Doctor of Philosophy, The Ohio State University, 2006, Biophysics

Functional MRI was used to examine brain activation during language processing and the effect of L-Dopa on brain hemodynamics and language. Firstly, we wished to determine the effect of L-Dopa on brain hemodynamics. Since fMRI signal is based on cerebral blood flow, oxygenation and cerebral blood volume changes, drug administration could interfere with the coupling of neural activation with these parameters, independent of neuronal activity. To obtain this information a theoretical model of a relationship between BOLD signal and CBF was used. The results revealed no significant changes induced by drug in baseline CBF. Therefore, this was not used as a covariate in the subsequent studies of language. Secondly, we examined the semantic priming and dopamine effects on brain activation. We intended to implement a protocol for language function imaging, explore different paradigm designs in fMRI, and examine brain activation and the effect of L-Dopa. Behavioral measurements demonstrated a significant priming effect for all semantic distances. Imaging results showed activation in a network known to be involved in language processing and attention. The block and event related paradigms were explored and compared, revealing the importance of design selection in fMRI. No drug or temporal effects were found on the activation maps, suggesting that more sensitive techniques must be used to detect these changes. Lastly, fMRI was used to study functional connectivity associated with semantic and phonological processing. The goal was to explore the interaction between language network components and to determine if they are affected by administration of L-Dopa. Activation patterns for the two language processes were obtained and compared to previous findings. The functional connectivity, calculated as the correlation between the time series data of two brain areas was determined and revealed that language areas were activated more synchronously for phonological tasks than for sema (open full item for complete abstract)

Committee: David Beversdorf (Advisor) Subjects: Biophysics, General

Psy. D., Antioch University, 2013, Antioch Seattle: Clinical Psychology

This study investigated the early effects of the Tomatis Method, hypothesizing improvement in processing speed, phonological awareness, reading efficiency, attention, behavior and brain physiology by the end of Phase 1 of the Tomatis Method. This study documented the effects of the first phase of the Tomatis Method on children with ADD ages 7-13. Of the 25 participants, 15 received solely the Tomatis treatment while 10 served as controls and were stabilized on ADD medication three months prior to and throughout the study. Therefore, this research study compared Tomatis versus non-Tomatis intervention, not ADD medication treatment with Tomatis intervention. The Tomatis group received 15 consecutive 2 hour sessions; participants received no additional vestibular or visual-motor exercises throughout the research. Results revealed statistically significant improvements for the Tomatis when compared to the non-Tomatis group: the experimental group showed significant improvement in processing speed, phonological awareness, phonemic decoding efficiency when reading, behavior, and auditory attention. A statistically significant increase in slow brain activity at central and parietal midline recording sites in the Tomatis group was observed when comparing pre- and posttreatment theta/beta ratios within each group. Taken in isolation, these are paradoxical findings as they do not concur with the gains documented. The peak alpha frequency values and the z-scored theta/beta ratios of the pre- and post- qEEGs for each participant in the Tomatis group were further explored. The paradoxical increase in theta/betha ratios obtained from individual raw values were not observed to the same extent when using z-scores. The z-scores suggested that the theta/beta ratio, although higher for the Tomatis group after training, remains within the average range for all participants. The individual analysis showed that the changes observed still fell within normal values, which may se (open full item for complete abstract)

Committee: Alejandra Suarez PhD (Committee Chair); Maritza Rivera-Gaxiola PhD (Committee Member); Patricia Linn PhD (Committee Member) Subjects: Psychology

Doctor of Philosophy, Case Western Reserve University, 2022, Communication Sciences

Childhood Apraxia of Speech (CAS) is a developmental speech sound disorder (SSD) notable for its severity and persistence of speech difficulties. A debate has surfaced historically about the cause of the speech and language deficits observed in the disorder. As children with CAS often present with comorbid language problems (i.e., receptive and expressive), learning disabilities (i.e., reading and spelling), and fine and gross motor difficulties, any conceptualization of the disorder should include an accounting of the multiple domains affected. However, CAS has been primarily viewed as a motor-speech disorder affecting speech production with consequences for expressive language. While there is extensive research about the association between an early diagnosis of other idiopathic SSD and poorer literacy outcomes, there is limited research investigating this same association for CAS. Given the increased risk of reading disorder (RD) with other idiopathic SSD, a better understanding of this association for CAS is crucial for children with this diagnosis. This dissertation research investigated literacy and literacy-related skills in a group of children with an early diagnosis of CAS (n = 16), ranging in age from 8 to 14 years. Comparisons were made with a group of children in a similar age range with a diagnosis of reading disorder without any history of SSD (RD-no SSD, n = 16). Results suggest that many children with an early diagnosis of CAS share the same degree of difficulty with word-level decoding as those diagnosed with RD-no SSD. In contrast, the two groups' phonological processing abilities were significantly different. The CAS group scored below the normative mean for phonological awareness and phonological memory, and the RD-no SSD group obtained mean scores within the average range. Additionally, subgroups were identified within the CAS participant group by average and below-average word-level decoding fluency. Below-average decoding fluency was associa (open full item for complete abstract)

Committee: Barbara Lewis (Committee Chair) Subjects: Language; Reading Instruction; Speech Therapy

Doctor of Philosophy, The Ohio State University, 2017, Linguistics

Speakers adopt acoustic characteristics of others' speech, a process known as phonetic imitation, and they also maintain and generalize imitation to novel words to which they have not been exposed. Relatively little, however, is known about what factors influence imitation generalization and maintenance, especially for cross-category variants. This dissertation focused on imitation of dialect-specific segmental variants in Jianshi Mandarin, and aimed to address three main research questions: (i) the role of automaticity vs. speakers' control in mediating imitation generalization and maintenance; (ii) the levels of representational specificity at which cross-category imitation operates and generalizes, i.e., representations of monosyllabic words, syllables, phonemes, or features; and (iii) the relative contribution of exposure amount and variability to imitation generalization and maintenance beyond perceptual exposure. To explore the role of automaticity vs. speakers' control, three types of post-exposure reading instructions were used as a way of manipulating participants' conscious effort during post-exposure speech production: to read the words, to say the words like the person you heard, and to say the words in the way you normally say them. Participants consistently imitated the target variants during the shadowing block. In the post-exposure block, the most robust and consistent imitation generalization and maintenance effects were observed with the explicit imitation instruction. The read and not imitate instructions led to no or weak imitation generalization and maintenance, which were smaller in magnitude and consistency than in the imitation instruction condition. These results suggest that imitation generalization and maintenance involve both automatic and controlled aspects, and that speakers' control plays a primary role and automaticity is secondary in these processes. Regarding representational specificity involved in imitation generalization, (open full item for complete abstract)

Committee: Cynthia Clopper (Advisor); Kathryn Campbell-Kibler (Committee Member); Shari Speer (Committee Member) Subjects: Linguistics

Doctor of Philosophy, Case Western Reserve University, 1995, Psychology

The relationship between phonological skills and early reading is strong and well known. However, the causal nature of this relationship is unclear. This study examines possible constructs that may mediate the relationship between early reading and phonological processing. Using 86 kindergarten boys and girls, measures of intelligence, language, and memory were assessed as possible mediators. Using a technique called dominance analysis (Budescu, 1993), it was discovered that phonological skills were more closely associated with early reading recognition skills and letter sound knowledge than was IQ, language, and memory skills. Additionally, phonological skills were found to be more highly related to early reading skills than to mathematical ability. The implications of these findings are discussed.

Committee: Elizabeth Short (Advisor) Subjects: Education, Educational Psychology

Doctor of Philosophy (Ph.D.), Bowling Green State University, 2010, Psychology/Clinical

A well-established link between anxiety and impaired cognitive performance exists. Researchers have put forth several theories to explain the mechanisms of this relationship. Two such explanations are Cognitive Interference Theory (CIT) and Attentional Control Theory(ACT). The present study used a sample of 97 undergraduate students to test hypotheses made by both theories. Participants completed a demographic questionnaire and measures of state anxiety, evaluation anxiety, cognitive interference, and attentional control. They were randomly assigned to either an anxiety or a non-anxiety instruction condition and were then administered various cognitive tasks, which included measures of phonological loop, central executive, and visuospatial sketchpad functioning. The central executive tasks completed included measures of inhibition, switching, and updating. Results indicate that many CIT hypotheses were supported. Most notably, those receiving anxiety-inducing instructions experienced greater levels of evaluation anxiety and made more negative self-statements on a measure of cognitive interference. The anxiety condition was also associated with worse performance on measures of phonological loop and central executive, but not visuospatial sketchpad, functioning. Negative self-statements mediated the relationship between anxiety condition and performance on central executive tasks, accounting for approximately 23% of the variance in the relationship. Negative self-statements did not mediate the relationship between anxiety condition and phonological loop functioning, and accounted for very little of the variance in the relationship. Partial support was found for ACT. Specifically, measures of attentional control did not predict performance on central executive tasks. This held true for both measures of task effectiveness (errors made on the tasks) and task efficiency (time taken to complete tasks). The results were interpreted within both the CIT and ACT contexts. I (open full item for complete abstract)

Committee: William O'Brien Ph.D. (Advisor); Margaret Brooks Ph.D. (Committee Member); Robert Carels Ph.D. (Committee Member); Steve Jex Ph.D. (Committee Member) Subjects: Psychological Tests; Psychology