Monthly Archives: July 2010
Early and late talkers: school-age language, literacy and neurolinguistic differences
Early language development sets the stage for a lifetime of competence in language and literacy. However, the neural mechanisms associated with the relative advantages of early communication success, or the disadvantages of having delayed language development, are not well explored. In this study, 174 elementary school-age children whose parents reported that they started forming sentences ‘early’, ‘on-time’ or ‘late’ were evaluated with standardized measures of language, reading and spelling. All oral and written language measures revealed consistent patterns for ‘early’ talkers to have the highest level of performance and ‘late’ talkers to have the lowest level of performance. We report functional magnetic resonance imaging data from a subset of early, on-time and late talkers matched for age, gender and performance intelligence quotient that allows evaluation of neural activation patterns produced while listening to and reading real words and pronounceable non-words. Activation in bilateral thalamus and putamen, and left insula and superior temporal gyrus during these tasks was significantly lower in late talkers, demonstrating that residual effects of being a late talker are found not only in behavioural tests of oral and written language, but also in distributed cortical-subcortical neural circuits underlying speech and print processing. Moreover, these findings suggest that the age of functional language acquisition can have long-reaching effects on reading and language behaviour, and on the corresponding neurocircuitry that supports linguistic function into the school-age years.
from Brain
Writing errors as a result of frontal dysfunction in Japanese patients with amyotrophic lateral sclerosis
Loss of communication is a critical problem for advanced amyotrophic lateral sclerosis (ALS) patients. This loss of communication is mainly caused by severe dysarthria and disability of the dominant hand. However, reports show that about 50% of ALS patients have mild cognitive dysfunction, and there are a considerable number of case reports on Japanese ALS patients with agraphia. To clarify writing disabilities in non-demented ALS patients, eighteen non-demented ALS patients and 16 controls without neurological disorders were examined for frontal cognitive function and writing ability. To assess writing errors statistically, we scored them on their composition ability with the original writing error index (WEI). The ALS and control groups did not differ significantly with regard to age, years of education, or general cognitive level. Two patients could not write a letter because of disability of the dominant hand. The WEI and results of picture arrangement tests indicated significant impairment in the ALS patients. Auditory comprehension (Western Aphasia Battery; WAB IIC) and kanji dictation also showed mild impairment. Patients’ writing errors consisted of both syntactic and letter-writing mistakes. Omission, substitution, displacement, and inappropriate placement of the phonic marks of kana were observed; these features have often been reported in Japanese patients with agraphia resulted from a frontal lobe lesion. The most frequent type of error was an omission of kana, the next most common was a missing subject. Writing errors might be a specific deficit for some non-demented ALS patients.
from the Journal of Neurology
Objective and Subjective Psychophysical Measures of Auditory Stream Integration and Segregation
The perceptual organization of sound sequences into auditory streams involves the integration of sounds into one stream and the segregation of sounds into separate streams. “Objective” psychophysical measures of auditory streaming can be obtained using behavioral tasks where performance is facilitated by segregation and hampered by integration, or vice versa. Traditionally, these two types of tasks have been tested in separate studies involving different listeners, procedures, and stimuli. Here, we tested subjects in two complementary temporal-gap discrimination tasks involving similar stimuli and procedures. One task was designed so that performance in it would be facilitated by perceptual integration; the other, so that performance would be facilitated by perceptual segregation. Thresholds were measured in both tasks under a wide range of conditions produced by varying three stimulus parameters known to influence stream formation: frequency separation, tone-presentation rate, and sequence length. In addition to these performance-based measures, subjective judgments of perceived segregation were collected in the same listeners under corresponding stimulus conditions. The patterns of results obtained in the two temporal-discrimination tasks, and the relationships between thresholds and perceived-segregation judgments, were mostly consistent with the hypothesis that stream segregation helped performance in one task and impaired performance in the other task. The tasks and stimuli described here may prove useful in future behavioral or neurophysiological experiments, which seek to manipulate and measure neural correlates of auditory streaming while minimizing differences between the physical stimuli.
from JARO — Journal of the Association for Research in Otolaryngology
Delirium in Elderly Patients and the Risk of Postdischarge Mortality, Institutionalization, and Dementia
Conclusion This meta-analysis provides evidence that delirium in elderly patients is associated with poor outcome independent of important confounders, such as age, sex, comorbid illness or illness severity, and baseline dementia.
Meta-analysis in Second Language Research: Choices and Challenges
Applied linguists are increasingly conducting meta-analysis in their substantive domains, because as a quantitative approach for averaging effect sizes across studies, it is more systematic and replicable than traditional, qualitative literature reviews. Additional strengths, such as increased statistical power, moderator analyses, and model testing, have also contributed to its appeal. The current review describes typical stages of a meta-analysis in second language acquisition (SLA) research: (a) defining the research domain, (b) developing a reliable coding scheme, (c) analyzing data, and (d) interpreting results. Each stage has a host of equally reasonable decisions that can be made; each decision will influence the conduct of the meta-analysis, the nature of the results, and the substantive implications of findings for SLA. We highlight a number of benefits and challenges that inform these decisions. In general, when a meta-analysis in applied linguistics is well planned, employs sound statistical methods, and is based on a thorough understanding of relevant theory, it can provide critical information that informs theory as well as future research, practice, and policy.
from the Annual Review of Applied Linguistics
Second Language Acquisition and Syntactic Theory in the 21st Century
Syntactic theory has played a role in second language acquisition (SLA) research since the early 1980s, when the principles and parameters model of generative grammar was implemented. However, it was the so-called functional parameterization hypothesis together with the debate on whether second language learners activated new features or switched their value that led to detailed and in-depth analyses of the syntactic properties of many different nonnative grammars. In the last 10 years, with the minimalist program as background, these analyses have diverted more and more from looking at those syntactic properties that argued for or against the various versions of the UG-access versus non-UG-access debate (UG for Universal Grammar) and have more recently delved into the status of nonnative grammars in the cognitive science field. Thus, using features (i.e., gender, case, verb, and determiner) as the basic units and paying special attention to the quality of input as well as to processing principles and constraints, nonnative grammars have been compared to the language contact paradigms that underlie subsequent bilingualism, child SLA, creole formation, and diachronic change. Taking Chomsky’s I-language/E-language construct as the framework, this article provides a review of these recent developments in SLA research.
from the Annual Review of Applied Linguistics
Semantic Theory and Second Language Acquisition
The article identifies four different types of meaning situated in different modules of language. Such a modular view of language architecture suggests that there may be differential difficulties of acquisition for the different modules. It is argued that second language (L2) acquisition of meaning involves acquiring interpretive mismatches at the first and second language (L1-L2) syntax-semantics interfaces. In acquiring meaning, learners face two types of learning situations. One situation where the sentence syntax presents less difficulty but different pieces of functional morphology subsume different primitives of meaning is dubbed simple syntax–complex semantics. Another type of learning situation is exemplified in less frequent, dispreferred, or syntactically complex sentences where the sentential semantics offers no mismatch; these are labeled complex syntax–simple semantics. Studies representative of these learning situations are reviewed. The issues of importance of explicit instruction with respect to interpretive properties and the effect of the native language are addressed. Studies looking at acquisition of language-specific discourse properties and universal pragmatics are also reviewed. These representative studies and numerous other studies on the L2 acquisition of meaning point to no visible barrier to ultimate success in the acquisition of semantics and pragmatics.
from the Annual Review of Applied Linguistics
Increased activity of Diaphanous homolog 3 (DIAPH3)/diaphanous causes hearing defects in humans with auditory neuropathy and in Drosophila
Auditory neuropathy is a rare form of deafness characterized by an absent or abnormal auditory brainstem response with preservation of outer hair cell function. We have identified Diaphanous homolog 3 (DIAPH3) as the gene responsible for autosomal dominant nonsyndromic auditory neuropathy (AUNA1), which we previously mapped to chromosome 13q21-q24. Genotyping of additional family members narrowed the interval to an 11-Mb, 3.28-cM gene-poor region containing only four genes, including DIAPH3. DNA sequencing of DIAPH3 revealed a c.-172G > A, g. 48G > A mutation in a highly conserved region of the 5′ UTR. The c.-172G > A mutation occurs within a GC box sequence element and was not found in 379 controls. Using genome-wide expression arrays and quantitative RT-PCR, we demonstrate a 2- to 3-fold overexpression of DIAPH3 mRNA in lymphoblastoid cell lines from affected individuals. Likewise, a significant increase (≈1.5-fold) in DIAPH3 protein was found by quantitative immunoblotting of lysates from lymphoblastoid cell lines derived from affected individuals in comparison with controls. In addition, the c.-172G > A mutation is sufficient to drive overexpression of a luciferase reporter. Finally, the expression of a constitutively active form of diaphanous protein in the auditory organ of Drosophila melanogaster recapitulates the phenotype of impaired response to sound. To date, only two genes, the otoferlin gene OTOF and the pejvakin gene PJVK, are known to underlie nonsyndromic auditory neuropathy. Genetic testing for DIAPH3 may be useful for individuals with recessive as well as dominant inheritance of nonsyndromic auditory neuropathy.
from the Proceedings of the National Academy of Sciences of the United States of America
Automated vocal analysis of naturalistic recordings from children with autism, language delay, and typical development
For generations the study of vocal development and its role in language has been conducted laboriously, with human transcribers and analysts coding and taking measurements from small recorded samples. Our research illustrates a method to obtain measures of early speech development through automated analysis of massive quantities of day-long audio recordings collected naturalistically in children’s homes. A primary goal is to provide insights into the development of infant control over infrastructural characteristics of speech through large-scale statistical analysis of strategically selected acoustic parameters. In pursuit of this goal we have discovered that the first automated approach we implemented is not only able to track children’s development on acoustic parameters known to play key roles in speech, but also is able to differentiate vocalizations from typically developing children and children with autism or language delay. The method is totally automated, with no human intervention, allowing efficient sampling and analysis at unprecedented scales. The work shows the potential to fundamentally enhance research in vocal development and to add a fully objective measure to the battery used to detect speech-related disorders in early childhood. Thus, automated analysis should soon be able to contribute to screening and diagnosis procedures for early disorders, and more generally, the findings suggest fundamental methods for the study of language in natural environments.
from the Proceedings of the National Academy of Sciences of the United States of America
Influences on parental evaluation of the content of early intervention following early identification of deafness: a study about parents’ preferences and satisfaction
Conclusion These findings underscore the importance of understanding how parents’ beliefs, values and perceived need impact on their experience of early intervention
Disentangling the social threads within a communicative environment: a cacophonous tale of alternative and augmentative communication (AAC)
Alternative and augmentative communication (AAC) technology is being increasingly recognised as an important means of fostering the literacy of students with significant disabilities. However, the coordinated use of AAC technology continues to challenge professionals, families and users leading to dissonant meanings and fragmented use. This paper is an attempt to inquire into, and disentangle some of, the social threads that made up the communicative environment of one first-grade student with significant disabilities – Trevor – for whom augmentative communication technology was procured. The ethnographic study reported in this paper documents the conflicting meanings of access and participation that surfaced among the multiple participants under whose guidance Trevor was required to use AAC. The paper discloses the assumptions implicit in these practices and in the conceptions of literacy enacted by different professionals. The paper notes the significance of these issues for Trevor’s narrative construction of himself and concludes with implications for practitioners.
A comparison of the McGurk effect for spoken and sung syllables
The importance of visual cues in speech perception is illustrated by the McGurk effect, whereby a speaker’s facial movements affect speech perception. The goal of the present study was to evaluate whether the McGurk effect is also observed for sung syllables. Participants heard and saw sung instances of the syllables /ba/ and /ga/ and then judged the syllable they perceived. Audio–visual stimuli were congruent or incongruent (e.g., auditory /ba/ presented with visual /ga/). The stimuli were presented as spoken, sung in an ascending and descending triad (C E G G E C), and sung in an ascending and descending triad that returned to a semitone above the tonic (C E G G E C#). Results revealed no differences in the proportion of fusion responses between spoken and sung conditions confirming that cross-modal phonemic information is integrated similarly in speech and song.
Alignment to visual speech information
Speech alignment is the tendency for interlocutors to unconsciously imitate one another’s speaking style. Alignment also occurs when a talker is asked to shadow recorded words (e.g., Shockley, Sabadini, & Fowler, 2004). In two experiments, we examined whether alignment could be induced with visual (lipread) speech and with auditory speech. In Experiment 1, we asked subjects to lipread and shadow out loud a model silently uttering words. The results indicate that shadowed utterances sounded more similar to the model’s utterances than did subjects’ nonshadowed read utterances. This suggests that speech alignment can be based on visual speech. In Experiment 2, we tested whether raters could perceive alignment across modalities. Raters were asked to judge the relative similarity between a model’s visual (silent video) utterance and subjects’ audio utterances. The subjects’ shadowed utterances were again judged as more similar to the model’s than were read utterances, suggesting that raters are sensitive to cross-modal similarity between aligned words.
Auditory, tactile, and multisensory cues facilitate search for dynamic visual stimuli
Presenting an auditory or tactile cue in temporal synchrony with a change in the color of a visual target can facilitate participants’ visual search performance. In the present study, we compared the magnitude of unimodal auditory, vibrotactile, and bimodal (i.e., multisensory) cuing benefits when the nonvisual cues were presented in temporal synchrony with the changing of the target’s color (Experiments 1 and 2). The target (a horizontal or vertical line segment) was presented among a number of distractors (tilted line segments) that also changed color at various times. In Experiments 3 and 4, the cues were also made spatially informative with regard to the location of the visual target. The unimodal and bimodal cues gave rise to an equivalent (significant) facilitation of participants’ visual search performance relative to a no-cue baseline condition. Making the unimodal auditory and vibrotactile cues spatially informative produced further performance improvements (on validly cued trials), as compared with cues that were spatially uninformative or otherwise spatially invalid. A final experiment was conducted in order to determine whether cue location (close to versus far from the visual display) would influence participants’ visual search performance. Auditory cues presented close to the visual search display were found to produce significantly better performance than cues presented over headphones. Taken together, these results have implications for the design of nonvisual and multisensory warning signals used in complex visual displays.
Decomposing the Garner interference paradigm: Evidence for dissociations between macrolevel and microlevel performance
Three Garner interference experiments are described in which baseline, filtering, and correlated performance were assessed at both a macrolevel (condition average) and microlevel (intertrial contingency), using the pair-wise combinations of auditory pitch, loudness, and location. Discrepancies between pairs of dimensions were revealed between macro- and microlevel estimates of performance and, also, between filtering costs and correlated benefits, relative to baseline. The examination of the intertrial effects associated with filtering costs suggested that effects of increased stimulus uncertainty were mandatory, whereas effects of irrelevant variation were not. The examination of the intertrial effects associated with correlated benefits suggested that the detection of stimulus repetition took precedence over that of stimulus change. Violations of standard horse race accounts of processing did not appear to stem from differences in the absolute or relative speeds of processing between dimensions but, rather, from the special role that certain dimensions (e.g., pitch) may play in certain modalities (e.g., audition). The utility of examining repetition effects is demonstrated by revealing a level of understanding regarding stimulus processing typically hidden by aggregated measures of performance.
