▼ The phenomenon of the “missing fundamental frequency” has shown that when the f0 is removed from a complex stimulus the pitch of the f0 is still perceived. This ability for normal hearing adults to process changes in voice pitch has been studied through psychophysical experiments. Through the use of the frequency following response (FFR), relative contributions of the f0 and its harmonics to pitch perception can be examined to determine the role of place cues and temporal cues in pitch processing in the human brainstem. The current study examined the contribution of the f0 and its harmonics in pitch processing by systematically manipulating the speech stimulus to remove component frequencies. It was hypothesized that as the f0 and part of its harmonic components were removed from the stimulus, FFRs would remain stable (in support of the temporal theory), while a response would also be identifiable when only the f0 is preserved (in support of the place theory). FFRs were recorded to seven experimental conditions including the intact, no-f0, harmonics-only and f0-only conditions. A control condition was conducted with the sound tube plugged and moved away from the participants. The results showed distinguishable FFRs in all conditions (except the control condition), with significantly larger FFR Pitch Strength in response to the harmonics-only conditions than those obtained in the f0-only condition (one-way ANOVA, p<0.001). This finding was in support of both the temporal and place theories, with temporal cues contributing more to pitch processing in the human brainstem than place cues. Advisors/Committee Members: Jeng, Fuh-Cherng.

▼ The use of graphic symbols for communicative purposes is a common form of augmentative and alternative communication (AAC) for children with complex communication needs. However, some of the symbols, which represent important early concepts, are difficult for children to recognize. The study implemented a program using video and play activities paired with a direct instruction approach to teach 10 graphic symbols of important early concepts to children with complex communication needs. A single subject multiple baseline across subjects research design was used. Results indicated that program was effective in teaching the target concepts. Advisors/Committee Members: McCarthy, John W.

▼ This paper examine the relationship between auditory comprehension and verbal working memory indexed by eye-tracking in persons with aphasia. The auditory comprehension indexed used were the PALPA, MCTAC, and WAB. There were no significant relationships found between any of the auditory comprehension scores and the verbal working memory eye-tracking scores. Advisors/Committee Members: Hallowell, Dr. Brooke.

▼ The purpose of this study was to determine whether changes in bolus consistencies (thin liquid, nectar thick liquid, and puree) improve the safety of swallowing among poststroke patients with aspiration and without aspiration. Videofluoroscopic swallowing examinations (VFSEs) were obtained from 12 poststroke patients with aspiration and 12 poststroke patients without aspiration. VFSEs of each patient were analyzed for swallows of 5ml thin liquid, nectar thick liquid, and puree. The Penetration-Aspiration Scale (PA Scale) was used to rate the swallow on a scale of 1 to 8. Statistical comparisons were made by two-way analysis of variance (ANOVA) and the significance level was set at p < 0.05. For poststroke patients with aspiration, two bolus consistencies (thin liquid vs. nectar thick liquid and puree) had a significant effect on the PA Scale rating. However, for poststroke patients without aspiration, no significant differences were found among bolus consistencies. Clinical implications are discussed. Advisors/Committee Members: Kim, Dr. Youngsun.

▼ The purpose of this study was to determine the effects of age and gender on transition durations of thin and nectar thick liquids and puree swallows of normal subjects. For this study, temporal measurements were obtained from 40 normal subjects. The subjects were divided into two groups. This included 20 younger subjects (M age = 35.8) and 20 older subjects (M age = 74.5), with each age group consisting of 10 males and 10 females. The Videofluoroscopic Swallowing Examination (VFSE) of each subject was analyzed for two 5ml thin and nectar thick liquids, and one 5ml puree swallows. Two temporal measurements of oropharyngeal swallowing were measured: Oral Transition Time (OTT) and Pharyngeal Transition Time (PTT). Statistical comparisons were made by a three-way analysis of variance (ANOVA) and the significance level was set at p<0.05. Age and gender did not have a significant effect on the oral transition of the bolus. However, older subjects exhibited longer pharyngeal transition than younger subjects. Longer OTT and PTT were recorded in puree swallows than liquid swallows. Clinical implications are discussed. Advisors/Committee Members: Kim, Youngsun.