and attention reflect our moods, expectations, and beliefs. Recent evidence supporting this approach comes from studies that focus on the impact of individual differences on human perception and attention. Characteristics about the world we live in, like culture or religion, may drive these differences in perception and attention. One of the ways this has been looked at is by examining executive functioning. Inhibitory control, the ignoring of irrelevant information, is an important component of executive functioning. The Simon, Flanker, and Stroop tasks are all common measures of inhibitory control. They all require to some degree the inhibition of irrelevant information when selecting an appropriate response to stimuli. Several studies have reported a bilingual advantage on these tasks. Previous research has indicated differences in cognitive functioning for those of different political beliefs. Differences are seen in perception of multi-level stimuli in people of different cultures and religions and for people with different political leanings. Previous research has found similar differences in performance on a measure of executive functioning for people of different religions. The expected effects for the Simon and Flanker task were found in this sample. Differences in the size of the Simon and Flanker effect were not found in this sample for those of different religious beliefs or political beliefs / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester 2017. / November 8, 2017. / Attention, Executive Functioning, Inhibitory control, Political beliefs, Religious beliefs, Simon effect / Includes bibliographical references. / Michael P. Kaschak, Professor Directing Dissertation; Gretchen Sunderman, University Representative; Walter Richard Boot, Committee Member; Colleen M. Kelley, Committee Member; Paul Conway, Committee Member.

This thesis examines the highly interlinked fields of voluntary action, apathy and option generation. Substantial research have now implicated the medial frontal cortex in voluntary actions, but the exact roles of each region remain unclear. Seeking clarity on this is important because the lack of self-generated behaviour is characteristic of apathy, a debilitating condition prevalent in neurodegenerative diseases and occurring to varying degrees in healthy individuals. Unfortunately, the conceptualization of apathy is currently unclear. Proposals of its underlying cognitive mechanisms have also mostly focused on deficits in selecting between options and learning outcomes during feedback. Intriguingly, the possibility that an inability to self-generate options may contribute to apathy has never been examined. This is because neuroscientific research on option generation is sparse. Here, a major contribution was the advancement of our understanding of option generation for behaviour. As there was no suitable objective measure available in the current literature, a simple, quantitative and culture-free task to assess option generation was first developed. The task was then administered to patients with Parkinson‖s disease and utilised in two pharmacological studies of dopamine agonist (cabergoline) and antagonist (haloperidol). These provided the first direct evidence that dopamine modulates option generation for behaviour in humans, specifically in the aspects of fluency (generating many options) and uniqueness (how different each option is from others). The ability to generate options was also found to associate with apathy in the healthy population. Besides that, the multidimensional structure of apathy was examined via the development and rigorous validation of a new questionnaire known as the Apathy Motivation Index. Finally, a functional neuroimaging experiment in healthy individuals revealed that the pre-supplementary motor area plays a key role in planning during volitional decisions of what action to execute. Together, these findings have provided new insights and point to new directions for future work in this field.

abstract: Interface design has a large impact on the usability of a system, and the addition of multitasking only makes these systems more difficult to use. Information processing, mental workload, and interface design are determining factors that impact the performance of usability, and therefore interface design needs to be more adapted to users undergoing a high mental workload. This study examines how a primary task, visual tracking, is affected by a secondary task, memory. Findings show that a high mental workload effects reaction time and memory performance on layouts with a high index of difficulty. Further research should analyze the effects of manipulating target size and distance apart independently from manipulating the index of difficulty on performance. / Dissertation/Thesis / Masters Thesis Human Systems Engineering 2018

abstract: The present study examined the effect of value-directed encoding on recognition memory and how various divided attention tasks at encoding alter value-directed remembering. In the first experiment, participants encoded words that were assigned either high or low point values in multiple study-test phases. The points corresponded to the value the participants could earn by successfully recognizing the words in an upcoming recognition memory task. Importantly, participants were instructed that their goal was to maximize their score in this memory task. The second experiment was modified such that while studying the words participants simultaneously completed a divided attention task (either articulatory suppression or random number generation). The third experiment used a non-verbal tone detection divided attention task (easy or difficult versions). Subjective states of recollection (i.e., “Remember”) and familiarity (i.e., “Know”) were assessed at retrieval in all experiments. In Experiment 1, high value words were recognized more effectively than low value words, and this difference was primarily driven by increases in “Remember” responses with no difference in “Know” responses. In Experiment 2, the pattern of subjective judgment results from the articulatory suppression condition replicated Experiment 1. However, in the random number generation condition, the effect of value on recognition memory was lost. This same pattern of results was found in Experiment 3 which implemented a different variant of the divided attention task. Overall, these data suggest that executive processes are used when encoding valuable information and that value-directed improvements to memory are not merely the result of differential rehearsal. / Dissertation/Thesis / Masters Thesis Psychology 2019

abstract: As automation becomes more prevalent in society, the frequency that systems involve interactive human-automation control increases. Previous studies have shown accountability to be a valuable way of eliciting human engagement and reducing various biases, but these studies have involved the presence of an authority figure during the research. The current research sought to explore the effect of accountability in the absence of an authority figure. To do this, 40 participants took part in this study by playing a microworld simulation. Half were told they would be interviewed after the simulation, and half were told data was not being collected. Eleven dependent variables were collected (accountability, number of resources shared, player score, agent score, combined score, and the six measures of the NASA- Task Load Index), of which statistical significance was found in number of resources shared, player score, and agent score. While not conclusive, the results suggest that accountability affects human-automation interactions even in the absence of an authority figure. It is suggested that future research seek to find a reliable way to measure accountability and examine how long accountability effects last. / Dissertation/Thesis / Masters Thesis Human Systems Engineering 2019

No description available.

No description available.

No description available.

No description available.