Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
Displaying 11 - 20 of 84
Description
Distorted vowel production is a hallmark characteristic of dysarthric speech, irrespective of the underlying neurological condition or dysarthria diagnosis. A variety of acoustic metrics have been used to study the nature of vowel production deficits in dysarthria; however, not all demonstrate sensitivity to the exhibited deficits. Less attention has been paid to quantifying the vowel production deficits associated with the specific dysarthrias. Attempts to characterize the relationship between naturally degraded vowel production in dysarthria with overall intelligibility have met with mixed results, leading some to question the nature of this relationship. It has been suggested that aberrant vowel acoustics may be an index of overall severity of the impairment and not an "integral component" of the intelligibility deficit. A limitation of previous work detailing perceptual consequences of disordered vowel acoustics is that overall intelligibility, not vowel identification accuracy, has been the perceptual measure of interest. A series of three experiments were conducted to address the problems outlined herein. The goals of the first experiment were to identify subsets of vowel metrics that reliably distinguish speakers with dysarthria from non-disordered speakers and differentiate the dysarthria subtypes. Vowel metrics that capture vowel centralization and reduced spectral distinctiveness among vowels differentiated dysarthric from non-disordered speakers. Vowel metrics generally failed to differentiate speakers according to their dysarthria diagnosis. The second and third experiments were conducted to evaluate the relationship between degraded vowel acoustics and the resulting percept. In the second experiment, correlation and regression analyses revealed vowel metrics that capture vowel centralization and distinctiveness and movement of the second formant frequency were most predictive of vowel identification accuracy and overall intelligibility. The third experiment was conducted to evaluate the extent to which the nature of the acoustic degradation predicts the resulting percept. Results suggest distinctive vowel tokens are better identified and, likewise, better-identified tokens are more distinctive. Further, an above-chance level agreement between nature of vowel misclassification and misidentification errors was demonstrated for all vowels, suggesting degraded vowel acoustics are not merely an index of severity in dysarthria, but rather are an integral component of the resultant intelligibility disorder.
ContributorsLansford, Kaitlin L (Author) / Liss, Julie M (Thesis advisor) / Dorman, Michael F. (Committee member) / Azuma, Tamiko (Committee member) / Lotto, Andrew J (Committee member) / Arizona State University (Publisher)
Created2012
Description
Adverse childhood family environments have been found to have long-term effects on a child's well-being. Although no prior studies have examined the direct effects of childhood family adversities on nighttime blood pressure (BP) dip, parental death and divorce in childhood, have been associated with a variety of related psychological problems in adulthood. The current study examined the direct effects of parental death and divorce in childhood and quality of early family relationships on adult nighttime BP dip as well as the mediating role of three psychosocial factors (depression, hostility and social stress). One hundred and forty-three young adults were asked to complete self-reported measures of the three psychosocial factors and quality of family relationships. Study participants wore an ambulatory blood pressure (ABP) monitor over a 24-hr period in order to assess nocturnal BP dip. Although neither childhood family adversity nor quality of childhood family relationships directly predicted nighttime BP dipping, quality of early family relationships predicted all three psychosocial factors, and hostility was found to mediate the relationship between quality of childhood family relationships and nighttime systolic BP dip. Early family experiences play an important role in influencing nighttime cardiovascular functioning by influencing an individual's psychological functioning in young adulthood. Because nighttime non-dipping has been associated with increased risk for cardiovascular disease and other serious health conditions, the results of the present study have important clinical implications and provide specific psychosocial pathways that may be targeted in future programs designed to prevent and treat cardiovascular disease.
ContributorsTanaka, Rika (Author) / Luecken, Linda J. (Thesis advisor) / Wolchik, Sharlene (Committee member) / Davis, Mary (Committee member) / Arizona State University (Publisher)
Created2012
Description
In rehabilitation settings, activity limitation can be a significant barrier to recovery. This study sought to examine the effects of state and trait level benefit finding, positive affect, and catastrophizing on activity limitation among individuals with a physician-confirmed diagnosis of either Osteoarthritis (OA), Fibromyalgia (FM), or a dual diagnosis of OA/FM. Participants (106 OA, 53 FM, and 101 OA/FM) who had no diagnosed autoimmune disorder, a pain rating above 20 on a 0-100 scale, and no involvement in litigation regarding their condition were recruited in the Phoenix metropolitan area for inclusion in the current study. After initial questionnaires were completed, participants were trained to complete daily diaries on a laptop computer and instructed to do so a half an hour before bed each night for 30 days. In each diary, participants rated their average daily pain, benefit finding, positive affect, catastrophizing, and activity limitation. A single item, "I thought about some of the good things that have come from living with my pain" was used to examine the broader construct of benefit finding. It was hypothesized that state and trait level benefit finding would have a direct relation with activity limitation and a partially mediated relationship, through positive affect. Multilevel modeling with SAS PROC MIXED revealed that benefit finding was not directly related to activity limitation. Increases in benefit finding were associated, however, with decreases in activity limitation through a significant mediated relationship with positive affect. Individuals who benefit find had a higher level of positive affect which was associated with decreased activity limitation. A suppression effect involving pain and benefit finding at the trait level was also found. Pain appeared to increase the predictive validity of the relation of benefit finding to activity limitation. These findings have important implications for rehabilitation psychologists and should embolden clinicians to encourage patients to increase positive affect by employing active approach-oriented coping strategies like benefit finding to reduce activity limitation.
ContributorsKinderdietz, Jeffrey Scott (Author) / Zautra, Alex (Thesis advisor) / Davis, Mary (Committee member) / Barrera, Manuel (Committee member) / Okun, Morris (Committee member) / Arizona State University (Publisher)
Created2012
Description
Otoacoustic emissions (OAEs) are soft sounds generated by the inner ear and can be recorded within the ear canal. Since OAEs can reflect the functional status of the inner ear, OAE measurements have been widely used for hearing loss screening in the clinic. However, there are limitations in current clinical OAE measurements, such as the restricted frequency range, low efficiency and inaccurate calibration. In this dissertation project, a new method of OAE measurement which used a swept tone to evoke the stimulus frequency OAEs (SFOAEs) was developed to overcome the limitations of current methods. In addition, an in-situ calibration was applied to equalize the spectral level of the swept-tone stimulus at the tympanic membrane (TM). With this method, SFOAEs could be recorded with high resolution over a wide frequency range within one or two minutes. Two experiments were conducted to verify the accuracy of the in-situ calibration and to test the performance of the swept-tone SFOAEs. In experiment I, the calibration of the TM sound pressure was verified in both acoustic cavities and real ears by using a second probe microphone. In addition, the benefits of the in-situ calibration were investigated by measuring OAEs under different calibration conditions. Results showed that the TM pressure could be predicted correctly, and the in-situ calibration provided the most reliable results in OAE measurements. In experiment II, a three-interval paradigm with a tracking-filter technique was used to record the swept-tone SFOAEs in 20 normal-hearing subjects. The test-retest reliability of the swept-tone SFOAEs was examined using a repeated-measure design under various stimulus levels and durations. The accuracy of the swept-tone method was evaluated by comparisons with a standard method using discrete pure tones. Results showed that SFOAEs could be reliably and accurately measured with the swept-tone method. Comparing with the pure-tone approach, the swept-tone method showed significantly improved efficiency. The swept-tone SFOAEs with in-situ calibration may be an alternative of current clinical OAE measurements for more detailed evaluation of inner ear function and accurate diagnosis.
ContributorsChen, Shixiong (Author) / Bian, Lin (Thesis advisor) / Yost, William (Committee member) / Azuma, Tamiko (Committee member) / Dorman, Michael (Committee member) / Arizona State University (Publisher)
Created2012
Description
Older adults often experience communication difficulties, including poorer comprehension of auditory speech when it contains complex sentence structures or occurs in noisy environments. Previous work has linked cognitive abilities and the engagement of domain-general cognitive resources, such as the cingulo-opercular and frontoparietal brain networks, in response to challenging speech. However, the degree to which these networks can support comprehension remains unclear. Furthermore, how hearing loss may be related to the cognitive resources recruited during challenging speech comprehension is unknown. This dissertation investigated how hearing, cognitive performance, and functional brain networks contribute to challenging auditory speech comprehension in older adults. Experiment 1 characterized how age and hearing loss modulate resting-state functional connectivity between Heschl’s gyrus and several sensory and cognitive brain networks. The results indicate that older adults exhibit decreased functional connectivity between Heschl’s gyrus and sensory and attention networks compared to younger adults. Within older adults, greater hearing loss was associated with increased functional connectivity between right Heschl’s gyrus and the cingulo-opercular and language networks. Experiments 2 and 3 investigated how hearing, working memory, attentional control, and fMRI measures predict comprehension of complex sentence structures and speech in noisy environments. Experiment 2 utilized resting-state functional magnetic resonance imaging (fMRI) and behavioral measures of working memory and attentional control. Experiment 3 used activation-based fMRI to examine the brain regions recruited in response to sentences with both complex structures and in noisy background environments as a function of hearing and cognitive abilities. The results suggest that working memory abilities and the functionality of the frontoparietal and language networks support the comprehension of speech in multi-speaker environments. Conversely, attentional control and the cingulo-opercular network were shown to support comprehension of complex sentence structures. Hearing loss was shown to decrease activation within right Heschl’s gyrus in response to all sentence conditions and increase activation within frontoparietal and cingulo-opercular regions. Hearing loss also was associated with poorer sentence comprehension in energetic, but not informational, masking. Together, these three experiments identify the unique contributions of cognition and brain networks that support challenging auditory speech comprehension in older adults, further probing how hearing loss affects these relationships.
ContributorsFitzhugh, Megan (Author) / (Reddy) Rogalsky, Corianne (Thesis advisor) / Baxter, Leslie C (Thesis advisor) / Azuma, Tamiko (Committee member) / Braden, Blair (Committee member) / Arizona State University (Publisher)
Created2019
Description
With a growing number of adults with autism spectrum disorder (ASD), more and more research has been conducted on majority male cohorts with ASD from young, adolescence, and some older age. Currently, males make up the majority of individuals diagnosed with ASD, however, recent research states that the gender gap is closing due to more advanced screening and a better understanding of how females with ASD present their symptoms. Little research has been published on the neurocognitive differences that exist between older adults with ASD compared to neurotypical (NT) counterparts, and nothing has specifically addressed older women with ASD. This study utilized neuroimaging and neuropsychological tests to examine differences between diagnosis and sex of four distinct groups: older men with ASD, older women with ASD, older NT men, and older NT women. In each group, hippocampal size (via FreeSurfer) was analyzed for differences as well as correlations with neuropsychological tests. Participants (ASD Female, n = 12; NT Female, n = 14; ASD Male, n = 30; NT Male = 22), were similar according to age, IQ, and education. The results of the study indicated that the ASD Group as a whole performed worse on executive functioning tasks (Wisconsin Card Sorting Test, Trails Making Test) and memory-related tasks (Rey Auditory Verbal Learning Test, Weschler Memory Scale: Visual Reproduction) compared to the NT Group. Interactions of sex by diagnosis approached significance only within the WCST non-perseverative errors, with the women with ASD performing worse than NT women, but no group differences between men. Effect sizes between the female groups (ASD female vs. NT female) showed more than double that of the male groups (ASD male vs. NT male) for all WCST and AVLT measures. Participants with ASD had significantly smaller right hippocampal volumes than NT participants. In addition, all older women showed larger hippocampal volumes when corrected for total intracranial volume (TIV) compared to all older men. Overall, NT Females had significant correlations across all neuropsychological tests and their hippocampal volumes whereas no other group had significant correlations. These results suggest a tighter coupling between hippocampal size and cognition in NT Females than NT Males and both sexes with ASD. This study promotes further understanding of the neuropsychological differences between older men and women, both with and without ASD. Further research is needed on a larger sample of older women with and without ASD.
ContributorsWebb, Christen Len (Author) / Braden, B. Blair (Thesis advisor) / Azuma, Tamiko (Committee member) / Dixon, Maria (Committee member) / Arizona State University (Publisher)
Created2019
Description
Previous research from Rajsic et al. (2015, 2017) suggests that a visual form of confirmation bias arises during visual search for simple stimuli, under certain conditions, wherein people are biased to seek stimuli matching an initial cue color even when this strategy is not optimal. Furthermore, recent research from our lab suggests that varying the prevalence of cue-colored targets does not attenuate the visual confirmation bias, although people still fail to detect rare targets regardless of whether they match the initial cue (Walenchok et al. under review). The present investigation examines the boundary conditions of the visual confirmation bias under conditions of equal, low, and high cued-target frequency. Across experiments, I found that: (1) People are strongly susceptible to the low-prevalence effect, often failing to detect rare targets regardless of whether they match the cue (Wolfe et al., 2005). (2) However, they are still biased to seek cue-colored stimuli, even when such targets are rare. (3) Regardless of target prevalence, people employ strategies when search is made sufficiently burdensome with distributed items and large search sets. These results further support previous findings that the low-prevalence effect arises from a failure to perceive rare items (Hout et al., 2015), while visual confirmation bias is a bias of attentional guidance (Rajsic et al., 2015, 2017).
ContributorsWalenchok, Stephen Charles (Author) / Goldinger, Stephen D (Thesis advisor) / Azuma, Tamiko (Committee member) / Homa, Donald (Committee member) / Hout, Michael C (Committee member) / McClure, Samuel M. (Committee member) / Arizona State University (Publisher)
Created2018
Description
Cognitive deficits often accompany language impairments post-stroke. Past research has focused on working memory in aphasia, but attention is largely underexplored. Therefore, this dissertation will first quantify attention deficits post-stroke before investigating whether preserved cognitive abilities, including attention, can improve auditory sentence comprehension post-stroke. In Experiment 1a, three components of attention (alerting, orienting, executive control) were measured in persons with aphasia and matched-controls using visual and auditory versions of the well-studied Attention Network Test. Experiment 1b then explored the neural resources supporting each component of attention in the visual and auditory modalities in chronic stroke participants. The results from Experiment 1a indicate that alerting, orienting, and executive control are uniquely affected by presentation modality. The lesion-symptom mapping results from Experiment 1b associated the left angular gyrus with visual executive control, the left supramarginal gyrus with auditory alerting, and Broca’s area (pars opercularis) with auditory orienting attention post-stroke. Overall, these findings indicate that perceptual modality may impact the lateralization of some aspects of attention, thus auditory attention may be more susceptible to impairment after a left hemisphere stroke.
Prosody, rhythm and pitch changes associated with spoken language may improve spoken language comprehension in persons with aphasia by recruiting intact cognitive abilities (e.g., attention and working memory) and their associated non-lesioned brain regions post-stroke. Therefore, Experiment 2 explored the relationship between cognition, two unique prosody manipulations, lesion location, and auditory sentence comprehension in persons with chronic stroke and matched-controls. The combined results from Experiment 2a and 2b indicate that stroke participants with better auditory orienting attention and a specific left fronto-parietal network intact had greater comprehension of sentences spoken with sentence prosody. For list prosody, participants with deficits in auditory executive control and/or short-term memory and the left angular gyrus and globus pallidus relatively intact, demonstrated better comprehension of sentences spoken with list prosody. Overall, the results from Experiment 2 indicate that following a left hemisphere stroke, individuals need good auditory attention and an intact left fronto-parietal network to benefit from typical sentence prosody, yet when cognitive deficits are present and this fronto-parietal network is damaged, list prosody may be more beneficial.
Prosody, rhythm and pitch changes associated with spoken language may improve spoken language comprehension in persons with aphasia by recruiting intact cognitive abilities (e.g., attention and working memory) and their associated non-lesioned brain regions post-stroke. Therefore, Experiment 2 explored the relationship between cognition, two unique prosody manipulations, lesion location, and auditory sentence comprehension in persons with chronic stroke and matched-controls. The combined results from Experiment 2a and 2b indicate that stroke participants with better auditory orienting attention and a specific left fronto-parietal network intact had greater comprehension of sentences spoken with sentence prosody. For list prosody, participants with deficits in auditory executive control and/or short-term memory and the left angular gyrus and globus pallidus relatively intact, demonstrated better comprehension of sentences spoken with list prosody. Overall, the results from Experiment 2 indicate that following a left hemisphere stroke, individuals need good auditory attention and an intact left fronto-parietal network to benefit from typical sentence prosody, yet when cognitive deficits are present and this fronto-parietal network is damaged, list prosody may be more beneficial.
ContributorsLaCroix, Arianna (Author) / Rogalsky, Corianne (Thesis advisor) / Azuma, Tamiko (Committee member) / Braden, B. Blair (Committee member) / Liss, Julie (Committee member) / Arizona State University (Publisher)
Created2019
Description
The purpose of the present study was to determine if vocabulary knowledge is related to degree of hearing loss. A 50-question multiple-choice vocabulary test comprised of old and new words was administered to 43 adults with hearing loss (19 to 92 years old) and 51 adults with normal hearing (20 to 40 years old). Degree of hearing loss ranged from mild to moderately-severe as determined by bilateral pure-tone thresholds. Education levels ranged from some high school to graduate degrees. It was predicted that knowledge of new words would decrease with increasing hearing loss, whereas knowledge of old words would be unaffected. The Test of Contemporary Vocabulary (TCV) was developed for this study and contained words with old and new definitions. The vocabulary scores were subjected to repeated-measures ANOVA with definition type (old and new) as the within-subjects factor. Hearing level and education were between-subjects factors, while age was entered as a covariate. The results revealed no main effect of age or education level, while a significant main effect of hearing level was observed. Specifically, performance for new words decreased significantly as degree of hearing loss increased. A similar effect was not observed for old words. These results indicate that knowledge of new definitions is inversely related to degree of hearing loss.
ContributorsMarzan, Nicole Ann (Author) / Pittman, Andrea (Thesis director) / Azuma, Tamiko (Committee member) / Wexler, Kathryn (Committee member) / Department of Speech and Hearing Science (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Spousal loss is a common, significant life event that can negatively affect multiple facets of individual health and psychological adjustment. Social support is one factor that is shown to improve adjustment following spousal loss, but much less is known regarding which facet of social support is most predictive of positive adjustment outcomes following spousal loss. This study examined the course of changes in mental health and well-being following spousal loss and which facets of social support are associated with better outcomes following spousal loss. Latent growth curve modeling was applied to data from 265 widowed individuals, ages 65 and older, across four assessments (baseline, and 6-, 18-, and 48- months following spousal loss). I examined the following research questions: (1) adjustment following spousal loss will follow a trajectory of an increase in depressive symptoms and anxiety and decrease in well-being with a leveling-off over time, with between-person differences, and (2) emotional support and instrumental support given will lead to more positive adjustment outcomes over time. Depressive symptoms followed the hypothesized trajectory but anxiety and well-being showed relative stability before and after spousal loss. Instrumental support was the most beneficial facet of social support, such that receiving more instrumental support was associated with lower levels of depressive symptoms and anxiety 6-months following spousal loss. Giving more instrumental support led to an increase in well-being following spousal loss. Instrumental support given and received led to increases in well-being as a function of spousal loss. The discussion focuses on whether and how these findings can help to identify ways through which support and help can be given to individuals to improve adjustment to spousal loss and fully recover.
ContributorsSullivan, Colleen Elizabeth (Author) / Infurna, Frank (Thesis director) / Luthar, Suniya (Committee member) / Davis, Mary (Committee member) / Department of Psychology (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12