Hearing & Speech Sciences Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/2776
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Item Auditory Temporal Processing Ability in Cochlear-Implant Users: The Effects of Age and Peripheral Neural Survival(2019) Shader, Maureen Joyce; Goupell, Matthew J; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Cochlear implants (CIs) are a valuable tool in the treatment of hearing loss and are considered a safe and effective option for adults of all ages. Nevertheless, older adults with CIs do not always achieve comparable speech recognition performance to younger adults following implantation. The mechanism(s) underlying this age limitation are unknown. It was hypothesized that older CI users would demonstrate age-related deficits in auditory temporal processing ability, which could contribute to an age limitation in CI performance. This is because the ability to accurately encode temporal information is critical to speech recognition through a CI. The current studies were aimed at identifying age-related limitations for processing temporal information using a variety of electrical stimulation parameters with the goal of identifying parameters that could mitigate the negative effects of age on CI performance. Studies 1 and 2 measured auditory temporal processing ability for non-speech signals at the single-electrode level for various electrical stimulation rates. Specifically, Study 1 measured gap detection thresholds, which constitutes a simple, static measurement of temporal processing. Study 2 measured amplitude-modulation detection thresholds, which utilized relatively more complex and dynamic signals. Peripheral neural survival was estimated on each electrode location that was tested in Studies 1 and 2. Study 3 measured phoneme recognition ability for consonant contrasts that varied in discrete temporal cues at multiple stimulation rates and envelope modulation frequencies. Results demonstrated significant effects of age and/or peripheral neural survival on temporal processing ability in each study. However, age and the degree of neural survival were often strongly correlated, with older participants exhibiting poorer neural survival compared to younger participants. This result suggested that a substantial reduction in peripheral neural survival accompanies aging in older CI users, and that these factors should be considered together, rather than separately. Parametric variation in the stimulation settings impacted performance for some participants, but this effect was not consistent across participants, nor was it predicted by age or peripheral neural survival.Item Intelligibility in Children with Cochlear Implants: The /t/ vs. /k/ Contrast(2019) Leonard, Elinora C; Edwards, Jan; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Previous research has found that the speech of children with cochlear implants (CI) is less intelligible than the speech of peers with normal hearing (NH). This claim has been supported by research showing that children with CIs have difficulty with the late-acquired spectral contrast of /s/ vs. /ʃ/: correctly produced words containing these initial-consonants are less intelligible when produced by children with CIs relative to children with NH. The current study examined whether a similar result is observed with the early-acquired spectral contrast of /t/ vs. /k/. Crowd-sourced data were used to evaluate intelligibility of /t/- and /k/-initial words correctly produced by children with CIs and children with NH embedded in multi-talker babble. Results indicated that whole-word productions of children with CIs were less intelligible than productions of children with NH for words beginning with this early-acquired contrast. However, results also indicated this difference in intelligibility was not dependent on the intelligibility of the initial consonant alone.Item AN INVESTIGATION OF NEURAL MECHANISMS UNDERLYING VERB MORPHOLOGY DEFICITS IN APHASIA(2019) Pifer, Madeline R; Faroqi-Shah, Yasmeen; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Agrammatic aphasia is an acquired language disorder characterized by slow, non-fluent speech that include primarily content words. It is well-documented that people with agrammatism (PWA) have difficulty with production of verbs and verb morphology, but it is unknown whether these deficits occur at the single word-level, or are the result of a sentence-level impairment. The first aim of this paper is to determine the linguistic level that verb morphology impairments exist at by using magnetoencephalography (MEG) scanning to analyze neural response to two language tasks (one word-level, and one sentence-level). It has also been demonstrated that PWA benefit from a morphosemantic intervention for verb morphology deficits, but it is unknown if this therapy induces neuroplastic changes in the brain. The second aim of this paper is to determine whether or not neuroplastic changes occur after treatment, and explore the neural mechanisms by which this improvement occurs.Item Role of Processing Speed and Cognitive Control during Word Retrieval in Persons with Aphasia(2019) Gehman, Megan; Faroqi-Shah, Yasmeen; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)It is possible that word retrieval is not associated with general processing speed but is associated with a highly specific cognitive process - that of inhibiting competing alternative words. This study aims to measure domain general processing speed, domain general cognitive control, domain specific linguistic processing, and domain specific linguistic selection control. Twelve PWA and 15 neurotypical controls completed all four tasks. Results: domain general processing speed and domain general cognitive control response times differed between the groups but were nonsignificant. In neurotypical adults, word retrieval response time was predicted by domain general measures. However, this pattern was not observed in PWA – rather, word retrieval was predicted by domain specific linguistic measures. The implications of these findings indicate that aphasia is ultimately defined by language deficits, and increased word retrieval times in PWA cannot be attributed to a generalized processing speed deficit.Item INVESTIGATING THE EFFECT OF PARENTAL QUESTION INPUT ON CHILDREN WITH ASD(2019) Curdts, Lydia Leslie; Bernstein-Ratner, Nan; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The current study analyzed individual mechanisms of language gains following the Solomon et al. (2014) randomized control trial (RCT) of the Play and Language for Autistic Youngsters (PLAY) Project, a DIR/Floortime based early intervention program for children with autism spectrum disorder. 80 parent-child play interactions from the original RCT were analyzed to assess the relationship between various forms of parental question input, as taught in PLAY parent trainings, and child language measures. While high parental question input did correlate with high child language measures, one targeted intervention component, parental Asked/Answered question input, did not increase following parent training and did not improve child language measures. We consider other mechanisms responsible for successful child language gains following PLAY intervention.Item The effect of child gender on parental nonverbal communication(2019) Booth, Tiara; Newman, Rochelle; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Previous work has studied parental verbal communication and found differences based on child gender. The current study was designed to better understand any differences in maternal nonverbal communication based on child gender. The nonverbal parameters analyzed were eye contact/joint attention, gestures, positive and negative facial expressions, and open and closed body language. Previously recorded mother-child play sessions when the children were 7 months (n=103) and 24 months (n=73) were coded to assess three main questions: a) Does maternal nonverbal communication differ with child gender? b) Does maternal nonverbal communication change over time? c) Does maternal nonverbal communication effect vocabulary outcomes at 24 months? Mothers used more positive facial expressions with girls at 7 months and more gestures with boys at 24 months. Mothers were consistent in their use of positive facial expressions and gestures over time. Finally, there was no apparent relationship between maternal nonverbal communication and vocabulary.Item Understanding and remembering pragmatic inferences(2018) Kowalski, Alix; Huang, Yi Ting; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This dissertation examines the extent to which sentence interpretations are incrementally encoded in memory. While traditional models of sentence processing assume that comprehension results in a single interpretation, evidence from syntactic parsing indicates that initial misinterpretations are sometimes maintained in memory along with their revised counterparts (e.g., Christianson, Hollingworth, Halliwell & Ferreira, 2001). However, this evidence has largely come from experiments featuring sentences that are presented in isolation and words that are biased toward incorrect syntactic analyses. Because there is typically enough sentential context in natural speech to avoid the incorrect analysis (Roland, Elman, & Ferreira, 2006), it is unclear whether initial interpretations are incrementally encoded in memory when there is sufficient context. The scalar term “some” provides a test case where context is necessary to select between two interpretations, one based on semantics (some and possibly all) and one based on pragmatic inference (some but not all) (Horn, 1989). Although listeners strongly prefer the pragmatic interpretation (e.g., Van Tiel, Van Miltenburg, Zevakhina, & Geurts, 2016), prior research suggests that the semantic meaning is considered before the inference is adopted (Rips, 1975; Noveck & Posada, 2003; Bott & Noveck, 2004; Breheny, Katsos, & Williams, 2006; De Neys & Schaeken, 2007; Huang & Snedeker, 2009, 2011). I used a word-learning and recall task to show that there is evidence of the semantic meaning in the memory representation of sentences featuring “some,” even when the pragmatic interpretation is ultimately adopted. This raises two possibilities: first, the memory representation was of poor quality because both interpretations were available during encoding, or the semantic meaning was computed and encoded first and lingered even after the pragmatic interpretation was computed and encoded. Data from a conflict-adaptation experiment revealed a facilitating effect of cognitive control engagement. However, there was still a delay before the pragmatic inference was adopted. This suggests that only the semantic meaning is available initially and the system failed to override it in memory when the pragmatic interpretation was computed. Taken together, these findings demonstrate the incrementality of memory encoding during sentence processing.Item Linguistic Influences on Disfluencies in Typically-Developing French-English Bilingual Children(2018) Azem, Andrea Sabrije; Ratner, Nan; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The connections among language proficiency, language complexity, and fluency have been well-researched in both typical and atypical monolingual populations. Though previous work indicates that bilingual individuals often demonstrate different patterns of disfluency in each of their languages, how or why this happens is largely unknown. Relationships among fluency, language proficiency, and language complexity were examined using the narrative and conversational speech samples of 9 French-English bilingual children. Mean length of utterance in words (MLUw) and percent grammatical utterances (PGU) were shown to strongly relate to rates of total disfluency. The proportion of disfluent function words across samples differed significantly from the proportion of disfluent content words, although rates of disfluency on individual parts of speech did not differ significantly between French and English. Further work is necessary in order to better understand the extent to which language proficiency and linguistic complexity interact and affect disfluency across bilingual populations.Item THE ROLE OF PERSONALITY AND COGNITIVE-LINGUISTIC DEFICITS IN TEENS AND ADULTS WITH CONCUSSION(2018) Stockbridge, Melissa Dawn; Newman, Rochelle S; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Even the mildest form of traumatic brain injury, concussion, can result in adverse physical, cognitive, behavioral, and social consequences. Concussion injuries frequently result in patients who describe deficits in daily communication and overall “fogginess,” but whose deficits are not consistently captured on traditional assessments of language. The purpose of this research was two-fold: first, to examine typed written communication in order to better understand the kinds of cognitive and language deficits that adolescents and adults experience immediately and chronically following a concussion; and second, to examine the influence of a particular trait-like dimension of personality and temperament, the propensity toward more frequent, intense, and enduring negative affect (called dispositional negativity), on exacerbation of these deficits. Using a survey conducted entirely online, 92 participants aged 12-40 years old who had a recent concussion, a history of concussion, or no history of brain injury wrote two narrative samples and an expository sample, completed multiple tasks targeting word-level and domain general cognitive skills, and provided rich self-report information important to better understanding their personality, temperament, and mental health. Performance by recently injured participants suggested that deficits in narrative language, though likely influenced by problems in word-finding, memory, and attention, also existed beyond what could be explained by those deficits alone. Narrative-specific deficits were observed in written content, organization, and cohesiveness. Moreover, including dispositional negativity in models of concussion history (group) and self-reported somatic symptomology improved the sensitivity and specificity of these models, which supports the value of considering individual differences in personality when engaged in concussion management.Item INCREMENTAL SENTENCE PRODUCTION IN ADULTS WHO STUTTER: EYE TRACKING WHILE SPEAKING(2018) Frederick, Kerianna; Huang, Yi Ting; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Previous research investigated whether adults who stutter are affected by the same lexical retrieval factors as typically fluent adults. The findings of these studies indicate that the nature of this impact may (Newman & Ratner, 2007) or may not (Hennessey, Nang, & Beilby, 2008) differ between groups. The current study investigates how lexical retrieval unfolds when words are embedded in sentences across these populations. This work used an eye tracking while speaking paradigm during an “A and B are above C” sentence task. Codability and frequency of objects “A” and “B” were manipulated. Adults who stutter and typically fluent adults showed longer gaze duration with increased B difficulty. Total looking times indicated that effects of pre-planning varied with difficulty of A only in typically fluent adults. This suggests that word-level production interacts with sentence-level production. Pre-planning strategies may be less flexible among adults who do stutter than typically fluent adults.