The effects of Thalamic Deep Brain Stimulation on speech dynamics in patients with Essential Tremor: An articulographic study.

Acoustic studies have revealed that patients with Essential Tremor treated with thalamic Deep Brain Stimulation (DBS) may suffer from speech deterioration in terms of imprecise oral articulation and reduced voicing control. Based on the acoustic signal one cannot infer, however, whether this deterioration is due to a general slowing down of the speech motor system (e.g., a target undershoot of a desired articulatory goal resulting from being too slow) or disturbed coordination (e.g., a target undershoot caused by problems with the relative phasing of articulatory movements). To elucidate this issue further, we here investigated both acoustics and articulatory patterns of the labial and lingual system using Electromagnetic Articulography (EMA) in twelve Essential Tremor patients treated with thalamic DBS and twelve age- and sex-matched controls. By comparing patients with activated (DBS-ON) and inactivated stimulation (DBS-OFF) with control speakers, we show that critical changes in speech dynamics occur on two levels: With inactivated stimulation (DBS-OFF), patients showed coordination problems of the labial and lingual system in terms of articulatory imprecision and slowness. These effects of articulatory discoordination worsened under activated stimulation, accompanied by an additional overall slowing down of the speech motor system. This leads to a poor performance of syllables on the acoustic surface, reflecting an aggravation either of pre-existing cerebellar deficits and/or the affection of the upper motor fibers of the internal capsule.

Efficacy of Electropalatography for Treating Misarticulation of /r/.

PURPOSE: The purpose of the present study was to document the efficacy of electropalatography (EPG) for the treatment of rhotic errors in school-age children. Despite a growing body of literature using EPG for the treatment of speech sound errors, there is little systematic evidence about the relative efficacy of EPG for rhotic errors. METHOD: Participants were 5 English-speaking children aged 6;10 to 9;10, who produced /r/ at the word level with < 30% accuracy but otherwise showed typical speech, language, and hearing abilities. Therapy was delivered in twice-weekly 30-min sessions for 8 weeks. RESULTS: Four out of 5 participants were successful in achieving perceptually and acoustically accurate /r/ productions during within-treatment trials. Two participants demonstrated generalization of /r/ productions to nontreated targets, per blinded listener ratings. CONCLUSIONS: The present findings support the hypothesis that EPG can improve production accuracy in some children with rhotic errors. However, the utility of EPG is likely to remain variable across individuals. For rhotics, EPG training emphasizes one possible tongue configuration consistent with accurate rhotic production (lateral tongue contact). Although some speakers respond well to this cue, the narrow focus may limit lingual exploration of other acceptable tongue shapes known to facilitate rhotic productions.

Pitch discrimination associated with phonological awareness: Evidence from congenital amusia.

Research suggests that musical skills are associated with phonological abilities. To further investigate this association, we examined whether phonological impairments are evident in individuals with poor music abilities. Twenty individuals with congenital amusia and 20 matched controls were assessed on a pure-tone pitch discrimination task, a rhythm discrimination task, and four phonological tests. Amusic participants showed deficits in discriminating pitch and discriminating rhythmic patterns that involve a regular beat. At a group level, these individuals performed similarly to controls on all phonological tests. However, eight amusics with severe pitch impairment, as identified by the pitch discrimination task, exhibited significantly worse performance than all other participants in phonological awareness. A hierarchical regression analysis indicated that pitch discrimination thresholds predicted phonological awareness beyond that predicted by phonological short-term memory and rhythm discrimination. In contrast, our rhythm discrimination task did not predict phonological awareness beyond that predicted by pitch discrimination thresholds. These findings suggest that accurate pitch discrimination is critical for phonological processing. We propose that deficits in early-stage pitch discrimination may be associated with impaired phonological awareness and we discuss the shared role of pitch discrimination for processing music and speech.

Perceptual, durational and tongue displacement measures following articulation therapy for rhotic sound errors.

Outcomes of articulation therapy for rhotic errors are usually assessed perceptually. However, our understanding of associated changes of tongue movement is limited. This study described perceptual, durational and tongue displacement changes over 10 sessions of articulation therapy for /ɹ/ in six children. Four of the participants also received ultrasound biofeedback of their tongue shape. Speech and tongue movement were recorded pre-therapy, after 5 sessions, in the final session and at a one month follow-up. Perceptually, listeners perceived improvement and classified more productions as /ɹ/ in the final and follow-up assessments. The durations of VɹV syllables at the midway point of the therapy were longer. Cumulative tongue displacement increased in the final session. The average standard deviation was significantly higher in the middle and final assessments. The duration and tongue displacement measures illustrated how articulation therapy affected tongue movement and may be useful for outcomes research about articulation therapy.

Retroflex versus bunched in treatment for rhotic misarticulation: evidence from ultrasound biofeedback intervention.

PURPOSE: To document the efficacy of ultrasound biofeedback treatment for misarticulation of the North American English rhotic in children. Because of limited progress in the first cohort, a series of two closely related studies was conducted in place of a single study. The studies differed primarily in the nature of tongue-shape targets (e.g., retroflex, bunched) cued during treatment. METHOD: Eight participants received 8 weeks of individual ultrasound biofeedback treatment targeting rhotics. In Study 1, all 4 participants were cued to match a bunched tongue-shape target. In Study 2, participants received individualized cues aimed at eliciting the tongue shape most facilitative of perceptually correct rhotics. RESULTS: Participants in Study 1 showed only minimal treatment effects. In Study 2, all participants demonstrated improved production of rhotics in untreated words produced without biofeedback, with large to very large effect sizes. CONCLUSIONS: The results of Study 2 indicate that with proper parameters of treatment, ultrasound biofeedback can be a highly effective intervention for children with persistent rhotic errors. In addition, qualitative comparison of Studies 1 and 2 suggests that treatment for the North American English rhotic should include opportunities to explore different tongue shapes, to find the most facilitative variant for each individual speaker.

Organización de redes neuronales en el cerebro del síndrome de Down / No disponible

Todas las funciones cerebrales -sensoriales, motoras, cognitivas, conductuales- son el resultado de la actividad de las neuronas. Pero éstas no funcionan de manera aislada sino que conforman intrincadas redes y circuitos perfectamente establecidos, gracias a los cuales se van originando los elementos que sustancian la percepción, la conciencia, el conocimiento, etc. Cuanto más compleja sea la función a desarrollar, más complicada y extensa será la red neuronal responsable de poner en marcha y mantener dicha función. El número de unidades neuronales y de sus conexiones está reducido en ciertas zonas del cerebro del síndrome de Down, por lo que las redes y circuitos que conforman tendrán una menor extensión y una menor capacidad organizativa, lo que constituye la base del decremento en la expresión de determinadas habilidades. Pero ¿es posible que en el síndrome de Down la reducción de la actividad de una zona cerebral afectada pueda ser sustituida o compensada por la actividad de otra, menos o nada afectada?

No disponible

Perceptual learning of acoustic noise by individuals with dyslexia.

PURPOSE: A phonological deficit is thought to affect most individuals with developmental dyslexia. The present study addresses whether the phonological deficit is caused by difficulties with perceptual learning of fine acoustic details. METHOD: A demanding test of nonverbal auditory memory, "noise learning," was administered to both adults with dyslexia and control adult participants. On each trial, listeners had to decide whether a stimulus was a 1-s noise token or 2 abutting presentations of the same 0.5-s noise token (repeated noise). Without the listener's knowledge, the exact same noise tokens were presented over many trials. An improved ability to perform the task for such "reference" noises reflects learning of their acoustic details. RESULTS: Listeners with dyslexia did not differ from controls in any aspect of the task, qualitatively or quantitatively. They required the same amount of training to achieve discrimination of repeated from nonrepeated noises, and they learned the reference noises as often and as rapidly as the control group. However, they did show all the hallmarks of dyslexia, including a well-characterized phonological deficit. CONCLUSION: The data did not support the hypothesis that deficits in basic auditory processing or nonverbal learning and memory are the cause of the phonological deficit in dyslexia.

Electrophysiological indices of phonological impairments in dyslexia.

PURPOSE: A range of studies have shown difficulties in perceiving acoustic and phonetic information in dyslexia; however, much less is known about how such difficulties relate to the perception of individual words. The authors present data from event-related potentials (ERPs) examining the hypothesis that children with dyslexia have difficulties with processing phonemic information within spoken words compared to age-matched readers with typical development. METHOD: The authors monitored ERPs to auditory words during a simple picture-word matching task. The key manipulation was the inclusion of both matching stimuli and three types of mismatches (cohort, CONE-comb; rhyme, CONE-bone; and unrelated, CONE-fox). RESULTS: Children with dyslexia showed atypical N400 ERP waveforms to both types of phonological mismatches, but not to phonologically unrelated mismatches, reflecting a relative insensitivity to phonological overlap among auditory words. CONCLUSION: The data suggest that children with dyslexia have impairments in integrating phonological information into word-level representations. The results suggest that speech perception difficulties in dyslexia might have consequences for processing auditory words.

Functional maturity of brain structures in children aged 7-8 with differing levels of speech development.

First graders (aged 7-8) in a public elementary school served as subjects for this study. The structural components of their speech were analyzed to determine speech maturity level; total EEG activity was analyzed to assess the functional maturity of brain structures. Results showed that children with levels of speech below the age norm exhibited abnormal EEG patterns suggesting immaturity of the cerebral cortex and fronto-thalamic regulatory system, as well as impairments in the functioning of the mesodiencephalic structures and nonspecific activation systems. Abnormalities in the functioning of brain regulatory systems and the presence of local abnormalities in EEG activity of deep origin are important factors in determining the severity of functional speech impairments.

Changes to articulatory kinematics in response to loudness cues in individuals with Parkinson's disease.

PURPOSE: Individuals with Parkinson's disease (PD) exhibit differences in displacement and velocity of the articulators as compared with older adults. The purpose of the current study was to examine effects of 3 loudness cues on articulatory movement patterns in individuals with PD. METHOD: Nine individuals diagnosed with idiopathic PD and 9 age- and sex-matched healthy controls produced sentences in 4 conditions: (a) comfortable loudness, (b) targeting 10 dB above comfortable, (c) twice as loud as comfortable, and (d) in background noise. Lip and jaw kinematics and acoustic measurements were obtained. RESULTS: Both groups significantly increased sound pressure level (SPL) in the loud conditions as compared with the comfortable condition. For the loud conditions, both groups had the highest SPL in the background noise and the 10 dB conditions, and the lowest SPL in the twice as loud condition. Control participants produced the largest opening displacement in the background noise condition and the smallest opening displacement in the twice as loud condition. Conversely, individuals with PD produced the largest opening displacement in the twice as loud condition and the smallest opening displacement in the background noise condition. CONCLUSIONS: Control participants and individuals with PD responded to cues to increase loudness in different ways. Changes in SPL may explain differences in kinematics for the control participants, but they do not explain such differences for individuals with PD.

Impairments in speech and nonspeech sound categorization in children with dyslexia are driven by temporal processing difficulties.

Auditory processing problems in persons with dyslexia are still subject to debate, and one central issue concerns the specific nature of the deficit. In particular, it is questioned whether the deficit is specific to speech and/or specific to temporal processing. To resolve this issue, a categorical perception identification task was administered in thirteen 11-year old dyslexic readers and 25 matched normal readers using 4 sound continua: (1) a speech contrast exploiting temporal cues (/bA/-/dA/), (2) a speech contrast defined by nontemporal spectral cues (/u/-/y/), (3) a nonspeech temporal contrast (spectrally rotated/bA/-/da/), and (4) a nonspeech nontemporal contrast (spectrally rotated/u/-/y/). Results indicate that children with dyslexia are less consistent in classifying speech and nonspeech sounds on the basis of rapidly changing (i.e., temporal) information whereas they are unimpaired in steady-state speech and nonspeech sounds. The deficit is thus restricted to categorizing sounds on the basis of temporal cues and is independent of the speech status of the stimuli. The finding of a temporal-specific but not speech-specific deficit in children with dyslexia is in line with findings obtained in adults using the same paradigm (Vandermosten et al., 2010, Proceedings of the National Academy of Sciences of the United States of America, 107: 10389-10394). Comparison of the child and adult data indicates that the consistency of categorization considerably improves between late childhood and adulthood, particularly for the continua with temporal cues. Dyslexic and normal readers show a similar developmental progress with the dyslexic readers lagging behind both in late childhood and in adulthood.

A decision-algorithm defining the rehabilitation approach: 'Facial oral tract therapy'.

AIM: The aim of this study was to describe and define the rehabilitation approach: 'Facial Oral Tract Therapy' (F.O.T.T.). METHOD: We defined the content and process of the rehabilitation approach (F.O.T.T.) in a decision-algorithm supported by a manual with supplementary material. The algorithm was developed by a research occupational therapist and an F.O.T.T. senior instructor. We used an inductive approach combining existing knowledge from: F.O.T.T. instructors, therapists trained in using the F.O.T.T. approach, and existing literature. A group of F.O.T.T. instructors and the originator of the treatment approach Mrs. Kay Coombes has given comments to and approved the algorithm. RESULT: The algorithm consist of five flowcharts: 'one assessment' chart guiding the therapist in the examination of the patient and four 'treatment charts', one for each of the four areas of F.O.T.T.: swallowing and eating; oral hygiene; breathing, voice, and speech articulation; facial expression, giving guidance on interventions. The algorithm outlines all important components in the treatment that the therapist should decide to use or not to use in the intervention. The algorithm is supported by a manual with criteria of when to use which components. CONCLUSION: This algorithm is designed to be a practical guideline to therapists using F.O.T.T. in clinical practice and in educational settings. The use of this algorithm may support standardization of F.O.T.T. and thereby promote and maintain the quality in the treatment. This in turn will facilitate research that addresses F.O.T.T. and outcomes.

Electropalatographic therapy for children and young people with Down's syndrome.

Articulation disorders in Down's syndrome (DS) are prevalent and often intractable. Individuals with DS generally prefer visual to auditory methods of learning and may therefore find it beneficial to be given a visual model during speech intervention, such as that provided by electropalatography (EPG). In this study, participants with Down's syndrome, aged 10:1 to 18:9, received 24 individualized therapy sessions using EPG. Simultaneous acoustic and EPG recordings were made pre- and post-intervention during 10 repetitions of a word list containing lingua-palatal consonants. Participants also completed the DEAP phonology sub-test at both time points. Post-treatment, all participants showed qualitative and quantifiable differences in EPG patterns and improvements in DEAP percentage consonants correct. EPG assessment and therapy appears a positive approach for identifying and improving articulatory patterns in children with DS.

Intervention for lateral /s/ using electropalatography (EPG) biofeedback and an intensive motor learning approach: a case report.

BACKGROUND: Visual biofeedback using electropalatography (EPG) has been beneficial in the treatment of some cases of lateral /s/ misarticulation. While EPG intervention is motorically based, studies have not commonly employed a motor learning approach to treatment. Furthermore, treatment success is measured primarily by change to EPG tongue-palate contact patterns and listener ratings conducted by speech-language therapists. Studies have not commonly measured articulatory change without the palate in-situ using acoustic analysis and non-professional listeners. AIMS: To determine if an intensive treatment programme including both visual biofeedback (EPG) and traditional articulation techniques within a motor learning paradigm would result in functional improvement to /s/ articulation in an 11-year-old girl with persistent lateral misarticulation. METHODS & PROCEDURES: Treatment involved 12 sessions of therapist-delivered treatment over 4 weeks followed by a 6-week home programme. Outcomes of the treatment programme were measured primarily using naive listener ratings and acoustic analysis of /s/ spectra. OUTCOMES & RESULTS: Improvements to both the perceptual and spectral characteristics of /s/ articulation occurred following the treatment programme. CONCLUSIONS: The study highlighted the benefit of an intensive approach to intervention incorporating both visual biofeedback and traditional articulation approaches. The inclusion of a 6-week structured home-programme was beneficial and resulted in consolidation of treatment gains.

Speech error elicitation and co-occurrence restrictions in two Ethiopian Semitic languages.

This article reports the results of speech error elicitation experiments investigating the role of two consonant co-occurrence restrictions in the productive grammar of speakers of two Ethiopian Semitic languages, Amharic and Chaha. Higher error rates were found with consonant combinations that violated co-occurrence constraints than with those that had only a high degree of shared phonological similarity or low frequency of co-occurrence. Sequences that violated two constraints had the highest error rates. The results indicate that violations of consonant co-occurrence restrictions significantly increase error rates in the productions of native speakers, thereby supporting the psychological reality of the constraints.

The use of electropalatography in the assessment and treatment of acquired motor speech disorders in adults: current knowledge and future directions.

Electropalatography (EPG) has been employed to measure speech articulation since the mid-1970s. This technique has predominately been used in experimental phonetic research and in the diagnosis and treatment of articulation disorders in children. However, there is a growing body of research employing EPG to diagnose and treat articulatory impairment associated with acquired motor speech disorder (MSD) in adults. The purpose of this paper was to (1) review the findings of studies pertaining to the assessment and treatment of MSDs in adults using EPG, (2) highlight current methodologies employed, and (3) discuss the potential limitations of EPG in the assessment and treatment of MSDs and examine directions for future applied research and treatment studies.

Effects of transitory lingual nerve impairment on speech: an acoustic study of sibilant sound /s/.

By measuring spectral characteristics of the sibilant /s/ this study investigated whether the reduced orosensory feedback caused by lingual nerve impairment affects the acoustics and articulation of sibilants. A further goal was to examine speakers' capability to compensate for the deviant control of the delicate movements required for the proper production of /s/ by experimentally modifying the function of the tongue in a way that reduces the necessary somatosensory information in articulation. Five healthy men with no speech, language or hearing abnormalities were enrolled. They produced the sibilant /s/ in a variety of phonetic contexts in two sessions: first in normal conditions and then with local anaesthesia of the right lingual nerve. From the speech samples, the spectral characteristics of the sibilant sound (i.e. the centre of gravity, standard deviation, skewness and kurtosis) were analysed acoustically. The results showed that the reduced tactile sensation has effects on the tongue function resulting in individual and variable spectral alterations. The variation between different speakers indicates individual ability to compensate for the effects caused by the sensory dysfunction of the tongue. It seems, therefore, that the compensatory mechanisms for speech production are highly speaker-dependent.

The perceptual characteristics of voice-hallucinations in deaf people: insights into the nature of subvocal thought and sensory feedback loops.

The study of voice-hallucinations in deaf individuals, who exploit the visuomotor rather than auditory modality for communication, provides rare insight into the relationship between sensory experience and how "voices" are perceived. Relatively little is known about the perceptual characteristics of voice-hallucinations in congenitally deaf people who use lip-reading or sign language as their preferred means of communication. The existing literature on hallucinations in deaf people is reviewed, alongside consideration of how such phenomena may fit into explanatory subvocal articulation hypotheses proposed for auditory verbal hallucinations in hearing people. It is suggested that a failure in subvocal articulation processes may account for voice-hallucinations in both hearing and deaf people but that the distinct way in which hallucinations are experienced may be due to differences in a sensory feedback component, which is influenced by both auditory deprivation and language modality. This article highlights how the study of deaf people may inform wider understanding of auditory verbal hallucinations and subvocal processes generally.

Control of voice-onset time in the absence of hearing: a review.

The relation between partial or absent hearing and control of the voicing contrast has long been of interest to investigators, in part because speakers who are born deaf characteristically have great difficulty mastering the contrast and in part for the light it can cast on the role of hearing in the acquisition and maintenance of phonological contrasts in general. One of the phonetic characteristics that distinguish voiced from voiceless plosives in English (p/b, t/d, k/g) is voice onset time (VOT): the interval from plosive release to the onset of voicing of the following vowel. This article first reviews research on VOT anomalies in the speech production of prelingually and postlingually deaf speakers. Then it turns to studies of the mechanisms in speech breathing, phonation and articulation that underlie those anomalies. In both populations of speakers, there is a tendency for the difference between voiced and voiceless VOT to be reduced, to the point for many speakers that there is in effect a substitution of the voiced for the voiceless cognate. The separation of the cognate VOTs can be enhanced when some hearing is restored with a cochlear implant. Both populations also present anomalies in speech breathing that can hinder the development of intraoral pressures and transglottal pressure drops that are required for the production of the VOT contrast. Its successful management further requires critical timing among phonatory and articulatory gestures, most of which are not visible, rendering the VOT contrast a particular challenge in the absence of hearing.