The Influence of Auditory Acuity on Acoustic Variability and the Use of Motor Equivalence During Adaptation to a Perturbation
Conclusion: These results provide support for the mutual interdependence of speech perception and production.
Previous research has suggested that the left anterior insula, specifically the superior precentral gyrus of the insula (SPGI), is a critical brain region for the coordination of complex articulatory movements. However, previous studies have not determined which articulatory factors are specifically dependent on this brain region. In the current study, 33 left hemisphere stroke patients with varying degrees of speech impairment were asked to perform multiple repetitions of single words that varied along three separate dimensions: number of syllables, degree of articulatory travel (i.e., change between places of articulation for consonants), and presence/absence of an initial consonant cluster. The role of the SPGI in performance across the three conditions was determined using voxel-based lesion symptom mapping (VLSM), a statistical approach to lesion analysis that does not require separating patients based on lesion site or symptom profile. Rather, continuous performance data are entered, along with lesions reconstructed in normalized space. Based on preliminary analyses, there was adequate power to detect differences in the SPGI, which was the focus of our predictions. We found that the SPGI was critical for performance on the articulation task across all three conditions, namely, when words were multi-syllabic, required a high degree of travel, or involved an initial consonant cluster. As a control, we also generated a VLSM map for articulation of words with minimal articulatory complexity (i.e., single-syllable words with no initial cluster and a minimal change in place of articulation). In this case, the SPGI was not implicated. The current results suggest that the left SPGI is a critical area for intra- and inter-syllabic coordination of complex articulatory movements, prior to end-stage execution of speech commands.
The identification of the first gene involved in a speech-language disorder was made possible through the study of a British multi-generational family (the “KE family”) in whom half the members have an inherited speech-language disorder caused by a FOXP2 mutation. Neuroimaging investigations in the affected members of the KE family have revealed structural and functional abnormalities in a wide cortical-subcortical network. Functional imaging studies have confirmed dysfunction of this network by revealing abnormal activation in several areas including Broca’s area and the putamen during language-related tasks, such as word repetition and generation. Repeating nonsense words is particularly challenging for the affected members of the family, as well as in other individuals suffering from idiopathic developmental specific language impairments; yet, thus far the neural correlates of the nonword repetition task have not been examined in individuals with developmental speech and language disorders. Here, four affected members of the KE family and four unrelated age-matched healthy participants repeated nonsense words aloud during functional MRI scanning. Relative to control participants, repetition in the affected members was severely impaired, and brain activation was significantly reduced in the premotor, supplementary and primary motor cortices, as well as in the cerebellum and basal ganglia. We suggest that nonword repetition is the optimal endophenotype for FOXP2 disruption in humans because this task recruits brain regions involved in the imitation and vocal learning of novel sequences of speech sounds.
Conclusion: Understanding the phonological characteristics of the native language can help clinicians recognize speech patterns in the second language associated with transfer. Once these differences are understood, patterns associated with a residual SSD can be identified. Supplementing a relational speech analysis with measures of speech motor control and phonological awareness can provide a more comprehensive understanding of a client’s strengths and needs.
Conclusions: The present study makes a significant theoretical contribution to the literature as the first study, to our knowledge, that has tested the hypothesis that weaknesses in representation-related phonological processing may underlie the difficulties in phonological awareness and reading that are demonstrated by children with SSDs.
Conclusions: CHAUSA produces high-FR, high-spatial-quality ultrasound images, which are head corrected to 1 mm. The method reveals tongue dorsum retraction during the posterior release of the alveolar click and tongue tip recoil following the anterior release of the alveolar click, both of which were previously undetectable. CHAUSA visualizes most of the tongue in studies of dynamic consonants with a major reduction in field problems, opening up important areas of speech research.
Lateralization of Speech Production Starts in Sensory Cortices—A Possible Sensory Origin of Cerebral Left Dominance for Speech
Speech production is a left-lateralized brain function, which could arise from a left dominance either in speech executive or sensory processes or both. Using functional magnetic resonance imaging in healthy subjects, we show that sensory cortices already lateralize when speaking is intended, while the frontal cortex only lateralizes when speech is acted out. The sequence of lateralization, first temporal then frontal lateralization, suggests that the functional lateralization of the auditory cortex could drive hemispheric specialization for speech production.
from Cerebral Cortex
This article offers an overview of changes to speech and voice that arise in PD and the impact these underlying changes have on speech naturalness, intelligibility and participation in social life. Assessment and treatment are not a focus, but lessons for these areas are drawn from the description of the nature of overall changes.
What models of verbal working memory can learn from phonological theory: Decomposing the phonological similarity effect
Despite developments in phonology over the last few decades, models of verbal working memory make reference to phoneme-sized phonological units, rather than to the features of which they are composed. This study investigates the influence on short-term retention of such features by comparing the serial recall of lists of syllables with varying types and levels of similarity in their onset consonants. Lists are (a) dissimilar (/fa–na–ga/) (b) acoustically similar (/pa-ta-ka/) or (c) articulatorily similar (/da–la–za/). When no overt articulation is required, we find no decrease in performance for articulatorily similar items as compared to the dissimilar list. However, we are able to show that acoustic similarity clearly impairs recall. It is only when participants recall the lists orally, that performance is impaired for both types of similar lists. These results have implications for accounts of the phonological similarity effect in particular and of verbal working memory in general.
from the Journal of Memory and Language
According to the results of this study the speech and language management must be focused on receptive and expressive language skills and linguistic conceptualization, correct phonetic placement and the modification of hypernasality and nasal emission.
Reliability and Validity of a Computer Mediated Single-Word Intelligibility Test: Preliminary Findings for Children with Repaired Cleft Lip and Palate.
Conclusions: A computerized, single-word intelligibility test was described which appears to be a reliable and valid measure of global speech deficits in children with CLP. Additional development of the test may further facilitate standardized assessment of children with CLP.
from the Cleft Palate-Craniofacial Journal
Conclusions: Our results indicate that variation in language skill in NS is closely related to cognitive, perceptual, and motor factors. It does not appear that specific aspects of language are selectively affected in this syndrome.
This study investigated the extent to which language skills at ages 2 to 4 years could discriminate Hong Kong Chinese poor from adequate readers at age 7. Selected were 41 poor readers (age M = 87.6 months) and 41 adequate readers (age M = 88.3 months). The two groups were matched on age, parents’ education levels, and nonverbal intelligence. The following language tasks were tested at different ages: vocabulary checklist and Cantonese articulation test at age 2; nonword repetition, Cantonese articulation, and receptive grammar at age 3; and nonword repetition, receptive grammar, sentence imitation, and story comprehension at age 4. Significant differences between the poor and adequate readers were found in the age 2 vocabulary knowledge, age 3 Cantonese articulation, and age 4 receptive grammar skill, sentence imitation, and story comprehension. Among these measures, sentence imitation showed the greatest power in discriminating poor and adequate readers.
from the Journal of Learning Disabilities
The contribution(s) of the insula to speech production: a review of the clinical and functional imaging literature
Skilled spoken language production requires fast and accurate coordination of up to 100 muscles. A long-standing concept—tracing ultimately back to Paul Broca—assumes posterior parts of the inferior frontal gyrus to support the orchestration of the respective movement sequences prior to innervation of the vocal tract. At variance with this tradition, the insula has more recently been declared the relevant “region for coordinating speech articulation”, based upon clinico-neuroradiological correlation studies. However, these findings have been criticized on methodological grounds. A survey of the clinical literature (cerebrovascular disorders, brain tumours, stimulation mapping) yields a still inconclusive picture. By contrast, functional imaging studies report more consistently hemodynamic insular responses in association with motor aspects of spoken language. Most noteworthy, a relatively small area at the junction of insular and opercular cortex was found sensitive to the phonetic-linguistic structure of verbal utterances, a strong argument for its engagement in articulatory control processes. Nevertheless, intrasylvian hemodynamic activation does not appear restricted to articulatory processes and might also be engaged in the adjustment of the autonomic system to ventilatory needs during speech production: Whereas the posterior insula could be involved in the cortical representation of respiration-related metabolic (interoceptive) states, the more rostral components, acting upon autonomic functions, might serve as a corollary pathway to “voluntary control of breathing” bound to corticospinal and -bulbar fiber tracts. For example, the insula could participate in the implementation of task-specific autonomic settings such as the maintenance of a state of relative hyperventilation during speech production.
The results provide some preliminary evidence of reduced anticipatory lingual movement in AOS, and have demonstrated that this can have a significant impact on absolute speech timing. However, measures of relative timing were suggestive of either unimpaired or more extensive coarticulation. Additional research is required to resolve this issue.