Ben Maassen

Coarticulation patterns in children with developmental apraxia of speech

The aim of this study was to enhance our insight into the underlying deficit in developmental apraxia of speech (DAS). In particular, the involvement of planning and/or programming of speech movements in context was tested by analysing coarticulatory cohesion. For this purpose, second formant frequency measurements were conducted in repetitions of nonsense utterances ([ CV]C=/s,x,b,d/; V=/i,a,u/), and compared across nine children with DAS, six normally speaking (NS) children and six adult women. The results showed both intra- and intersyllabic anticipatory coarticulation in NS children and adult women, in which the intersyllabic coarticulation was stronger in NS children than in adult women. The children with DAS showed more variability as compared to NS children, made, on average, less distinction between the vowels, and showed individually idiosyncratic coarticulation patterns. These results are discussed in the light of a delay as well as a deviance of speech development in children with DAS.

Identification and discrimination of voicing and place-of-articulation in developmental dyslexia

Problems in reading and spelling may arise from poor perception of speech sounds. To study the integrity of phonological access in children with developmental dyslexia (mean age 8 years, 9 months) as compared to two control groups of children (age-matched and matched on reading level), identification and discrimination functions of the features voicing and place-of-articulation were assessed. No differences were found between groups with respect to identification of place-of-articulation. With respect to identification of the voicing contrast, children with developmental dyslexia performed poorer than age-matched controls, but similar to reading-level controls. For the voicing as well as the place-of-articulation contrast, children with developmental dyslexia discriminated poorer than both control groups. This pattern of identification and discrimination performance is discussed relative to the multidimensionality of the speech perception system. The clinical relevance of these perception tasks could be d...Problems in reading and spelling may arise from poor perception of speech sounds. To study the integrity of phonological access in children with developmental dyslexia (mean age 8 years, 9 months) as compared to two control groups of children (age-matched and matched on reading level), identification and discrimination functions of the features voicing and place-of-articulation were assessed. No differences were found between groups with respect to identification of place-of-articulation. With respect to identification of the voicing contrast, children with developmental dyslexia performed poorer than age-matched controls, but similar to reading-level controls. For the voicing as well as the place-of-articulation contrast, children with developmental dyslexia discriminated poorer than both control groups. This pattern of identification and discrimination performance is discussed relative to the multidimensionality of the speech perception system. The clinical relevance of these perception tasks could be demonstrated by significant negative correlations between performance on the perception tasks and reading and spelling ability. This provided additional support for a functional relation between speech perception and reading and spelling in developmental dyslexia.

Child and parental literacy levels within families with a history of dyslexia.

BACKGROUND The present study concerns literacy and its underlying cognitive skills in Dutch children who differ in familial risk (FR) for dyslexia. Previous studies with FR-children were inconclusive regarding the performance of FR-children without dyslexia as compared to the controls. Moreover, van Bergen et al. (2011) recently showed that FR-children with and without dyslexia differed in parental reading skills, suggesting that those who go on to develop dyslexia have a higher liability. The current study concerned 1) the comparison of three groups of children at the end of second grade and 2) the intergenerational transfer of reading and its underlying cognitive skills from parent to child. METHOD Three groups of children were studied at the end of second grade: FR-dyslexia (n = 42), FR-no-dyslexia (n = 99), and control children (n = 66). Parents and children were measured on naming, phonology, spelling, and word and pseudoword reading. RESULTS The FR-dyslexia children were severely impaired across all tasks. The FR-no-dyslexia children performed better than the FR-dyslexia children, but still below the level of the controls on all tasks; the only exception was rapid naming (RAN), on which they were as fast as the controls. Focusing on the FR subsample, parental reading and RAN were related to their offsprings reading status. CONCLUSIONS We replicated and extended van Bergen et al.s study in showing that the FR-children who develop dyslexia are likely to have a higher liability. Both the group comparisons and the parent-child relations highlight the importance of good RAN skills for reading acquisition.

Improvement of voicing in patients with Parkinson's disease by speech therapy.

Speech therapy in PD patients, focusing on an increase of phonatory–respiratory effort, has adverse effects because it raises vocal pitch and laryngeal muscle tension. The authors’ approach, the Pitch Limiting Voice Treatment (PLVT), increases loudness but at the same time sets vocal pitch at a better level. In this study, the Lee Silverman Voice Treatment (“think loud, think shout”) and PLVT (“speak loud and low”) are compared. Both treatments produce the same increase in loudness, but PLVT limits an increase in vocal pitch and prevents a strained or pressed voicing.

The integrated use of maximum performance tasks in differential diagnostic evaluations among children with motor speech disorders

Maximum performance tasks (MPT) were employed to quantify the speech motor capacities of children with dysarthria and developmental apraxia of speech. Specifically, several MPT (i.e. vowel prolongation, fricative prolongation, maximum syllable repetition rate) were conducted among nine carefully selected children with spastic dysarthria, 11 children with developmental apraxia of speech (DAS), and 11 age–matched normal-speaking children. The results indicated that children with spastic dysarthria can be differentiated from both DAS and normal-speaking subjects on only two of the MPT (i.e. monosyllabic repetition rate and vowel prolongation). Children with developmental apraxia of speech, furthermore, differed from the normal-speaking children on fricative prolongation and trisyllabic repetition rate, as well as on measures of trisyllabic repetitive performances (i.e. number of sequencing errors and number of attempts). The findings underscored the clinical importance of MPT for differential diagnosis, and ...

The effect of segmental and suprasegmental corrections on the intelligibility of deaf speech.

Three experiments were conducted to study the effect of segmental and suprasegmental corrections on the intelligibility and judged quality of deaf speech. By means of digital signal processing techniques, including LPC analysis, transformations of separate speech sounds, temporal structure, and intonation were carried out on 30 Dutch sentences spoken by ten deaf children. The transformed sentences were tested for intelligibility and acceptability by presenting them to inexperienced listeners. In experiment 1, LPC based reflection coefficients describing segmental characteristics of deaf speakers were replaced by those of hearing speakers. A complete segmental correction caused a dramatic increase in intelligibility from 24% to 72%, which, for a major part, was due to correction of vowels. Experiment 2 revealed that correction of temporal structure and intonation caused only a small improvement from 24% to about 34%. Combination of segmental and suprasegmental corrections yielded almost perfectly understandable sentences, due to a more than additive effect of the two corrections. Quality judgments, collected in experiment 3, were in close agreement with the intelligibility measures. The results show that, in order for these speakers to become more intelligible, improving their articulation is more important than improving their production of temporal structure and intonation.

Speech motor development in childhood apraxia of speech: generating testable hypotheses by neurocomputational modeling.

Childhood apraxia of speech (CAS) is a highly controversial clinical entity, with respect to both clinical signs and underlying neuromotor deficit. In the current paper, we advocate a modeling approach in which a computational neural model of speech acquisition and production is utilized in order to find the neuromotor deficits that underlie the diversity of phonological and speech-motor symptoms of CAS. Based on existing approaches and behavioral data, we first generated specific hypotheses about the underlying deficits. These hypotheses were then tested in a series of computer simulations, and the resulting speech patterns were compared to the available behavioral data. Finally, the model was used to derive further predictions that can be tested empirically in behavioral experiments and possible new angles for clinical intervention.

Speech Motor Control. New developments in basic and applied research

SECTION ONE: MODELLING OF SPEECH PRODUCTION 1. Apraxia of speech: what the deconstruction of phonetic plans tells us about the construction of articulate language 2. Phonemic, sensory and motor representations in an action-based neurocomputational model of speech production (ACT) 3. Control of movement precision in speech production 4. Variability of North American English /r/ production in response to palatal pertubation SECTION 2: GENETICS AND NEUROLOGY 5. Brain imaging in children 6. Motor speech profile in relation to site of brain pathology 7. Cerebral control of motor aspects of speech production: neurophysiological and functional imaging data SECTION 3: SPEECH MOTOR DEVELOPMENT 8. Dynamic interaction of motor and language factors in normal and disordered development 9. Lip rounding anticipatory control: crosslinguistically lawful and ontogenetically attuned 10. Some organization principles in early speech development SECTION 4: FLUENCY DISORDERS 11. Speech motor variability in people who stutter 12. Speech motor timing and fluency SCTION 5: CLINICAL IMPACT 13. Classification and taxonomy in motor speech disorders: what are the issues? 14. Developmental models of childhood apraxia of speech 15. A neurodevelopmental framework for research in childhood apraxia of speech 16. Distinguishing among motor speech disorders is important: the role of speech pathology in neurologic diagnosis 17. Laryngeal articulatory coupling in three speech disorders 18. Electrical stimulation of deep brain structures and speech SECTION 6: METHODS 19. Recent advances in the physiological assessment of articulation: introducing three dimensional technology 20. Five-dimensional articulography 21. 2D and 3D ultrasound imaging of the tongue in normal and disordered speech

Planning of syllables in children with developmental apraxia of speech

The aim of the present study was to investigate whether children with developmental apraxia of speech (DAS) show a deficit in planning syllables in speech production. Six children with DAS and six normally speaking (NS) children produced high- and low-frequency of occurrence syllable utterances, in which the syllable structure was systematically manipulated in an otherwise unchanging phoneme sequence. Anticipatory coarticulation, using second formant trajectories, and durational structure were analysed. The results showed stronger coarticulation in the children with DAS when compared to the normally speaking children, but in contrast to our expectations, in neither group was a systematic effect of syllable structure on the second format trajectory found. Effects of syllable structure did emerge for durational structure in that durational adjustments were found in the segments of the second syllable. These adjustments were less systematic in children with DAS when compared to normally speaking children. Furthermore, at the prosodic level, normally speaking children showed metrical contrasts that were not realized by the children with DAS. The latter results are interpreted as evidence for a problem in the planning of syllables in speech production of children with DAS, in particular concerning prosodic aspects, which is discussed in relation to the automation of speech production.

Precursors of developmental dyslexia : An overview of the longitudinal dutch dyslexia programme study

Converging evidence suggests that developmental dyslexia is a neurobiological disorder, characterized by deficits in the auditory, visual, and linguistic domains. In the longitudinal project of the Dutch Dyslexia Programme, 180 children with a familial risk of dyslexia (FR) and a comparison group of 120 children without FR (noFR) were followed from the age of 2 months up to 9 years. Children were assessed on (1) auditory, speech, and visual event-related potentials every half year between 2 and 41 months; (2) expressive and receptive language, motor development, behaviour problems, and home-literacy environment by questionnaires at the age of 2 and 3; (3) speech-language and cognitive development from 47 months onwards; and (4) preliteracy and subskills of reading, and reading development during kindergarten and Grades 2 and 3. With regard to precursors of reading disability, first analyses showed specific differences between FR and noFR children in neurophysiological, cognitive, and early language measures. Once reading tests administered from age 7 to 9 years were available, the children were divided into three groups: FR children with and without dyslexia, and controls. Analyses of the differences between reading groups yielded distinct profiles and developmental trajectories. On early speech and visual processing, and several cognitive measures, performance of the non-dyslexic FR group differed from the dyslexic FR group and controls, indicating continuity of the influence of familial risk. Parental reading and rapid naming skills appeared to indicate their offsprings degree of familial risk. Furthermore, on rapid naming and nonverbal IQ, the non-dyslexic FR group performed similarly to the controls, suggesting protective factors. There are indications of differences between the FR and control groups, irrespective of reading outcome. These results contribute to the distinction between the deficits correlated to dyslexia as a manifest reading disorder and deficits correlated to familial risk only.