Monthly Archives: May 2009
Reading, dyslexia and the brain
Conclusions: Different neuroimaging methods can contribute different kinds of data relevant to key questions in education. The most informative studies with respect to causation will be longitudinal prospective studies, which are currently rare.
from Educational Research
Laughter Differs in Children with Autism: An Acoustic Analysis of Laughs Produced by Children With and Without the Disorder
Abstract Few studies have examined vocal expressions of emotion in children with autism. We tested the hypothesis that during social interactions, children diagnosed with autism would exhibit less extreme laugh acoustics than their nonautistic peers. Laughter was recorded during a series of playful interactions with an examiner. Results showed that children with autism exhibited only one type of laughter, whereas comparison participants exhibited two types. No group differences were found for laugh duration, mean fundamental frequency (F0) values, change in F0, or number of laughs per bout. Findings are interpreted to suggest that children with autism express laughter primarily in response to positive internal states, rather than using laughter to negotiate social interactions.
Long-term symptoms in dizzy patients examined in a university clinic
Conclusion
The majority of patients had persistent and severe problems with dizziness. The wait-and-see attitude before referral to specialist institutions may be questioned. Early, active movements seem necessary, and attention should be paid to the presence of neck pain. Diagnoses had limited prognostic value. Questionnaire-based evaluations could assist in classification and identification of type of dizziness and thereby provide a better basis for specific rehabilitation.
Vocal fold surgery of benign inflammatory lesions of Reinke’s space: an outcome study in 47 subjects
Abstract Phonosurgery should lead to a better voice quality and a better quality of life. Only a few studies report outcome of phonosurgery in terms of stroboscopic, perceptual, aerodynamic, acoustic and self-rating data. The protocol as proposed by the European Laryngological Society (ELS; Dejonckere et al. in Arch Otorhinolaryngol 258:77–82, 2001) complies with this condition. A group of 47 patients who underwent phonosurgery was pre- and postoperatively assessed by means of the ELS protocol in order to evaluate postoperative outcome. Analysis of the data showed a significant improvement for all dimensions measured by stroboscopic parameters (glottic closure, mucosal wave, regularity and symmetry), perceptual voice quality (GRBAS), voice handicap index and the dysphonia severity index which represents both aerodynamic as acoustical measurements. In general, the significant improvement for a subgroup of exudative lesions of Reinke’s space is more pronounced than for a subgroup with structural/congenital lesions.
The Interrelations between Verbal Working Memory and Visual Selection of Emotional Faces
Working memory (WM) and visual selection processes interact in a reciprocal fashion based on overlapping representations abstracted from the physical characteristics of stimuli. Here, we assessed the neural basis of this interaction using facial expressions that conveyed emotion information. Participants memorized an emotional word for a later recognition test and then searched for a face of a particular gender presented in a display with two faces that differed in gender and expression. The relation between the emotional word and the expressions of the target and distractor faces was varied. RTs for the memory test were faster when the target face matched the emotional word held in WM (on valid trials) relative to when the emotional word matched the expression of the distractor (on invalid trials). There was also enhanced activation on valid compared with invalid trials in the lateral orbital gyrus, superior frontal polar (BA 10), lateral occipital sulcus, and pulvinar. Re-presentation of the WM stimulus in the search display led to the earlier onset of activity in the superior and inferior frontal gyri and the anterior hippocampus irrespective of the search validity of the re-presented stimulus. The data indicate that the middle temporal and prefrontal cortices are sensitive to the reappearance of stimuli that are held in WM, whereas a fronto-thalamic occipital network is sensitive to the behavioral significance of the match between WM and targets for selection. We conclude that these networks are modulated by high-level matches between the contents of WM, the behavioral goals, and our current sensory input.
from the Journal of Cognitive Neuroscience
Arabic Morphology in the Neural Language System
There are two views about morphology, the aspect of language concerned with the internal structure of words. One view holds that morphology is a domain of knowledge with a specific type of neurocognitive representation supported by specific brain mechanisms lateralized to left fronto-temporal cortex. The alternate view characterizes morphological effects as being a by-product of the correlation between form and meaning and where no brain area is predicted to subserve morphological processing per se. Here we provided evidence from Arabic that morphemes do have specific memory traces, which differ as a function of their functional properties. In an MMN study, we showed that the abstract consonantal root, which conveys semantic meaning (similarly to monomorphemic content words in English), elicits an MMN starting from 160 msec after the deviation point, whereas the abstract vocalic word pattern, which plays a range of grammatical roles, elicits an MMN response starting from 250 msec after the deviation point. Topographically, the root MMN has a symmetric fronto-central distribution, whereas the word pattern MMN lateralizes significantly to the left, indicating stronger involvement of left peri-sylvian areas. In languages with rich morphologies, morphemic processing seems to be supported by distinct neural networks, thereby providing evidence for a specific neuronal basis for morphology as part of the cerebral language machinery.
from the Journal of Cognitive Neuroscience
Training the Brain to Weight Speech Cues Differently: A Study of Finnish Second-language Users of English
Foreign-language learning is a prime example of a task that entails perceptual learning. The correct comprehension of foreign-language speech requires the correct recognition of speech sounds. The most difficult speech–sound contrasts for foreign-language learners often are the ones that have multiple phonetic cues, especially if the cues are weighted differently in the foreign and native languages. The present study aimed to determine whether non-native-like cue weighting could be changed by using phonetic training. Before the training, we compared the use of spectral and duration cues of English /i/ and /I/ vowels (e.g., beat vs. bit) between native Finnish and English speakers. In Finnish, duration is used phonologically to separate short and long phonemes, and therefore Finns were expected to weight duration cues more than native English speakers. The cross-linguistic differences and training effects were investigated with behavioral and electrophysiological methods, in particular by measuring the MMN brain response that has been used to probe long-term memory representations for speech sounds. The behavioral results suggested that before the training, the Finns indeed relied more on duration in vowel recognition than the native English speakers did. After the training, however, the Finns were able to use the spectral cues of the vowels more reliably than before. Accordingly, the MMN brain responses revealed that the training had enhanced the Finns’ ability to preattentively process the spectral cues of the English vowels. This suggests that as a result of training, plastic changes had occurred in the weighting of phonetic cues at early processing stages in the cortex.
from the Journal of Cognitive Neuroscience
Preventive screening for early readers: Predictive validity of the Dynamic Indicators of Basic Early Literacy Skills (DIBELS)
Current empirical evidence indicates poor learning trajectories for students with early literacy skill deficits. As such, reliable and valid detection of at-risk students through regular screening and progress monitoring is imperative. This study investigated the predictive validity of scores on the Dynamic Indicators of Basic Early Literacy Skills (DIBELS). Logistic regression analyses were used to test the utility of the DIBELS first grade indicators for predicting reading proficiency on TerraNova California Achievement Test (CAT) Assessment and Pennsylvania System of School Assessment (PSSA) in second and third grade, respectively. Results suggest that students’ first grade Oral Reading Fluency (ORF) DIBELS risk category scores were the only significant predictor of future TerraNova and PSSA reading proficiency. Although the current data present encouraging results for the predictive validity of ORF as a screening tool for early readers, further investigations of the utility of the remaining indicators (Letter Naming Fluency, Nonsense Word Fluency, and Phonemic Segmentation Fluency) are warranted. © 2009 Wiley Periodicals, Inc.
Comprehension of Speeded Discourse by Younger and Older Listeners
Researchers have argued that older adults are more adversely affected by speeding speech than are younger adults. However, the age effects usually occur when (1) the speech materials are artificially speeded to rates well above those that occur in natural speech; (2) the speeding method introduces distortions that tax the older adult’s auditory processes; and (3) the speech materials are simple sentences or very short passages. This study evaluated whether older adults are disadvantaged when listening to extended discourse (10- to 15-min lectures) speeded to a rate near to the limit of normally encountered fast speech (240 words/min) with a minimum of acoustic distortion. Perceptual difficulty was further manipulated by presenting stimuli in either quiet or with a 12-talker background babble. Younger and older adults had more difficulty recalling the details of the discourse and integrating their contexts when stimuli were presented at faster rates and in higher levels of background noise. Although each of these manipulations were found to cause large differences in performance, the age groups were generally found to perform analogously in most conditions. Potentially the availability of semantically rich materials, and the extended durations of the passages, allowed the older adults an opportunity to adjust to the faster speech rates and maintain performance levels similar to younger adults.
Paediatric speech intelligibility (PSI) in normal hearing children with history of recurrent otitis media with effusion (OME)
Otitis media with effusion (OME) is one of the most common disorders in childhood. Several investigators have reported central auditory processing disorders in children with recurrent attacks of OME. The aim was to study PSI in children with normal hearing and those with a history of recurrent OME. The study group consisted of 40 children, age range 5-8 years, with a previous history of three to five attacks of otitis media with effusion (OME). The average length of OME was 8.3 weeks/attack. The study group was divided into two equal subgroups, A and B; subgroup A had recently recovered from OME while subgroup B had recovered from OME at an earlier time. The control group consisted of 20 children with normal hearing. The control and study groups had matched age and gender distribution. A t-test was carried out to compare the different listening conditions of the PSI test in the control and the two study subgroups (CCM 0, CCM -20, ICM 0 and ICM+4). Non-statistically significant differences were found in all listening conditions when comparing the control group and subgroup B. Comparing the results of PSI testing of subgroup A to either control group or subgroup B, there were statistically high differences in all of the different testing conditions (p<0.01). Recurrent attacks of OME during the early years of life affect figure-ground ability as indicated by the significantly reduced PSI scores. However, this affection is reversed within a few months of recovery from OME.
Acquisition of gender agreement in Lithuanian: Exploring the effect of diminutive usage in an elicited production task
This study examines Lithuanian children’s acquisition of gender agreement using an elicited production task. Lithuanian is a richly inflected Baltic language, with two genders and seven cases. Younger (N=24, mean 3 ; 1, 2 ; 5–3 ; 8) and older (N=24, mean 6 ; 3, 5 ; 6–6 ; 9) children were shown pictures of animals and asked to describe them after hearing the animal’s name. Animal names differed with respect to familiarity (novel vs. familiar), derivational status (diminutive vs. simplex) and gender (masculine vs. feminine). Analyses of gender-agreement errors based on adjective and pronoun usage indicated that younger children made more errors than older children, with errors more prevalent for novel animal names. For novel animals, and for feminine nouns, children produced fewer errors with nouns introduced in diminutive form. These results complement findings from several Slavic languages (Russian, Serbian and Polish) that diminutives constitute a salient cluster of word forms that may provide an entry point for the child’s acquisition of noun morphology.
from the Journal of Child Language
Direct and indirect cues to knowledge states during word learning
The present study investigated three-year-olds’ sensitivity to direct and indirect cues to others’ knowledge states for word learning purposes. Children were given either direct, physical cues to knowledge or indirect, verbal cues to knowledge. Preschoolers revealed a better ability to learn words from a speaker following direct, physical cues to their knowledge state. Implications for children’s emerging pragmatic competence are discussed.
from the Journal of Child Language
Integration of communicative partner’s visual perspective in patterns of referential requests
How do Turkish children differ from adults in sensitivity to the commonality of their partner’s perspective with their own in producing referential language? Fifteen five- to six-year-olds, 15 nine- to ten-year-olds and 15 adults were asked to tell a confederate to pick up an object across three conditions: the common ground condition, in which two similar objects with one contrastive feature were visible to both the participants and the confederate; the privileged ground condition, in which one of the two similar objects was available only to the participant; and the baseline condition, in which there were no competing objects. Age-related increases were found from preschool ages into adulthood in the production of (a) discriminating adjectives in the common ground trials, and (b) requestive speech acts with verbal constructions, rather than noun-only labels. A follow-up study with preschoolers (N=15) prompted for requestive speech acts, leading to an increase in discriminating adjectives.
from the Journal of Child Language
Liaison acquisition, word segmentation and construction in French: a usage-based account
In the linguistics field, liaison in French is interpreted as an indicator of interactions between the various levels of language organization. The current study examines the same issue while adopting a developmental perspective. Five experiments involving children aged two to six years provide evidence for a developmental scenario which interrelates a number of different issues: the acquisition of phonological alternations, the segmentation of new words, the long-term stabilization of the word form in the lexicon and the formation of item-based constructions. According to this scenario, children favour the presence of initial CV syllables when segmenting stored chunks of speech of the type word1-liaison-word2 (les arbres ‘the trees’ is segmented as /le/+/zarbr/). They cope with the variation of the liaison in the input by memorizing multiple exemplars of the same word2 (/zarbr/, /narbr/). They learn the correct relations between the word1s and the word2 exemplars through exposure to the well-formed sequence (un+/narbr/, deux+/zarbr/). They generalize the relation between a word1 and a class of word2 exemplars beginning with a specific liaison consonant by integrating this information into an item-based schema (e.g. un+/nX/, deux+/zX/). This model is based on the idea that the segmentation of new words and the development of syntactic schemas are two aspects of the same process.
from the Journal of Child Language
Mean Length of Utterance before words and grammar: Longitudinal trends and developmental implications of infant vocalizations
This study measured longitudinal change in six parameters of infant utterances (i.e. number of sounds, CV syllables, supraglottal consonants, and repetitions per utterance, temporal duration, and seconds per sound), investigated previously unexplored characteristics of repetition (i.e. number of vowel and CV syllable repetitions per utterance) and analyzed change in vocalizations in relation to age and developmental milestones using multilevel models. Infants (N=18) were videotaped bimonthly during naturalistic and semi-structured activities between 0 ; 3 and the onset of word use (M=11·8 months). Results showed that infant utterances changed in predictable ways both in relation to age and in relation to language milestones (i.e. reduplicated babble onset, word comprehension and word production). Looking at change in relation to the milestones of language development led to new views of babbling, the transition from babbling to first words, and processes that may underlie these transitions.
from the Journal of Child Language
