Blog Archives

Neural bases of childhood speech disorders: lateralization and plasticity for speech functions during development

Current models of speech production in adults emphasize the crucial role played by the left perisylvian cortex, primary and pre-motor cortices, the basal ganglia, and the cerebellum for normal speech production. Whether similar brain-behaviour relationships and leftward cortical dominance are found in childhood remains unclear. Here we reviewed recent evidence linking motor speech disorders (apraxia of speech and dysarthria) and brain abnormalities in children and adolescents with developmental, progressive, or childhood-acquired conditions. We found no evidence that unilateral damage can result in apraxia of speech, or that left hemisphere lesions are more likely to result in dysarthria than lesion to the right. The few studies reporting on childhood apraxia of speech converged towards morphological, structural, metabolic or epileptic anomalies affecting the basal ganglia, perisylvian and rolandic cortices bilaterally. Persistent dysarthria, similarly, was commonly reported in individuals with syndromes and conditions affecting these same structures bilaterally. In conclusion, for the first time we provide evidence that longterm and severe childhood speech disorders result predominantly from bilateral disruption of the neural networks involved in speech production.

from Neuroscience and Biobehavioral Reviews

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Hearing speech in music

The masking effect of a piano composition, played at different speeds and in different octaves, on speech-perception thresholds was investigated in 15 normal-hearing and 14 moderately-hearing-impaired subjects. Running speech (just follow conversation, JFC) testing and use of hearing aids increased the everyday validity of the findings. A comparison was made with standard audiometric noises [International Collegium of Rehabilitative Audiology (ICRA) noise and speech spectrum-filtered noise (SPN)]. All masking sounds, music or noise, were presented at the same equivalent sound level (50 dBA). The results showed a significant effect of piano performance speed and octave (P<.01). Low octave and fast tempo had the largest effect; and high octave and slow tempo, the smallest. Music had a lower masking effect than did ICRA noise with two or six speakers at normal vocal effort (P<.01) and SPN (P<.05). Subjects with hearing loss had higher masked thresholds than the normal-hearing subjects (P<.01), but there were smaller differences between masking conditions (P<.01). It is pointed out that music offers an interesting opportunity for studying masking under realistic conditions, where spectral and temporal features can be varied independently. The results have implications for composing music with vocal parts, designing acoustic environments and creating a balance between speech perception and privacy in social settings.

from Noise & Health

Speech-associated labiomandibular movement in Mandarin-speaking children with quadriplegic cerebral palsy: A kinematic study

The purpose of this study was to investigate the speech-associated labiomandibular movement during articulation production in Mandarin-speaking children with spastic quadriplegic (SQ) cerebral palsy (CP). Twelve children with SQ CP (aged 7–11 years) and 12 age-matched healthy children as controls were enrolled for the study. All children underwent analysis of percentage of consonants correct (PCC) and kinematic analysis of speech tasks using the Vicon Motion 370 system. Kinematic parameters included utterance duration, displacement and velocity of the lip and jaw, coefficient of variation (CV) of lip utterance duration, and spatial and temporal coupling of labiomandibular movement of speech produced in mono-syllable (MS) and poly-syllable (PS) tasks. Children with CP showed lower temporal coupling (MS, p = 0.015; PS, p = 0.007), but not spatial coupling, of labiomandibular movement than healthy children. Children with CP had greater CVs (MS, p = 0.003; PS, p = 0.010) and the peak opening displacement and velocity of lower lip and jaw (p < 0.05) and lower PCC (p < 0.001) than healthy children. Children with SQ CP displayed labiomandibular coupling movement impairment, especially in the aspect of temporal coupling. These children also had high temporal oromotor variability and needed to make more effort to coordinate the labiomandibular movement for speech production.

from Research in Developmental Disabilities

The organization of narrative discourse in Lewy body spectrum disorder

Narrative discourse is an essential component of day-to-day communication, but little is known about narrative in Lewy body spectrum disorder (LBSD), including Parkinson’s disease (PD), Parkinson’s disease with dementia (PDD), and dementia with Lewy bodies (DLB). We performed a detailed analysis of a semi-structured speech sample in 32 non-aphasic patients with LBSD, and we related their narrative impairments to gray matter (GM) atrophy using voxel-based morphometry. We found that patients with PDD and DLB have significant difficulty organizing their narrative speech. This was correlated with deficits on measures of executive functioning and speech fluency. Regression analyses associated this deficit with reduced cortical volume in inferior frontal and anterior cingulate regions. These findings are consistent with a model of narrative discourse that includes executive as well as language components and with an impairment of the organizational component of narrative discourse in patients with PDD and DLB.

from Brain and Language

Conflict resolution strategies in children with normal language development: cooperation or individualism?

CONCLUSION: At 7 and 8 years of age, children with normal language development frequently use unilateral and cooperative strategies to solve problems.

from Revista de Sociedade Brasileira de Fonoaudiologia

Longitudinal pragmatic profile of a child with auditory neuropathy spectrum disorder

Human communication depends mostly on the conversion of ideas into language, involving the interaction among all its components – phonological, semantic, syntactic and pragmatic. Pragmatics studies the relationship between the social meaning of language and its semantic content, expressed by the communicative act itself. Auditory neuropathy spectrum disorder generates a dyssynchrony in nerve conduction, contributing to an impairment in speech perception. In hearing impaired children the language acquisition and development process can be stimulated with intervention. The aim of this study was to present a longitudinal follow-up of the use of pragmatic communication abilities by a child with auditory neuropathy spectrum disorder. The child received speech-language pathology therapy during three years in the Educational Audiology area. Video recordings of spontaneous conversation were made in the beginning of each year. These recordings were transcribed and analyzed according to the verbal communicative abilities protocol. In the initial recording, the most frequent ability presented by the child was the direct response; however these were extended to more complex responses during the intervention. In the last recording the child proposes new topics of discourse, produce narratives and arguments. The emergence of more sophisticated communication skills is justified by the language development, which benefits from language therapy with hearing impaired children. This suggests that, for the case study described, speech-language pathology therapy contributed to the improvement of pragmatic communication abilities.

from Revista de Sociedade Brasileira de Fonoaudiologia

Weighting of cues for fricative place of articulation perception by children wearing cochlear implants

Conclusions: Children wearing a cochlear implant use similar cue-weighting strategies as normal listeners (i.e. all apply more weight to the frication noise than to the transition cue), but may have limitations in processing formant transitions and in cue interaction.

from the International Journal of Audiology

Stuttering Treatment Control Using P300 Event-Related Potentials

Positron Emission Tomography studies during speech have indicated a failure to show the normal activation of auditory cortical areas in stuttering individuals. In the present study, P300 event-related potentials were used to investigate possible effects of behavioral treatment on the pattern of signal amplitude and latency between waves. In order to compare variations in P300 measurements, a control group paired by age and gender to the group of stutterers, was included in the study. Findings suggest that the group of stutterers presented a significant decrease in stuttering severity after the fluency treatment program. Regarding P300 measurements, stutterers and their controls presented results within normal limits in all testing situations and no significant statistical variations between pre and post treatment testing. When comparing individual results between the testing situations, stutterers presented a higher average decrease in wave latency for the right ear following treatment. The results are discussed in light of previous P300 event-related potentials and functional imaging studies with stuttering adults

from Journal of Fluency Disorders

A brief review on the use of functional near-infrared spectroscopy (fNIRS) for language imaging studies in human newborns and adults

Upon stimulation, real time maps of cortical hemodynamic responses can be obtained by non-invasive functional near-infrared spectroscopy (fNIRS) which measures changes in oxygenated and deoxygenated hemoglobin after positioning multiple sources and detectors over the human scalp. The current commercially available transportable fNIRS systems have a time resolution of 1–10 Hz, a depth sensitivity of about 1.5 cm, and a spatial resolution of about 1 cm. The goal of this brief review is to report infants, children and adults fNIRS language studies. Since 1998, 60 studies have been published on cortical activation in the brain’s classic language areas in children/adults as well as newborns using fNIRS instrumentations of different complexity. In addition, the basic principles of fNIRS including features, strengths, advantages, and limitations are summarized in terms that can be understood even by non specialists. Future prospects of fNIRS in the field of language processing imaging are highlighted.

from Brain and Language

Speed-difficulty trade-off in speech: Chinese versus English

This study continues the investigation of the previously described speed-difficulty trade-off in picture description tasks. In particular, we tested a hypothesis that the Mandarin Chinese and American English are similar in showing logarithmic dependences between speech time and index of difficulty (ID), while they differ significantly in the amount of time needed to describe simple pictures, this difference increases for more complex pictures, and it is associated with a proportional difference in the number of syllables used. Subjects (eight Chinese speakers and eight English speakers) were tested in pairs. One subject (the Speaker) described simple pictures, while the other subject (the Performer) tried to reproduce the pictures based on the verbal description as quickly as possible with a set of objects. The Chinese speakers initiated speech production significantly faster than the English speakers. Speech time scaled linearly with ln(ID) in all subjects, but the regression coefficient was significantly higher in the English speakers as compared with the Chinese speakers. The number of errors was somewhat lower in the Chinese participants (not significantly). The Chinese pairs also showed a shorter delay between the initiation of speech and initiation of action by the Performer, shorter movement time by the Performer, and shorter overall performance time. The number of syllables scaled with ID, and the Chinese speakers used significantly smaller numbers of syllables. Speech rate was comparable between the two groups, about 3 syllables/s; it dropped for more complex pictures (higher ID). When asked to reproduce the same pictures without speaking, movement time scaled linearly with ln(ID); the Chinese performers were slower than the English performers. We conclude that natural languages show a speed-difficulty trade-off similar to Fitts’ law; the trade-offs in movement and speech production are likely to originate at a cognitive level. The time advantage of the Chinese participants originates not from similarity of the simple pictures and Chinese written characters and not from more sloppy performance. It is linked to using fewer syllables to transmit the same information. We suggest that natural languages may differ by informational density defined as the amount of information transmitted by a given number of syllables.

from Experimental Brain Research

Mandarin Chinese speech recognition by pediatric cochlear implant users

Consistent with previous studies’ findings, early implantation provided a significant advantage for profoundly deaf children. Performance for both groups was generally quite good for the relatively difficult materials and tasks, suggesting that open-set word and sentence recognition may be useful in evaluating speech performance with older pediatric CI users. Differences in disyllable recognition between Groups 1 and 2 may reflect differences in adaptation to electric stimulation. The Group 1 subjects developed speech patterns exclusively via electric stimulation, while the Group 2 subjects adapted to electric stimulation relative to previous acoustic patterns.

from the International Journal of Pediatric Otorhinolaryngology

Expressiveness on the radio: Speech-Language Pathology practices in question

CONCLUSION: The term oral expressiveness is not generally used by the subjects interviewed, due to the fact that its concept is new to them. The term comprises the conveyance of emotions and intention by the speaker. The following aspects were considered to interfere on oral expressiveness: listeners’ judgment; adequacy of the speech to the context; style of the radio station; and textual content of the message, evidencing the dynamics between subjective and social. More theoretical studies in Linguistics may subsidize less conceptually diverse practices when considering speech-language interventions.

from Revista de Sociedade Brasileira de Fonoaudiologia

Developing professional learning for staff working with children with speech, language and communication needs combined with moderate-to-severe learning difficulties

This article presents research undertaken as part of a PhD by Carolyn Anderson who is a senior lecturer on the BSc (Hons) in Speech and Language Pathology at the University of Strathclyde. The study explores the professional learning experiences of 49 teachers working in eight schools and units for children with additional support needs in Scotland. In particular, she examines the professional learning experiences of teachers working with children with speech, language and communication needs (SLCN) combined with moderate-to-severe learning difficulties. While the teachers under study predominantly engaged with informal professional learning, she observes that they often expressed a lack of confidence in this form of professional development, tending to value formal learning regardless of impact. In response she raises a number of important questions about the role of Initial Teacher and Postgraduate Education and the ways in which schools understand reflective practice.

from the British Journal of Special Education

Observation-execution matching and action inhibition in human primary motor cortex during viewing of speech-related lip movements or listening to speech

One influential theory posits that language has evolved from gestural communication through observation-execution matching processes in the mirror neuron system (MNS). This theory predicts that observation of speech-related lip movements or even listening to speech would result in effector and task specific increase of the excitability of the corresponding motor representations in the primary motor cortex (M1), since actual movement execution is known be effector and task specific. In addition, effector and task specific inhibitory control mechanisms should be important to prevent overt motor activation during observation of speech-related lip movements or listening to speech. We tested these predictions by applying focal transcranial magnetic stimulation to the left M1 of 12 healthy right-handed volunteers and measuring motor evoked potentials (MEPs) and short-interval intracortical inhibition (SICI) in a lip muscle, the right orbicularis oris (OO), versus a hand muscle, the right first dorsal interosseus (FDI). We found that MEP and SICI increased only in the OO but not in the FDI during viewing of speech-related lip movements or listening to speech. These changes were highly task specific because they were absent when lip movements non-related to speech were viewed. Finally, the increase in MEP amplitude in the OO correlated inversely with accuracy of speech perception, i.e. the MEP increase was directly related to task difficulty. The MEP findings support the notion that observation-execution matching is an operating process in the putative human MNS that might have been fundamental for evolution of language. Furthermore, the SICI findings provide evidence that inhibitory mechanisms are recruited to prevent unwanted overt motor activation during action observation.

from Neuropsychologia

Developing professional learning for staff working with children with speech, language and communication needs combined with moderate-to-severe learning difficulties

This article presents research undertaken as part of a PhD by Carolyn Anderson who is a senior lecturer on the BSc (Hons) in Speech and Language Pathology at the University of Strathclyde. The study explores the professional learning experiences of 49 teachers working in eight schools and units for children with additional support needs in Scotland. In particular, she examines the professional learning experiences of teachers working with children with speech, language and communication needs (SLCN) combined with moderate-to-severe learning difficulties. While the teachers under study predominantly engaged with informal professional learning, she observes that they often expressed a lack of confidence in this form of professional development, tending to value formal learning regardless of impact. In response she raises a number of important questions about the role of Initial Teacher and Postgraduate Education and the ways in which schools understand reflective practice.

from the British Journal of Special Education