One enduring question in the study of speech concerns the nature of the link between speech perception and production. Although accumulating evidence suggests that these two facets of spoken language are tightly coupled, the cognitive structure and neural organization underlying the interactions between the two processes are not well understood. In this thesis, I focus on questions that arise from observations related to when individuals are both talking and listening, and assess the sensitivity of talkers and listeners to the same change in the acoustics of speech. First, I aim to elucidate the neural substrates of auditory feedback control during vocalization by examining the brain response to acoustic perturbations towards auditory concomitants of speech using functional magnetic resonance imaging (fMRI) (Chapters 2 and 3). I demonstrate, for the first time, an extensive network of brain regions involved in the detection and correction of auditory feedback errors during speech production, for which three functionally differentiated neural systems can be delineated. Then I set out to address the online perception of own voice identity as individuals are talking. Chapters 4 and 5 measure the perceptual sensitivity of individuals to the auditory concomitants of their own speech by presenting temporally gated auditory feedback in stranger’s voices during talking. The results show that people perceive stranger’s voices as a modified version of their own voice and adjust their vocal production accordingly, when their utterances and heard feedback are phonetically congruent. Chapter 6 further examines this perceptual effect by using experimental paradigms in the domain of body ownership and shows that the misattribution of the stranger’s voice, is not predicted by individual differences in suggestibility; rather it is related to the integration of multimodal cues. In summary, by focusing on how the acoustics of speech are simultaneously processed for both the perception and production sides of spoken language, the series of studies add significantly to our understanding of the psychophysical, cognitive and anatomical relationships between speech perception and production, and are relevant to a wide range of clinical pathologies (e.g., stuttering, schizophrenia). / Thesis (Ph.D, Neuroscience Studies) -- Queen's University, 2012-08-29 10:08:57.516

Thesis (Ph. D.)--Georgia State University, 2007. / Title from file title page. George Pullman, committee chair; Marti Singer, Lyneé Gaillet, committee members. Electronic text (235 p. : ill. (some col.)) : digital, PDF file. Description based on contents viewed Nov. 14, 2007. Includes bibliographical references (p. 228-235).

Thesis (Ph. D.)--University of Oregon, 2007. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 173-184). Also available for download via the World Wide Web; free to University of Oregon users.

The prevalence of procrastination in the college environment is extremely high with estimates that 80–90% of college students procrastinate when completing academic tasks. Since it impacts the majority of college students, early identification of an individual’s personality traits and behavioral delay discounting tendencies that may contribute to academic procrastination can lead to improved productivity and overall, a better college experience. The present study reviews what is already known about the relationships between personality and delay discounting with academic procrastination. Based on the review of the current literature, this study strives to reinforce and extend what is known about the relationships between these variables, improve the methodology used to examine these relationships, and provide a possible neural basis of procrastination. The proposed study will be conducted with first-year undergraduate student participants who attend Scripps College, over three academic terms (three participant samples). The study materials consist of two self-report personality measures (Myers-Briggs Type Indicator and Revised NEO Personality Inventory), a delay discounting task involving choices between hypothetical monetary rewards, and two measures of academic procrastination: a self-report measure (Procrastination Assessment Scale—Students) and a behavioral measure through course assignment submission. The study predicts that the typical academic procrastinator is introverted, perceptive, neurotic, and impulsive. In addition, an academic procrastinator has tendencies toward poor self-discipline, non-conscientious behavior, and preferences for discounted future rewards. Limitations of this study and future directions are also discussed.

In the last decade, tremendous advances have been made in the effort to understand mind wandering, yet many questions remain unanswered. Chief among them is how mind wandering relates to learning. Insofar as mind wandering has been linked to poor learning, finding ways to reduce the propensity to mind wander could potentially improve learning. Two experiments were conducted to examine this. The first experiment evaluated how difficulty of the to-be-learned materials affected one’s tendency to mind wander and revealed that people mind wandered when there was a mismatch between their level of expertise and the difficulty of materials studied. The second experiment compared whether participants were more likely to mind wander in blocked or interleaved conditions and showed that participants were more likely to mind wander when materials were presented in a blocked fashion. Together, these results indicate that techniques such as studying materials specific to one’s own level of mastery or changing the way in which one studies might reduce mind wandering and improve learning. Of equal importance is the question of what happens on in the brain when a person mind wanders. While the effect of mind wandering on early sensory processing is known, the impact it has on learning-related processing is not. In two event-related potential (ERP) experiments, participants were asked to report whether they were mind wandering or not while studying materials they were later tested on. Analyses revealed that elaborative semantic processing – indexed by a late, sustained slow wave that was maximal at posterior parietal electrode sites – was attenuated when participants mind wandered. Crucially, the pattern when people were on task rather than mind wandering was similar to the subsequent memory effect previously reported by other memory researchers, suggesting that mind wandering disrupts the deep level of processing required for learning.

Abstract not available

The present study is a novel investigation of neural mechanisms underlying reading development in bilingual children compared to monolinguals. We asked how do bilingual children learn to read when faced with phonological processing across two languages? Both behavioral measures and functional Near Infrared Spectroscopy (fNIRS) were used to observe any similarities or differences in brain activity between bilingual and monolingual readers. The behavioral findings corroborate a bilingual reading advantage; bilinguals were faster and more accurate than monolinguals when reading words. fNIRS data showed bilinguals demonstrated greater activation in classic language areas as compared to monolinguals. Taken together, this research advances contemporary scientific controversy concerning types of processing underlying reading and its maturational development over time. Ultimately, this research may have translational significance in education to situate normative developmental reading milestones in bilingual children, which is vitally important in developing effective therapies for bilingual children at risk for reading disorders.

Impaired social interaction is one of the hallmarks of autism spectrum disorders (ASDs). Emotional faces are arguably the most critical visual emotional stimuli and the ability to perceive, recognize, and interpret emotions is central to social interaction and communication as well as healthy development. There is however, a paucity of studies devoted to neural and cognitive mechanisms underlying emotional face processing in adolescents with ASD. Through an implicit emotional face processing task completed in the MEG, we examined spatiotemporal differences in neural activation during angry and happy emotional face processing. Results suggest atypical frontal involvement in ASD adolescents during angry and happy face processing. In particular, orbitofrontal activation in participants with ASD was found to be delayed but greater in amplitude, relative to controls.

The present study is a novel investigation of neural mechanisms underlying reading development in bilingual children compared to monolinguals. We asked how do bilingual children learn to read when faced with phonological processing across two languages? Both behavioral measures and functional Near Infrared Spectroscopy (fNIRS) were used to observe any similarities or differences in brain activity between bilingual and monolingual readers. The behavioral findings corroborate a bilingual reading advantage; bilinguals were faster and more accurate than monolinguals when reading words. fNIRS data showed bilinguals demonstrated greater activation in classic language areas as compared to monolinguals. Taken together, this research advances contemporary scientific controversy concerning types of processing underlying reading and its maturational development over time. Ultimately, this research may have translational significance in education to situate normative developmental reading milestones in bilingual children, which is vitally important in developing effective therapies for bilingual children at risk for reading disorders.

Impaired social interaction is one of the hallmarks of autism spectrum disorders (ASDs). Emotional faces are arguably the most critical visual emotional stimuli and the ability to perceive, recognize, and interpret emotions is central to social interaction and communication as well as healthy development. There is however, a paucity of studies devoted to neural and cognitive mechanisms underlying emotional face processing in adolescents with ASD. Through an implicit emotional face processing task completed in the MEG, we examined spatiotemporal differences in neural activation during angry and happy emotional face processing. Results suggest atypical frontal involvement in ASD adolescents during angry and happy face processing. In particular, orbitofrontal activation in participants with ASD was found to be delayed but greater in amplitude, relative to controls.