Lian Nijland

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.

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.

Speech perception in children with speech output disorders

Research in the field of speech production pathology is dominated by describing deficits in output. However, perceptual problems might underlie, precede, or interact with production disorders. The present study hypothesizes that the level of the production disorders is linked to level of perception disorders, thus lower‐order production problems (such as childhood apraxia of speech; CAS) are linked to lower‐order perception problems and higher‐order production problems (phonological disorder; PD) are linked to higher‐order perception problems. For this, various perception tasks were administered (non‐word auditory discrimination task, word rhyming task, categorical classification, and discrimination task) in children with CAS, PD, or a mixture. The results show that children with PD only show higher‐order perception problems, whereas children with CAS have difficulties on both lower‐ and higher‐order perception tasks. In children with CAS, difficulties at lower‐order processes might affect the higher‐order processes in development. Furthermore, significant correlations were found between production and perception scores at different levels. Thus, a link between perception and production seems to be evident.

Stability and composition of functional synergies for speech movements in children with developmental speech disorders

UNLABELLED The aim of this study was to investigate the consistency and composition of functional synergies for speech movements in children with developmental speech disorders. Kinematic data were collected on the reiterated productions of syllables spa(/spaː/) and paas(/paːs/) by 10 6- to 9-year-olds with developmental speech disorders (five with speech sound disorder [SSD] and five with subtype childhood apraxia of speech [CAS]) and six normally speaking children using electro-magnetic midsagittal articulography (EMMA). Results showed a higher variability of tongue tip movement trajectories and a larger contribution of the lower lip relative to the jaw in oral closures for the five children with CAS compared to normally developing controls, indicating that functional synergies for speech movements in children with CAS may be both delayed and less stable. Furthermore, the SSD group showed a composition of tongue tip movements that is different from both CAS and controls. These results suggest that the differences in speech motor characteristics between SSD and subtype CAS are qualitative rather than quantitative. At the same time, the results suggest that both SSD and subtype CAS increase movement amplitude as an adaptive strategy to increase articulatory stability. Although in direct comparison no exclusive characteristics were found to differentiate subtype CAS from the group of children with SSD and from normally developing children, these preliminary results are promising for quantifying the role of speech motor processes in childhood speech sound disorders. LEARNING OUTCOMES The reader will be able to: (1) describe the development of speech motor control and explain the role of functional synergies/coordinative structures; (2) explain the measurement of the stability and composition of speech movements; (3) identify the difficulties in studying disordered speech motor development; (4) describe the differences in speech motor characteristics between SSD and subtype CAS; (5) describe the potential role of motor control strategies in developmental speech disorders.

Speech motor coordination in Dutch-speaking children with DAS studied with EMMA

Developmental apraxia of speech (DAS) is generally classified as a ‘speech motor’ disorder. Direct measurement of articulatory movement is, however, virtually non-existent. In the present study we investigated the coordination between articulators in children with DAS using kinematic measurements. The results of articulatory coordination in CCV and CVC syllable productions showed systematic effects of place of articulation in the relative phase values in normally speaking children. Deviant and more variable relative phase values as found in the children with DAS are an indication of coordination problems. The relative phase values are discussed with respect to phonological vs. motoric involvement.

Cognitive functions in Childhood Apraxia of Speech

PURPOSE Childhood apraxia of speech (CAS) is diagnosed on the basis of specific speech characteristics, in the absence of problems in hearing, intelligence, and language comprehension. This does not preclude the possibility that children with this speech disorder might demonstrate additional problems. METHOD Cognitive functions were investigated in 3 domains: complex sensorimotor and sequential memory functions, simple sensorimotor functions, and nonrelated control functions. Seventeen children with CAS were compared with 17 children with normal speech development at 2 occasions within 15 months. RESULTS The children with CAS showed overall lower scores but similar improvement at Occasion 2 compared with the typically developing controls, indicating an overall delay in the development of cognitive functions. However, a specific deviant development in sequential abilities was found as well, indicated by significantly lower scores at Occasion 2 as compared with younger control children at Occasion 1. Furthermore, the scores on the complex sensorimotor and sequential memory tasks were significantly correlated with the severity of the speech impairment. CONCLUSIONS These results suggest that CAS involves a symptom complex that not only comprises errors of sequencing speech movements but implicates comorbidity in nonverbal sequential functioning in most children with CAS.

Auditory processing in speakers with acquired or developmental language disorders. Preface.

On 23–24 January 2006, an international workshop was held in Utrecht, the Netherlands, on Auditory Processing in speakers with acquired or developmental language disorders. It was organized to discuss and disseminate the results of a 4-year research programme with the same name, funded by the Dutch Organization for Scientific Research (NWO). This research programme was a collaboration project carried out by three researchers at three different universities across the Netherlands (Groningen, Nijmegen, Utrecht). A number of national and international guests were invited as experts in the field to comment on the outcomes of the respective research projects and to present their own research. This special issue of Clinical Linguistics and Phonetics contains a selection of papers based on presentations at that workshop. The main applicant of the research grant for the collaboration project was Roelien Bastiaanse (Neurolinguistics Department at Groningen University). Co-applicants were Ben Maassen (Medical Psychology/Department of Paediatric Neurology, Radboud University Nijmegen Medical Centre) and Hugo Quené (Phonetics/Linguistics Department, Utrecht University). The research proposal was a follow-up on the previous collaboration project between the universities of Groningen, Utrecht, and Nijmegen on phonological aspects of speech production in pathological groups of aphasic patients and children with developmental apraxia. This research project led to publication of the book Phonological encoding and monitoring in normal and pathological speech (Hartsuiker, Bastiaanse, Postma, and Wijnen, 2005). The auditory processing project was aimed at making an inventory of phonological processing problems in speech perception in the same pathological groups of aphasic patients (research projects 1 and 3, Groningen and Utrecht) and in children with developmental apraxia (research project 2, Nijmegen), compared to age-matched control groups. One further aim was to establish whether, and to what extent, problems in speech perception in these pathological groups are related to (similar) problems in speech production. Research project 1 (carried out by PhD student Julia Klitsch, Groningen) was on phonological perception problems in aphasic patients. Project 2 (carried out by postdoctoral researcher Lian Nijland, Radboud University Nijmegen Medical Centre) was on perception-production coupling in children with higher-level (i.e. phonological) or lowerlevel (i.e. speech motor) speech production problems. The third research project (carried out by post-doctoral researcher Esther Janse at the Utrecht Institute of Linguistics OTS) was on the processes of lexical activation and deactivation in speech perception in aphasia. The first day of the workshop was meant for ample discussion of the projects’ results in the small circle of invited experts. The second day of the workshop was open to the public and was attended by both researchers (neurolinguistics, speech pathology, and phonetics) and speech and language therapists. There were talks by the researchers of the projects and by the invited experts: Wolfram Ziegler (Clinical Neuropsychology Research Group EKN, City University Munich); James Scobbie (Queen Margaret University College, Speech and Language Sciences, Edinburgh); Martha Burton (Neurology Department, School of Clinical Linguistics & Phonetics, March 2009; 23(3): 177–179On 23–24 January 2006, an international workshop was held in Utrecht, the Netherlands, on Auditory Processing in speakers with acquired or developmental language disorders. It was organized to discuss and disseminate the results of a 4-year research programme with the same name, funded by the Dutch Organization for Scientific Research (NWO). This research programme was a collaboration project carried out by three researchers at three different universities across the Netherlands (Groningen, Nijmegen, Utrecht). A number of national and international guests were invited as experts in the field to comment on the outcomes of the respective research projects and to present their own research. This special issue of Clinical Linguistics and Phonetics contains a selection of papers based on presentations at that workshop. The main applicant of the research grant for the collaboration project was Roelien Bastiaanse (Neurolinguistics Department at Groningen University). Co-applicants were Ben Maassen (Medical Psychology/Department of Paediatric Neurology, Radboud University Nijmegen Medical Centre) and Hugo Quené (Phonetics/Linguistics Department, Utrecht University). The research proposal was a follow-up on the previous collaboration project between the universities of Groningen, Utrecht, and Nijmegen on phonological aspects of speech production in pathological groups of aphasic patients and children with developmental apraxia. This research project led to publication of the book Phonological encoding and monitoring in normal and pathological speech (Hartsuiker, Bastiaanse, Postma, and Wijnen, 2005). The auditory processing project was aimed at making an inventory of phonological processing problems in speech perception in the same pathological groups of aphasic patients (research projects 1 and 3, Groningen and Utrecht) and in children with developmental apraxia (research project 2, Nijmegen), compared to age-matched control groups. One further aim was to establish whether, and to what extent, problems in speech perception in these pathological groups are related to (similar) problems in speech production. Research project 1 (carried out by PhD student Julia Klitsch, Groningen) was on phonological perception problems in aphasic patients. Project 2 (carried out by postdoctoral researcher Lian Nijland, Radboud University Nijmegen Medical Centre) was on perception-production coupling in children with higher-level (i.e. phonological) or lowerlevel (i.e. speech motor) speech production problems. The third research project (carried out by post-doctoral researcher Esther Janse at the Utrecht Institute of Linguistics OTS) was on the processes of lexical activation and deactivation in speech perception in aphasia. The first day of the workshop was meant for ample discussion of the projects’ results in the small circle of invited experts. The second day of the workshop was open to the public and was attended by both researchers (neurolinguistics, speech pathology, and phonetics) and speech and language therapists. There were talks by the researchers of the projects and by the invited experts: Wolfram Ziegler (Clinical Neuropsychology Research Group EKN, City University Munich); James Scobbie (Queen Margaret University College, Speech and Language Sciences, Edinburgh); Martha Burton (Neurology Department, School of Clinical Linguistics & Phonetics, March 2009; 23(3): 177–179