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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.
21

An Examination of the Effects of Mode of Access on the Computerized Revised Token Test

Heilman, Laura E. 08 September 2008 (has links)
Background: The Computerized Revised Token Test (CRTT) was recently developed to improve the reliability and accessibility of the Revised Token Test (RTT). The CRTT was standardized using a touchscreen monitor; however, for various reasons, clinicians may need to use a mouse for test administration. In general, research suggests that younger individuals who are familiar with computers are more accurate and prefer to use a mouse. However, this may not be the case for brain-damaged persons with physical limitations. Thus, comparable performance when different input devices are used cannot be assumed. Aims: The purpose was to investigate similarities and differences between participants performance on subtest and overall scores obtained from touchscreen versus mouse on the CRTT. The study also examined the test-retest reliability of the CRTT when different input devices were used and user preference. Methods & Procedures: Forty young, healthy adults participated in this study. All participants were native English speakers, and had no history of a speech, language, or learning disability. Participants passed a language screening, the Story Retell Procedure (SRP) (McNeil, Doyle, Park, Fossett, & Brodsky, 2002). Each participant took the CRTT with both modes of access, a mouse and a touchscreen, with their non-dominant hand. One-half (20) of the participants were administered both versions of the CRTT a second time. Additionally, all participants answered a preference questionnaire. Outcomes & Results: The results revealed that touchscreen overall scores were significantly higher than mouse scores. There were also significant differences on six of the ten subtests. The test-retest reliability for both versions was equivalent and not significantly different. The results indicated a significant preference for the touchscreen. Conclusions: While the touchscreen access method produced significantly higher subtest and overall CRTT scores than the mouse access method, along with equivalent reliability performance in this young normal participant population, it is not clear that it should be used as the preferred access method. If successful algorithms for equating the previously established psychometric data and normative sample derived from the touchscreen access method can be generated, then there will be no need to re-standardize the test.
22

COMPARISON OF SPEECH AND PRACTICED NONSPEECH INTRAORAL PRESSURE WAVEFORM CHARACTERISTICS

Klusek, Jessica 08 September 2008 (has links)
Intraoral pressure waveforms of a learned volitional nonspeech task were compared to that of a parallel speech task in order to drawl inferences regarding a possible shared sensorimotor control mechanism. Similarities between the dependent variables at question (the percents of the increase and decrease interval involved in the total duration and the slopes of the increase and decrease interval) may provide preliminary evidence of a shared generalized motor program. The nonspeech task (which was devised as part of a larger study by Shaiman et al., 2004; 2006) reflected the goal and complexity of speech, by the incorporation of intraoral pressure targets and practiced, co-articulated gestures. Six subjects participated in the study. Subjects practiced the nonspeech task over two sessions, totaling to over 600 repetitions of the task, with KR regarding accuracy of reaching the pressure target provided for 65% of trials. Nonspeech retention data was gathered at the end of both practicing sessions. Parallel speech task data were then taken. The measures of the dependent variables were calculated by the division of the pressure waveform into three distinct intervals: the increase, plateau, and decrease interval. These intervals were automatically detected using a pressure waveform analysis program, which used the first derivative of the pressure signal to mark parts of the waveform. The means for the nonspeech retention data and the speech data were taken for each dependent variable. Univariate analysis revealed no significant difference between the speech and nonspeech condition for any of the four dependent variables (p<0.05). The finding of no significant difference for any of the four dependent variables may provide preliminary evidence for a shared generalized motor program for speech and nonspeech gestures. However, future research with data from additional subjects would assess this finding. Also, descriptive observations of waveform shape during the plateau interval indicate the need for further analysis of additional waveform measurements not analyzed in the current study, and also the need to control rate and precision of production in the future.
23

Examining inter-sentential influences on predicted verb subcategorization

Brady, Jill Louise 22 January 2009 (has links)
This study investigated the influences of prior discourse context and cumulative syntactic priming on readers predictions for verb subcategorizations. An additional aim was to determine whether cumulative syntactic priming has the same degree of influence following coherent discourse contexts as when following series of unrelated sentences. Participants (N = 40) read sentences using a self-paced, sentence-by-sentence procedure. Half of these sentences comprised a coherent discourse context intended to increase the expectation for a sentential complement (S) completion. The other half consisted of scrambled sentences. The trials in both conditions varied according to the proportion of verbs that resolved to an S (either 6S or 2S). Following each condition, participants read temporarily ambiguous sentences that resolved to an S. Reading times across the disambiguating and postdisambiguating regions were measured. No significant main effects or interactions were found for either region. However, the lack of significant findings for these analyses may have been due to low power. In a follow-up analysis, data from each gender were analyzed separately. For the data contributed by males, there were no significant findings. For the data contributed by females, the effect of coherence was significant (by participants but not by items) across the postdisambiguating region, and there was a marginally significant interaction (p =.05) between coherence and frequency across this region suggesting that discourse-level information may differentially influence the local sentence processing of female and male participant.
24

Instant Messenger Use by Individuals with Asperger's Syndrome

Coburn, Kelly L. 29 April 2009 (has links)
Aspergers Syndrome is an autism spectrum disorder in which patients generally exhibit average or above-average intelligence and linguistic ability, but considerable difficulty building social relationships. Its incidence has increased greatly since the 1990s. Also since the 1990s, personal computers have come into wide use as tools not only for work, but also for social communication (Baron, 1998). Computer-mediated communication (CMC) technologies, such as instant messaging (IM), have become very popular with the general public in this time frame. In order to determine whether IM will be a useful social tool for people with Aspergers, in this study, a corpus of IM conversations from volunteers both with and without Aspergers, conversing with their peers was collected and analyzed to identify patterns of use of standard English lexemes and characteristic IM lexemes. A lexeme is a minimal unit of semantic meaning, which usually corresponds roughly to a word. Emoticons (such as the smiley :-)), acronyms (such as lol), characteristic abbreviations (like probly for probably), and typed representations of non-uttered events (like *hugs you* or I hug you) are examples of characteristic IM lexemes. It was hypothesized that people with Aspergers would use significantly more standard English lexemes, and fewer lexemes that are unique to IM, per sent message than would be used by their neurotypical peers. Additionally, it was hypothesized that people with Aspergers would use fewer sent messages to complete an apparent thought than their neurotypical peers. Participants were recruited in already-acquainted pairs through a peer mentoring program for college students with autism and developmental disabilities. Conversational partners were matched based on their acquaintance with each other. Each Aspergers and neurotypical participant held one or two fifteen- to twenty-minute conversations using AOL Instant Messenger®. The conversations were recorded, transcribed and analyzed to compare the use of characteristic IM lexemes and structural aspects of each conversation. The lexemes were counted to determine their frequency in each whole conversation. The number of sent messages in each conversation, the number of sent messages per conversational turn, and the number of lexemes (both IM and standard English) per sent message were counted and compared. Results showed no significant differences between groups on any of the variables, or for the behavior of the control group between conditions, suggesting that people with Aspergers are likely to communicate in this medium in ways that are very similar to their neurotypical peers. Implications of this pilot data and potential directions for future research are discussed.
25

Age and Phonetic Context Effects in Children vs. Adults

Utz, Tessa 30 April 2009 (has links)
In normal hearing adults, acoustic context influences perception of speech in a spectrally contrastive manner. The aim of this study is to investigate whether typically developing children, aged 5 through 6 and 7 through 9 years, demonstrate phonetic context effects in a manner and extent similar to adults. By comparing the childrens responses to those of adults aged 18 to 28 years, it will be determined if the childrens use of phonetic context is limited by maturity. A total of 61 individuals participated in this study: 45 adults and 16 children. The participants listened to isolated vowels along the /ʌ/ to /ɛ/ acoustic continuum and indicated if they heard /ʌ/ or /ɛ/. They then listened to the same vowel continuum within a /d/-Vowel-/d/ syllable context and in a /b/-Vowel-/b/ syllable context. With each syllable presentation the participants identified the vowel sound that they heard. The participants responses were assessed for shifts in the vowel perceptual boundaries relative to consonant context. The results indicated that the older children and the adults exhibited a context effect, but as a group, the younger children did not exhibit the effect. However, some of the younger children presented an effect that was consistent with the Older Children and Adults.
26

Story Comprehension by Adults with Right Hemisphere Brain Damage

Intintoli, Jessica L 30 April 2009 (has links)
Background: Right hemisphere brain damage (RHD) manifests itself in many ways. The repercussions affecting language function are distinct; studies in discourse comprehension in RHD groups suggest that this population struggles with the mental structures necessary for processing, leading to difficulty when a task requires that participants modify their established mental models or alter first interpretations. The current investigation was based on an experiment in Rapp et al.s (2001) study that suggests that trait-based models of discourse processing affect online reading. Participants response times slowed when the final sentences of the story stimuli were inconsistent with character traits instantiated in the beginning of the stories. Aims: The current study examined the nature of discourse comprehension difficulties in adults with right hemisphere brain damage, specifically observing how participants with RHD performed in accuracy and response times when presented stories with inconsistencies in character trait portrayal. Methods and Procedures: Participants included eight adults with RHD and five with no brain damage (NBD). Participants listened to 20 stimuli featuring either a neutral or trait-instantiating first portion (describing a specific trait of a character), followed by a trait-consistent or trait-inconsistent final sentence. Asked to make a rapid judgment concerning whether the final sentence of each story fit with the personality of the character featured in that story, the subjects chose yes or no on a manual response box. Ancillary tasks were used to assist in classifying the clinical characteristics of participants and to provide potential alternative interpretations of participants performances. Outcomes and Results: The results of this study suggest that when character traits are strongly negative and/or strongly implied, adults with RHD appear to incorporate these character biases in their narrative processing, though these biases do not improve their judgments of trait-inconsistent information. As predicted, there were no group differences in trait-instantiating stories with the trait-consistent endings, but the participants with RHD were less accurate in the trait-inconsistent condition than the group with NBD. Supporting the studys main hypothesis, results indicate that adults with RHD are as able as control participants to accurately judge trait-consistent information, but are at a disadvantage when dealing with incongruity.
27

Investigating Comprehension Differences Between Active and Passive Sentences in a Young and Older Adult Population

Yang, Dorothy 22 May 2009 (has links)
The current investigation sought to determine whether normal, non-impaired young and older adults performed differentially on the active and passive sentences of the Computerized Revised Token Test Active/Passive (CRTT-A/P). Twenty-five young adults (18 to 30 years old) and twenty-five older adults (50 to 80 years old) completed this study. The first purpose of this study was to determine if the two groups (i.e., young and older) differed significantly in their performance (as measured by overall mean scores) on the two sentence types (i.e., active and passive sentences) across each of the four subtests. Significant differences between subtests were found; participants obtained significantly higher scores on Subtest VIII than on Subtest V and Subtest VI. The second purpose of this study was to determine if the two groups differed significantly in their efficiency scores on the two sentence types across each of the four subtests. It was found that (1) participants obtained significantly higher efficiency scores on Subtest VII than on Subtests V and VI and that (2) participants obtained significantly higher efficiency scores on Subtest VIII than on Subtest VI. The final purpose of this study was to determine if the two groups differed significantly in their response times on the two sentence types across each of the four subtests. It was found that: (1) participants responded more quickly to the passive sentence type than to the active sentence type across all four subtests; (2) the older group responded more quickly on Subtest V than on Subtests VI and VIII; and (3) the older group responded more quickly on Subtest VII than on Subtests VI and VIII. When differences between the two groups were examined for all of the measures, only one significant difference was found (the older group performed significantly slower than the young group on Subtests VI and VIII). These findings demonstrate that language comprehension abilities remain relatively constant with age. While the CRTT-A/P did not detect any significant comprehension differences between active and passive sentences in young and older individuals, this test has yet to be administered to various pathological groups (e.g., persons with agrammatic comprehension). This study thus provides preliminary data for future comparisons with pathological populations. Such studies are equally important for advancing our understanding of the way we comprehend language and form grammatical meaning.
28

Biosimulation of Vocal Fold Inflammation and Healing

Li, Nicole Yee-Key 05 June 2009 (has links)
Personalized, pre-emptive and predictive medicine is the capstone of contemporary medical care. The central aim of this dissertation is to address clinical challenges in prescribing personalized therapy to patients with acute phonotrauma. Inflammation and healing, which are innate tissue responses to mechanical stress/ trauma, are regulated by a complex dynamic system. A systems biology approach, which combines empirical, mathematical and computational tools, was taken to study the biological complexity of this dynamic system in vocal fold injury. Computational agent-based models (ABMs) were developed to quantitatively characterize multiple cellular and molecular interactions around inflammation and healing. The models allowed for tests of various hypothetical effects of motion-based treatments in individuals with acute phonotrauma. A phonotrauma ABM was calibrated and verified with empirical data of a panel of inflammatory mediators, obtained from laryngeal secretions in individuals following experimentally induced phonotrauma and a randomly assigned motion-based treatment. A supplementary ABM of surgically induced vocal fold trauma was developed and subsequently calibrated and verified with empirical data of inflammatory mediators and extracellular matrix substances from rat studies, for the purpose of gaining insight into the &ldquo net effect &rdquo of cellular and molecular responses at the tissue level. ABM simulations reproduced and predicted trajectories of inflammatory mediators and extracellular matrix as seen in empirical data of phonotrauma and surgical vocal fold trauma. The simulation results illustrated a spectrum of inflammatory responses to phonotrauma, surgical trauma and motion-based treatments. The results suggested that resonant voice exercise may optimize the combination of para- and anti-inflammatory responses to accelerate healing. Moreover, the ABMs suggested that hyaluronan fragments might be an early molecular index of tissue damage that is sensitive to varying stress levels from relatively low phonatory stress to high surgical stress. We propose that this translational application of biosimulation can be used to quantitatively chart individual healing trajectories, test the effects of different treatment options and most importantly provide new understanding of laryngeal health and healing. By placing biology on a firm mathematical foundation, this line of research has potential to influence the contour of scientific thinking and clinical care of vocal fold injury.
29

The effects of stress reactivity on extralaryngeal muscle tension in vocally normal participants as a function of personality

Dietrich, Maria 05 June 2009 (has links)
The theory of the dispositional bases of vocal nodules and functional dysphonia (Roy & Bless, 2000) represents an important step toward the understanding of the relation between personality and voice disorders. However, experimental tests of this theory are widely lacking. In this study, female healthy and vocally normal adults between the ages of 18-35 years were divided into two groups, introversion (n = 27) and extraversion (n = 27), based on results on the Eysenck Personality Questionnaire- Revised (EPQ-R). Both groups underwent a stress reactivity protocol, which involved a simulated public speaking stressor in addition to baseline speech, rest, and recovery phases. Participants in the introversion group had significantly higher scores on voice handicap and depression than participants in the extraversion group. The introversion group exhibited significantly greater infrahyoid muscle activity (surface electromyography) and perceptions of vocal effort throughout the protocol. However, although greater stress reactivity was also descriptively observed for those measures in the introversion group, the phase by personality interaction was non-significant as were group differences for submental and anterior tibialis muscle activity. Voice fundamental frequency and intensity significantly decreased during stressor exposure for both groups. The stress induction was effective and significantly increased systolic blood pressure (SBP) and negative affect in everyone. The degree of rumination was not different between groups, but the participants with introversion experienced significantly more fear of public speaking. Neither SBP, negative affect, nor fear of public speaking were significantly correlated with SEMG activity in the participant pool. Instead the trait introversion was significantly and positively correlated with infrahyoid muscle activity in the total sample. This psychobiological study is first examination of the trait theory of voice disorders to focus on the role of stress reactivity. Results indicated that persons with introversion had a disposition towards increased infrahyoid extralaryngeal muscle activity combined with greater perceptions of vocal effort during speech, which were both magnified under conditions of psychological stress. Findings were tentatively interpreted to be consistent with behavioral inhibition in individuals high on introversion as predicted in the trait theory of voice disorders, which may constitute a risk factor for muscle tension dysphonia.
30

THE EFFECTS OF LOCALITY ON SENTENCE COMPREHENSION IN PERSONS WITH APHASIA AND NORMAL INDIVIDUALS

Sung, Jee Eun 11 January 2010 (has links)
The first aim of the current study was to investigate the effects of the distance manipulation on sentence comprehension in normal individuals (NI) and persons with aphasia (PWA). Consistent with Gibson¡¯s (1998; 2000) locality theory, when distance was manipulated by varying the syntactic dependency (subject-verb: SV and filler-gap: FG) and type of modifier (No, prepositional-phrase: PP, and relative-clause: RC), NI demonstrated an increase in the number of errors and response times to the yes/no questions as the distance increases. NI also exhibited a relatively systematic increase of reading times on the verb (RT-V) and response times (RT) as a function of distance manipulation except for the most complex condition (FG-RC) in which 77% of NI performed at chance-level. More than 60% of normal individuals performed at chance-level in sentences with FG-dependency. Consistent with the previous literature on syntactic comprehension in aging, older adults showed decreased performance on the filler-gap computations. PWA generated more errors in the FG- than SV-dependency. However, their sentence comprehension was not affected by the manipulation of the modifiers. Their RT-V data were difficult to interpret due to the very limited observations for FG-dependency conditions after chance-level performers were excluded from the analyses. One can argue that the high rate of chance-level performance in PWA, especially in the FG conditions, is consistent with the specific impairments hypotheses. However, chance-level performance was observed in majority of individuals with aphasia and even in normal individuals, which was not predicted by those hypotheses. The current results were more consistent with resource-related hypotheses which suggested that sentence comprehension deficits will manifest themselves regardless of the type of aphasia when their capacity is taxed to be exceeded. When distance-based integration cost was held constant between the two dependencies, FG-dependency generated more errors across the groups. However, the RT-V was not significantly different between the two conditions in older adults. These results are consistent with the locality theory. Considering the longer RT-V differences between FG- and SV-dependency in older adults than younger adults, the non-significant group results might be due to the large variability of older adults¡¯ performance and the limited sample size.

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