No description available.

Children with Tourette Syndrome (CWTS) frequently exhibit a high prevalence of disfluent speech behaviors which are often labeled stuttering. The present study analyzed the fluency characteristics of CWTS, in comparison to children who stutter (CWS) and typically developing peers (TDP). It was predicted that CWTS would be less fluent than TDP but more fluent than CWS. A related purpose was to explore whether differences existed in the pattern of disfluencies demonstrated by these groups. To this end, it was predicted that CWTS would demonstrate significantly lower proportions of stuttering-like disfluencies than CWS and significantly higher proportions of stuttering-like disfluencies than TDP. Participants included eight CWTS, eight CWS and eight TDP. Speech samples, collected during a narrative story telling task, were analyzed to determine whether significant differences in the type and frequency of disfluencies were evident between the groups. Results revealed that CWTS were significantly more fluent than CWS and that CWTS produced significantly lower proportions of stuttering-like disfluencies than CWS. Although not statistically significant, CWTS were twice as disfluent as TDP and CWTS produced significantly higher proportions of stuttering-like disfluencies than TDP. These findings confirmed that CWTS present with an atypical disfluency pattern which can be differentiated from that of CWS and TDP based on the total disfluency level and the proportion of stuttering-like disfluencies. / Communication Sciences

No description available.

No description available.

Speech is the tool humans use to communicate that sets us apart from any other species. It is a complex interplay between the motor speech system of the speaker and the auditory system of the listener. Self-monitoring uses what one hears to help monitor what one says by way of an automatic feedback loop. We tested the theory that humans are selectively adaptive to acoustic stimuli that contain speech-like frequencies. In Study One, we measured speech output changes given speech versus noise masks during a naming task. Results showed that noise containing speech-similar frequencies (broadband, 0.0--20 kHz; bandpassed, 0.05--4.5 kHz; high-notched, 8.0--11.5 kHz removed) elicited significant changes in the acoustic features of the speech output, while noise with speech-similar frequencies removed (low-notched, 0.5--4.5 kHz removed) did not. In Study Two, we measured duration matching accuracy, and speech output changes given speech and noise masks during a novel duration matching task. Participants matched /a/, /f/, and noise at 300 ms, 550 ms, and 800 ms lengths in quiet, speech (/a/, /i/), broadband noise, and /f/-frequency shaped noise masks. Findings showed that it was more difficult to duration match /a/ given a speech versus a noise mask. In addition, there were different error patterns between speech and noise; speech targets were overshot with error greatest at 550 ms, while noise targets were undershot with error increasing as target length increased. Collectively, results support the theory that self-monitoring in humans is selectively affected by frequencies within the speech range and that a specialized module exists for processing speech information / acase@tulane.edu

acase@tulane.edu

Memory deficits are considered the hallmark of Alzheimer's disease and indices of episodic memory and learning are critical in early identification of AD. Poor performance on episodic memory tests precedes detectable clinical change and global psychometric deterioration in individuals who develop AD. Performance on delayed story recall tasks is a sensitive measure of memory impairments associated with dementia. This task involves presenting a short story auditorily which subjects recall immediately and at different time delays. However, there is limited information on the effects of encoding conditions on this task. Given the high prevalence of hearing loss in older adults, administering a story recall task via auditory presentation may not enable optimal encoding of information. This could lead to spuriously poor performance on memory tests, an overlooked consideration when testing older adults. The primary purpose of this study was to determine how varying encoding conditions influence story recall in healthy, older adults and those with AD. A secondary purpose was to investigate recognition abilities and learning effects in dementia patients. All participants were administered a story recall task (comprising three stories) in three modalities: (1) auditory, (2) visual (silent reading), and (3) auditory and visual. Free recall was assessed immediately, and at delays of 15 and 30 minutes. Following recall at 30 minutes, half of the healthy elders and AD participants were given a multiple-choice recognition task and the stories were repeated for the other half. After repetition, story recall was assessed immediately and after 15 minutes. Three noteworthy findings emerged from this study. First, the AD participants recalled a story best after silently reading the story, compared to hearing an examiner tell the story, or simultaneously hearing and reading the story. Second, testing recognition memory with a multiple-choice test revealed that AD patients could recognize information which they could not freely recall. Finally, both AD patients and normal elders improved their free recall of stories after they were presented a second time. These results have important implications for assessing and managing memory deficits in healthy elders and those with AD.

Theory of mind has seldom been studied in normal elders (NE) or people with aphasia (APH), and has never been studied in people with Alzheimer Disease (AD). This study, based on Miller (2001), investigated false belief attribution in 10 APH, 10 AD, and 10 NE subjects. Three conditions of the false belief task varied syntactically to probe for an interaction between linguistic demand and false belief performance. Relative to normal elders, AD subjects showed impairment in false belief attribution (p < 0.001); APH subjects did not (p = 1.0). There was no effect of linguistic demand for any group. Potential confounding variables (e.g. immediate memory) were nonsignificant. The data suggest a possible nonlinear relationship between false belief attribution and measures of dementia severity and frontal lobe function. The results also suggest methods for comparing theories of theory of mind in future research.

<p> The field of research in bilingualism and second language (L2) acquisition has yielded overwhelming evidence that acquiring a second language later in life will result in less accurate production and perception of consonants and vowels in the second language. These effects, in part, are a result of interference from the already formed phonetic categories shaped by early exposure to the L1 (Iverson, 2007). Phonetic categories from the L2 will, at least initially, be mapped onto phonetic categories from the L1 (Flege, 1995). Shared storage of similar lexical items from L1 and L2 may also take place resulting in differences in processing for words with similar meanings in both languages with similar meanings. Language learners of any age are able to acquire a limitless number of new vocabulary items in their L2. Whether similarities in orthography and/or phonology of semantically similar words affect access to and comprehension of these new L2 lexical items is still unclear. Another question is whether lexical items that differ only in a non-native sound contrast are processed as good or poor exemplars of the L2 word, as a poor exemplar of the L1 word, or as allophonic variation of the L2 word. </p><p> In this dissertation neural correlates of L2 words that have or do not have L1 cognates were examined. A group of monolingual English speakers and a group of late Spanish-English bilinguals were asked to decide whether pairs of cognate and non-cognate words were produced the same or differently. Words were pronounced in Standard English or with a change in the production of the stressed vowel in the word to a vowel more similar to a Spanish phoneme. The results revealed that cognate words seemed to facilitate L2 speech discrimination as evidenced by similar responses by bilinguals and monolinguals to these words and smaller or absent responses by bilingual participants to non-cognate words. This facilitation was in the form of a positive ERP response elicited by the frontal electrodes. These results provide a better understanding of why there are mispronunciations and misperceptions of lexical items in an L2 and how shared meaning influences these processes.</p>

This work begins by examining the history of aphasia studies, placing them in the context of historically concurrent theories about speech and language. The historical analysis can be read as a deconstructive incision into contemporary discourses which use information about language to make inferences about brain functioning or thought processes. A deconstructive critique of aphasiology and those sciences upon which it is built, including linguistics and localization theory, suggests that aphasia is constructed artificially so that it cannot be localized or explained by brain mechanisms. Anthropological influences in this work inform the style of analysis as well as the range of inquiry. Situated in postmodern anthropology, the thesis includes an investigation of positioning: positioning of the author within medicine (neurology) and anthropology; and positioning as a phenomenon brought about by certain sets of practices. Among these practices are those related to the scientific method and those related to more interpretive or hermeneutic strategies. Several controversies within anthropology are related to the clash between science and not-science, including feminist and postmodern debates. Practices, which are situation-dependent, are not as conflicted as theories are and provide reasonable ways to separate sense (or meaningfulness) from non-sense (or artifacts) in daily life and work. Related to questions of method and interpretation are questions about "data." What count(s) as data? Should units of significance be predetermined, or discovered in the process of investigation? How do standardized methodologies or interpretive expectations shape the outcome of clinical, scientific, and anthropological studies? A narrative style is employed to discuss these questions by telling particular stories involving research and publication: case reports in neurology; semantics of sentence accent in Alzheimer's disease; and fieldwork in northern Thailand concerning nonliteracy and its effects on cognitive processes among Karen hilltribes. These disciplinary projects are contrasted and data creation discussed. What began as an examination of the history of aphasia studies concludes in discussion of aphasic speech as an example/critique of postmodern and anthropological discourse. Practices that cluster around the study of aphasia, particularly those involving living patients, provide useful critiques to scientific, anthropological and postmodern theorizations.