2006 - 2007 Research Colloquium Series
The Communication Sciences and Disorders Department is pleased to announce its Research Colloquium Series. The purpose of the colloquium series is to provide a forum for CSD faculty, doctoral students and invited speakers to present research and to promote discussion. Presentations will range from projects early in the developmental phase to completed projects.
For Fall semester 2006, all presentations are in Dauer Hall room 215 from 11:45am to 12:35pm on the following dates.
Wednesday, January 31
Speaker: Teresa Pitts
Title: Voluntary Cough Production Related to Swallow Dysfunction in PD
Objective: To study voluntary cough production in Parkinson's Disease (PD) patients.
Background: Individuals with PD experience swallow problems. The disabling nature of the swallowing disorder relates to disease stage, although many individuals present with subclinical abnormalities (Pinnington, et al., 2000). Neglect of these symptoms results in poor recovery, difficulty living independently and difficulty performing the activities of daily living (see Kalra et al, 1997). Ability to clear the airway with cough is critical to prevent penetration/aspiration of foreign material during swallow. Measures of impaired cough may be a non-invasive predictor of impairment of bulbar musculature leading to judgements about swallow dysfunction that would dictate videoflourographic assessment. Furthermore, treatments focused on cough/swallow function could use the cough flow waveform to indicate functional change of these two parallel bulbar functions.
Design/Methods: Voluntary cough production from 20 patients with stage II-III PD were examined in relation to their swallow function judged from videoflourographic examination. PD was diagnosed by a certified movement disorders neurologist. Swallow function was defined from the degree of penetration on sequential swallow task of thin 20 cc. bolus. The Penetration/ Aspiration Scale (Rosenbek, et al, 1996) objectively defined the level of penetration. Measures of cough included inspiratory duration, peak inspiratory flow, laryngeal compression time, peak expiratory flow and cough volume acceleration. The 20 patients were retrospectively divided into two groups. Group 1 was defined as any person having penetration into the laryngeal vestibule during sequential swallows as evidenced from the videofluorographic examination. Group 2 was defined as any person with no videoflourographic evidence of penetration during the sequential swallow. Cough flow waveforms for these participants were obtained from a larger study on PD and respiratory strength training.
Results: Results show that there were significant differences between the cough flow waveform parameters between Group 1 and 2.
Conclusions/Relevance: Voluntary cough production can be a useful clinical indicator of aspiration risk.
Wednesday, November 22
Speaker: Maisa Haj-Tas, CSD doctoral student
Title: The effect of syntactic structure on sentence production in adults who stutter.
Abstract: The relationship between linguistic formulation
processes and stuttering has been central to numerous investigations. Although
results of such investigations suggest that stuttering may be related to
difficulties during phonological, semantic, or syntactic processing, most of the
work done to examine this relationship has been with children who stutter. To our
knowledge, only three studies thus far have examined this relationship in speakers
who stutter beyond childhood. In the present study, we examine the effect of the
syntactic structure of the target sentence on speech reaction time and fluency in
adults who do and do not stutter. We do this by using a structural priming
methodology to elicit sentences during a picture description task. Results are
discussed in relation to previous findings on structural priming and on
relationships between syntactic complexity and fluency.
Wednesday, October 25, 2006
Speaker: Peter Park, CSD doctoral student
Title:Literacy development of 7-to 10-year-old children with sensorineural hearing loss: the role of phonological processing and oral language skills in literacy.
Abstract: Over the last two decades, a large body of converging evidence now indicates that dyslexia stems from an underlying deficit in the phonological processing system (Beitchman & Young, 1997; Lyhon, 1995; Mody, 2003; Shaywitz, 1998; Snowling, et al., 1997) or underspecified phonological representations (Snowling et al., 1986; Fowler, 1991; Hansen and Bowey, 1994; Elbro, 1996; Metsala, 1997; Swan and Goswami, 1997a,b). This theoretical consideration led us to a strong consensus that phonological representation capacity plays a crucial and necessary role in the development of oral language and language-based cognitive functions required for normal literacy such as meta-phonological awareness, speech perception, and verbal memory skills. Children with hearing loss are constrained in their access to the ambient speech sounds and language. That is, hearing loss is a condition in which the overall auditory signal of children with hearing loss is quite different from that of children with normal auditory function (Nittrouer, et al., 2005). In this respect, hearing loss, is a naturally occurring alteration/distortion of auditory input, can provide a way of testing the so-called phonological processing hypothesis in literacy development. We hypothesize that phonological processing capacity of the children with hearing loss and the resulting emerging literacy-related cognitive skills would also be negatively affected (Briscoe et al., 2001; Nittrouer et al., 1996; Nitterouer et al., 2005).
While there have been a number of studies of literacy development of children with mild fluctuating hearing loss or profound hearing loss (King & Quigley, 1985; Merrils et al, 1994; Wood et al, 1986), very little is known about the literacy or literacy-related cognitive skills in children with mild-to-severe sensorineural hearing loss (Gibbs, 2004). According to the literature review, only two studies have investigated the comprehensive reading levels of children with mild-to-moderate SNHL as of now (Briscoe et al, 2001; Gibbs, 2004). Furthermore, the results of the previous research are quite opposite to our initial hypothesis (Byrne, 2002; Snowling, 2000; Treiman, 2000). For example, Briscoe et al. (2001) reported that no differences were observed in SNH and age control group on language (vocabulary, sentence comprehension), digit/sentence recall (STM), and literacy. The hearing impaired children's success with reading in spite of depressed phonological processing skills was notable and unexpected. Gibbs (2004) also reported a similar pattern.
This observation raises a critical question regarding the precise role of phonological skills in written language acquisition. That is, according to the "phonological processing hypothesis", impaired phonology would lead to compromised literacy ability since phonological capacity is regarded as a necessary, not a sufficient condition for reading. In addition to this unexpected finding, there are some critical methodological limitations in the previous studies such as unsuccessful control for "hearing loss level" as one of the most important factors for normal phonological development and use of inappropriate selection of testing materials of literacy measurement for hearing impaired children. Moreover, previous research reported reading skills only in limited literacy areas, leaving questions about untested areas unanswered. Thus, reading data on a comprehensive range of literacy and related cognitive areas are not available in the current literature. To sum, further research strictly focusing on the literacy and reading-related cognitive skills in children with mild-to-severe SNHL with appropriate methodology is warranted.
The main purpose of this study is to investigate whether the phonological deficit hypothesis established in the study of developmental reading disorder can be also applied to the literacy development of 7- to 10-year-old children with mild-to-severe sensori-neural hearing loss. Since current studies report some conflicting observations to this principle, this goal is also important from the theoretical point of view. Overcoming several critical methodological limitations is another significant goal of the current study. As noted, our Central Hypothesis is that the contributive and necessary role of phonological processing capacity for literacy found in normal hearing children will also be observed in children with hearing loss. That is, phonological processing capacity and reading performance of 7- to 10-year old children with mild-to-severe SNHL will be shown to be impaired in proportion to the degree of hearing loss level.
The primary purpose of this study is to investigate whether the phonological processing hypothesis in reading development can be applied to the children with hearing loss. Since current studies show equivocal support for the phonological processing principle, the results of this study will be significant theoretical importance.
The secondary purpose of the current study is to examine the strengths and the weaknesses in literacy and literacy-related areas such as phonological awareness and phonological memory in children with differing hearing loss levels. No studies have been conducted to investigate the effect of the differing degree of hearing loss on phonological representation and literacy by successfully in a comprehensive way, while controlling for relevant confounding factors such as the hearing loss level or socioeconomic status.
Finally, by evaluating and comparing the predictive powers of a wider range of reading-related skills, we will be able to provide evidence-based profiles of the phonological capacity of children with hearing loss. This information of the nature of reading development in this population is expected to make a marked contribution to the designing of reading intervention programs for each hard-of-hearing child.
Wednesday, September 27, 2006
Speaker: Sarah Key-DeLyria, CSD doctoral student
Title: The effects of phonetic complexity on vowel formant variability in apraxia of speech
Abstract: Apraxia of speech (AOS) results from left anterior brain damage and is characterized by reduced intelligibility, inconsistent distortion errors and dysprosody. Few studies have systematically investigated speech errors in AOS, possibly due to the high individual variability in production. Analysis of contextual effects may help to describe the sources of variability and elucidate the underlying deficit in apraxia. The purpose of this study was to determine whether consonant complexity affects vowel formants in AOS. Participants repeated 36 consonant-vowel-consonant (CVC) syllables with manipulated consonantal complexity. Each syllable contained one of three vowels: /i/, /a/ or /u/. Acoustic analysis of vowel production by speakers with apraxia revealed formant frequencies within a normal range. Vowel formants in AOS were less stable with greater variability for /u/. Systemic effects of complexity on vowel formant variability in AOS were not observed. The lack of complexity effects suggests that speakers with AOS have disrupted access to syllabic encoding. Further investigation of complexity effects on vowel duration and vowel production variability in consonant-vowel-consonant-vowel (CVCV) contexts is warranted.
Questions regarding the colloquium can be directed to
Dr. Lisa Edmonds at
edmonds@csd.ufl.edu
