Monthly Archives: November 2009
Verb production and word order in Russian agrammatic speakers *
Background: Verb production has been shown to be impaired in individuals with agrammatic Broca’s aphasia. Several theories have linked this deficit to problems with the implementation of grammatical information that the verb contains. In particular, the number and type of arguments associated with a verb were suggested as causes of production difficulties in agrammatic speakers. The influence of these two factors on agrammatic production has been investigated in English and Dutch (Bastiaanse & Van Zonneveld, 2005; Thompson, 2003).
Aims: The present study focuses on exploring these factors in a structurally different language. Russian, with its rich morphology and relatively free word order, is of interest because it enables not only testing of earlier advanced hypotheses on agrammatic production, but also specification of them at some essential points.
Methods & Procedures: A sentence production priming paradigm was used that was based on the method developed by Thompson, Lange, Schneider, and Shapiro (1997) which allows a particular verb and sentence construction to be elicited. Six conditions included sentences with different numbers of arguments (one or two), different types of thematic role mapping (direct or indirect), and different word order (basic or scrambled). The test contained 60 items, 10 items per condition. In all, 16 individuals with agrammatic aphasia and 16 non-brain-damaged individuals participated in the study.
Outcomes & Results: Cross-linguistic significance of the earlier advanced hypotheses was demonstrated: the increased number of verb arguments and syntactic operations concerning constituent movement cause production problems for Russian agrammatic speakers. Moreover, the data show that agrammatic speech difficulties are related to the number of arguments explicitly mentioned in a sentence, to the number of operations applied to the syntactic structure of a produced sentence, and to changing the base-generated position of a constituent (not to the order of the constituents per se).
Conclusions: The study provides further evidence that verb production is selectively impaired in agrammatic aphasia. This deficit is related to the implementation of the grammatical information that a verb contains and the syntactic operations applied to basic structures.
* This study was financially supported by the Russian Foundation for Humanities (RGNF, Project N 08-04-00165a). The authors would like to thank Victor C. Dragoy for developing picture materials used in the study.
from Aphasiology
Two cultures, one programme: Deaf Professors as subaltern?
Deaf instructors of American Sign Language have taught ASL in formal institutions of higher learning for several decades now, yet little is known of the challenges they face within those contexts. In this study, interviews with instructors of five ASL – English Interpreter Programs (AEIP) and four Deaf Studies Programs (DSP) in Canada identified a number of common themes in particular to the intersection of culture, power, and identity. Within a post-colonial framework differences were found in the discursive practices of the participants as Deaf or non-Deaf individuals. Evidence of systemic audism experienced by the Deaf staff was noted at a number of levels, perhaps due to the existence of a Grand Narrative of Hearing and a process of Worlding based on the ideology of the hearing majority. As a result perhaps some of the Deaf instructors were ascribed or adopted the role of subaltern, where they should have instead experienced substantial social capital. Copyright © 2009 John Wiley & Sons, Ltd.
Chinese speech intelligibility at different speech sound pressure levels and signal-to-noise ratios in simulated classrooms
The speech intelligibility in classroom can be influenced by background-noise levels, speech sound pressure level (SSPL), reverberation time and signal-to-noise ratio (SNR). The relationship between SSPL and subjective Chinese Mandarin speech intelligibility and the effect of different SNRs on Chinese Mandarin speech intelligibility in the simulated classroom were investigated through room acoustical simulation, auralisation technique and subjective evaluation. Chinese speech intelligibility test signals recorded in anechoic chamber were convolved with the simulated binaural room impulse responses, and then reproduced through the headphone by different SSPLs and SNRs. The results show that Chinese Mandarin speech intelligibility scores increase with increasing of SSPLs and SNRs within a certain range in simulated classrooms. Chinese Mandarin speech intelligibility scores have no significant difference with SNRs of no less than 15 dBA under the same reverberation time condition.
from Applied Acoustics
Copyright © 2009 Published by Elsevier B.V. Performance Considerations of Prosthetic Actuators for Round-Window Stimulation
Round window (RW) stimulation has improved speech perception in patients with mixed hearing loss. In cadaveric temporal bones, we recently showed that RW stimulation with an active prosthesis produced differential pressure across the cochlear partition (a measure related to cochlear transduction) similar to normal forward sound stimulation above 1 kHz, when contact area between the prosthesis and RW is secured. However, there is large variability in the hearing improvement in patients implanted with existing modified prosthesis. This is likely because the middle-ear prosthesis used for RW stimulation was designed for a very different application.
In this paper we utilize recently developed experimental techniques that allow for the calculation of performance specifications for a RW actuator. In cadaveric human temporal bones (N=3), we simultaneously measure scala vestibuli and scala tympani intracochlear pressures, as well as stapes velocity and ear-canal pressure, during normal forward sound stimulation as well as reverse RW stimulation. We then calculate specifications such as the impedance the actuator will need to oppose at the RW, the force with which it must push against the RW, and the velocity and distance by which it must move the RW to obtain cochlear stimulation equivalent to that of specific levels of ear canal pressure under normal sound stimulation. This information is essential for adapting existing prostheses and for designing new actuators specifically for RW stimulation.
from Hearing Research
Fluency does not express implicit knowledge of artificial grammars
It is commonly held that implicit knowledge expresses itself as fluency. A perceptual clarification task was used to examine the relationship between perceptual processing fluency, subjective familiarity, and grammaticality judgments in a task frequently used to produce implicit knowledge, artificial grammar learning (AGL). Four experiments examined the effects of naturally occurring differences and manipulated differences in perceptual fluency, where decisions were based on a brief exposure to test-strings (during the clarification task only) or normal exposure. When perceptual fluency was not manipulated, it was weakly related to familiarity and grammaticality judgments, but unrelated to grammatical status and hence not a source of accuracy. Counterbalanced grammatical and ungrammatical strings did not differ in perceptual fluency but differed substantially in subjective familiarity. When fluency was manipulated, faster clarifying strings were rated as more familiar and were more often endorsed as grammatical but only where exposure was brief. Results indicate that subjective familiarity derived from a source other than perceptual fluency, is the primary basis for accuracy in AGL. Perceptual fluency is found to be a dumb heuristic influencing responding only in the absence of actual implicit knowledge.
from Cognition
Sound Categorization and Conceptual Priming for Nonlinguistic and Linguistic Sounds
The aim of these experiments was to compare conceptual priming for linguistic and for a homogeneous class of nonlinguistic sounds, impact sounds, by using both behavioral (percentage errors and RTs) and electrophysiological measures (ERPs). Experiment 1 aimed at studying the neural basis of impact sound categorization by creating typical and ambiguous sounds from different material categories (wood, metal, and glass). Ambiguous sounds were associated with slower RTs and larger N280, smaller P350/P550 components, and larger negative slow wave than typical impact sounds. Thus, ambiguous sounds were more difficult to categorize than typical sounds. A category membership task was used in Experiment 2. Typical sounds were followed by sounds from the same or from a different category or by ambiguous sounds. Words were followed by words, pseudowords, or nonwords. Error rate was highest for ambiguous sounds and for pseudowords and both elicited larger N400-like components than same typical sounds and words. Moreover, both different typical sounds and nonwords elicited P300 components. These results are discussed in terms of similar conceptual priming effects for nonlinguistic and linguistic stimuli.
from the Journal of Cognitive Neuroscience
Dysphagia in spinal muscular atrophy type II
Conclusions: Dysphagia in spinal muscular atrophy type II is due to a neurologic dysfunction (lower motor neuron problems from the cranial nerves in the brainstem) influencing the muscle force and efficiency of movement of the tongue and the submental muscle group in combination with a biomechanical component (compensatory head posture). The results suggest an integrated treatment with an adapted posture during meals and the advice of drinking water after meals to prevent aspiration pneumonias.
from Neurology
Neural Changes Associated with Nonspeech Auditory Category Learning Parallel Those of Speech Category Acquisition
Native language experience plays a critical role in shaping speech categorization, but the exact mechanisms by which it does so are not well understood. Investigating category learning of nonspeech sounds with which listeners have no prior experience allows their experience to be systematically controlled in a way that is impossible to achieve by studying natural speech acquisition, and it provides a means of probing the boundaries and constraints that general auditory perception and cognition bring to the task of speech category learning. In this study, we used a multimodal, video-game-based implicit learning paradigm to train participants to categorize acoustically complex, nonlinguistic sounds. Mismatch negativity responses to the nonspeech stimuli were collected before and after training to investigate the degree to which neural changes supporting the learning of these nonspeech categories parallel those typically observed for speech category acquisition. Results indicate that changes in mismatch negativity resulting from the nonspeech category learning closely resemble patterns of change typically observed during speech category learning. This suggests that the often-observed “specialized” neural responses to speech sounds may result, at least in part, from the expertise we develop with speech categories through experience rather than from properties unique to speech (e.g., linguistic or vocal tract gestural information). Furthermore, particular characteristics of the training paradigm may inform our understanding of mechanisms that support natural speech acquisition.
from the Journal of Cognitive Neuroscience
Concept Selection and Developmental Effects in Bilingual Speech Production
The present study investigates the locus of language selection in less and more proficient language learners, specifically testing differential predictions of La Heij’s (2005) concept selection model (CSM) and Kroll and Stewart’s (1994) revised hierarchical model (RHM). Less and more proficient English dominant learners of Spanish participated in a Stroop translation task that included semantically related and unrelated word or picture distracters. The results for the more proficient learners provide support for the CSM as well as the RHM. The results for the less proficient learners provide support for the RHM and demonstrate the continued reliance on lexical level links and the difficulty in accessing the conceptual store during second language production. The selection by proficiency model of bilingual speech production is discussed.
from Language Learning
Native Speakers and Task Performance: Comparing Effects on Complexity, Fluency, and Lexical Diversity
This article argues that a native-speaker baseline is a neglected dimension of studies into second language (L2) performance. If we investigate how learners perform language tasks, we should distinguish what performance features are due to their processing an L2 and which are due to their performing a particular task. Having defined what we mean by “native speaker,” we present the background to a research study into task features on nonnative task performance, designed to include native-speaker data as a baseline for interpreting nonnative-speaker performance. The nonnative results, published in this journal (Tavakoli & Foster, 2008) are recapitulated and then the native-speaker results are presented and discussed in the light of them. The study is guided by the assumption that limited attentional resources impact on L2 performance and explores how narrative design features—namely complexity of storyline and tightness of narrative structure—affect complexity, fluency, accuracy, and lexical diversity in language. The results show that both native and nonnative speakers are prompted by storyline complexity to use more subordinated language, but narrative structure had different effects on native and nonnative fluency. The learners, who were based in either London or Tehran, did not differ in their performance when compared to each other, except in lexical diversity, where the learners in London were close to native-speaker levels. The implications of the results for the applicability of Levelt’s model of speaking to an L2 are discussed, as is the potential for further L2 research using native speakers as a baseline.
from Language Learning
Assessing progress during treatment for young children with autism receiving intensive behavioural interventions
This study examined progress after 1 year of treatment for children with autism who received a mean of 36 hours per week one-to-one University of California at Los Angeles Applied Behavior Analysis (UCLA ABA) treatment. Two types of service provision were compared: an intensive clinic based treatment model with all treatment personnel (N = 23), and an intensive parent managed treatment model with intensive supervision only (N = 21). A non-concurrent multiple baseline design across participants (N = 13) examined whether progress was associated with ABA treatment or confounders. Between intake and follow-up, children in both groups improved significantly on IQ, visual-spatial IQ, language comprehension, expressive language, social skills, motor skills and adaptive behaviour. There were no significant differences between the two groups on any of the measures at follow-up. Mean IQ for participants in both groups increased by 16 points between intake and follow-up. These findings are consistent with previous studies demonstrating the benefits of ABA treatment.
from Autism
Analysis of Auditory Measures in Normal Hearing Young Male Adult Cigarette Smokers Using Multiple Variable Selection Methods with Predictive Validation Assessments
Studies have shown that cigarette smoking is a risk factor for hearing loss; however, no information is available on auditory preclinical indicators in young chronic cigarette smokers. Cigarette smoking involves exposure to many harmful chemicals including carbon monoxide (CO). In this study, the CO level in 16 young normal hearing male chronic smokers was measured with a CO monitor, and was used as the outcome measure. Subjects were administered a battery of audiological tests that included behavioral and electrophysiologic measures. The goal was to investigate which auditory test measures can be used as potential predictors of the outcome measure. Using ordinary least squares estimation procedures with best-subsets selection and bootstrapped stepwise variable selection procedures, an optimal predictive multiple linear regression model was selected. Results of this approach indicated that auditory brainstem response peak V amplitudes and distortion product otoacoustic emissions had the highest predictive value and accounted for most of the variability.
Gender-specific associations of vision and hearing impairments with adverse health outcomes in older Japanese: a population-based cohort study
Conclusions
In this older Japanese population, sensory impairments were clearly associated with AHOs, and the association appeared to vary according to gender. Gender-specific associations between sensory impairments and AHOs warrant further investigation.
from BMC Geriatrics
The effect of tightened hearing protection regulations on military noise-induced tinnitus.
The objective of this study was to investigate the effect of tightened hearing protection regulations on tinnitus in the Finnish Defence Forces. The initial study group comprised 252 officers and non-commissioned officers (NCOs), of which 229 were included in the final study group. Subjective symptoms of tinnitus and audiometric test results for these officers and NCOs examined before retirement, from 1984 to 1986 (Period I), and 2003 to 2005 (Period II), were reviewed. Changes in tinnitus reports between the two time periods, during which regulations had been revised, were investigated. Prevalence of tinnitus showed a decline both in officers (from 68% to 63%) and in NCOs (from 76% to 72%) between the two study periods, in accordance with tightened hearing protection regulations. The Cox regression analysis showed a significantly decreased hazard ratio for constant or disturbing tinnitus for Period II. Tinnitus prevalence, especially constant or disturbing tinnitus, in the Finnish Defence Forces was diminished by tightened hearing protection regulations. Tinnitus might be more persistent than hearing loss and does not necessarily improve in direct relation to hearing loss after protective measures.
from the International Journal of Audiology
What Automated Vocal Analysis Reveals About the Vocal Production and Language Learning Environment of Young Children with Autism
Abstract The study compared the vocal production and language learning environments of 26 young children with autism spectrum disorder (ASD) to 78 typically developing children using measures derived from automated vocal analysis. A digital language processor and audio-processing algorithms measured the amount of adult words to children and the amount of vocalizations they produced during 12-h recording periods in their natural environments. The results indicated significant differences between typically developing children and children with ASD in the characteristics of conversations, the number of conversational turns, and in child vocalizations that correlated with parent measures of various child characteristics. Automated measurement of the language learning environment of young children with ASD reveals important differences from the environments experienced by typically developing children.
