34 research outputs found

    Electroencephalographic recording of the movement-related cortical potential in ecologically-valid movements:A scoping review

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    The movement-related cortical potential (MRCP) is a brain signal that can be recorded using surface electroencephalography (EEG) and represents the cortical processes involved in movement preparation. The MRCP has been widely researched in simple, single-joint movements, however, these movements often lack ecological validity. Ecological validity refers to the generalizability of the findings to real-world situations, such as neurological rehabilitation. This scoping review aimed to synthesize the research evidence investigating the MRCP in ecologically valid movement tasks. A search of six electronic databases identified 102 studies that investigated the MRCP during multi-joint movements; 59 of these studies investigated ecologically valid movement tasks and were included in the review. The included studies investigated 15 different movement tasks that were applicable to everyday situations, but these were largely carried out in healthy populations. The synthesized findings suggest that the recording and analysis of MRCP signals is possible in ecologically valid movements, however the characteristics of the signal appear to vary across different movement tasks (i.e., those with greater complexity, increased cognitive load, or a secondary motor task) and different populations (i.e., expert performers, people with Parkinson’s Disease, and older adults). The scarcity of research in clinical populations highlights the need for further research in people with neurological and age-related conditions to progress our understanding of the MRCPs characteristics and to determine its potential as a measure of neurological recovery and intervention efficacy. MRCP-based neuromodulatory interventions applied during ecologically valid movements were only represented in one study in this review as these have been largely delivered during simple joint movements. No studies were identified that used ecologically valid movements to control BCI-driven external devices; this may reflect the technical challenges associated with accurately classifying functional movements from MRCPs. Future research investigating MRCP-based interventions should use movement tasks that are functionally relevant to everyday situations. This will facilitate the application of this knowledge into the rehabilitation setting

    Infant and toddler precursors of attentional processes in Fragile X syndrome: A neurodevelopmental perspective

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    With the recent sequencing of the human genome, the following question has attracted much interest: can the function of single genes be linked to specific neural and cognitive processes? Within this context, developmental disorders of known genetic origins have been used as naturally-occurring models to link the function (and dysfunction) of genes with cognition. Fragile X syndrome (FXS) is a genetically inherited disorder associated with the silencing of a single gene involved in experience-dependent changes at glutamatergic synapses. In adulthood, it is associated with core attentional difficulties accompanied by seemingly proficient visuo-perception, but the profile of infants and toddlers has not been investigated. In this thesis, fragile X syndrome is used as a tool to investigate how initial changes in a generalised property of all cortical neurones can nonetheless result, in the adult, in core difficulties in the control of attention. I argue that, even in disorders associated with the silencing of a single gene like FXS, the answer requires a developmental approach. Chapter 1 delineates a theoretical distinction between endogenous and exogenous influences on attentional control, whereas Chapter 2 defines methodological issues in assessing atypical attention, such as tools for the assessment of general developmental level and choices of control groups. Part II focuses on tasks tapping endogenous attention control. In particular, Chapters 3 and 4 examine the control of eye-movements and manual response conflict in infants and toddlers with FXS and in typically developing controls. In contrast, Part III concentrates on the exogenous effects of sudden peripheral onsets on visual orienting (Chapter 5) and of the perceptual salience of targets during visual search (Chapter 6). Finally, Part IV traces longitudinal changes in visual search performance. The findings suggest that, like adults with the syndrome, infant and toddlers with FXS display striking deficits in endogenous attention. However, unlike adults, infants are also characterised by atypical exogenous influences on attention and longitudinal changes in performance point to complex developmental relationships between early and later measures of attention. The findings are discussed in terms of their theoretical implications for fragile X syndrome and other developmental disorders affecting attention. They challenge the notion of direct genotype-phenotype mappings that fail to take development into account

    The use of imagery, mental practice, and relaxation techniques for musical performance enhancement.

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    This document presents information on how imagery, mental practice, and relaxation techniques may be used by musicians and music teachers to enhance performance. In the present study, imagery was defined as a mental process in which an individual consciously imagines an ideal performance in his or her mind. Its effects on performance have been studied extensively in the field of sport psychology. This type of imagery is usually preceded by relaxation techniques which help the musician to associate the simulated performance with a state of calmness and control. Mental practice, a specialized form of imagery, involves more detailed rehearsal and is usually used in the beginning stages of motor learning. The author investigated the impact of these techniques on the areas of self-efficacy or confidence, regulation of anxiety, concentration, and memory in an exploratory study with five graduate pianists

    Human-Computer Interaction

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    In this book the reader will find a collection of 31 papers presenting different facets of Human Computer Interaction, the result of research projects and experiments as well as new approaches to design user interfaces. The book is organized according to the following main topics in a sequential order: new interaction paradigms, multimodality, usability studies on several interaction mechanisms, human factors, universal design and development methodologies and tools

    Early speech motor and language skills in childhood apraxia of speech: evidence for a core deficit in speech motor control?

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    Children with childhood apraxia of speech (CAS) present with significant speech production deficits, the effects of which often persist well into late childhood (American Speech-Language-Hearing Association, 2007; Lewis, Freebairn, Hansen, Iyengar, & Taylor, 2004). Debate has historically surrounded whether the features of CAS are the result of an impairment in linguistic or speech motor systems, or both (American Speech-Language-Hearing Association, 2007). Most research, however, has failed to explicitly consider a developmental perspective of the disorder, arguably limiting the associated interpretations that often (implicitly) assume an established underlying system (Maassen, 2002). One of the key tenets of such a developmental perspective is the possibility of an original core deficit in one system, with negative consequences for aspects of the system that subsequently develop.A mixed-methodology paradigm was employed in the present research in order to explore the core deficit in CAS. Similar paradigms have been applied to the study of dyslexia (Koster et al., 2005; Lyytinen et al., 2001; Viholainen et al., 2006) and autism spectrum disorders (Coonrod & Stone, 2004; Dawson, Osterling, Meltzoff, & Kuhl, 2000; Iverson & Wozniak, 2007), but have yet to be applied to CAS.Study 1 sought to quantify parental report of vocalisation behaviours in children with a clinical diagnosis of CAS. The parents of 20 children with suspected CAS (sCAS) completed a questionnaire focussing on the prelinguistic development of their children as infants. Responses were compared to those from parents of 20 children with Specific Language Impairment (SLI) and 20 children with typically developing (TD) speech and language development. The sCAS children were reported to be significantly less vocal, less likely to have babbled, later in the emergence of first words and later in the emergence of two-word combinations than the TD children. However, the SLI children were reported similarly on many (but not all) items. Despite this similarity, the sCAS group were unique in terms of the presence of reported babbling (35% were reported not to have babbled at all, compared to the TD and SLI children who were all recalled as having babbled in infancy), and the emergence of two word combinations (significantly later than both the TD and SLI groups). In addition, the motor milestones of age of crawling and age of walking were significantly correlated with age of emergence of two-word combinations in the sCAS group, suggesting commonly constrained speech and motor development. Overall, the results provided preliminary support for the notion of atypical prelinguistic vocal development in children with sCAS, and highlighted the importance of further research on the topic.Study 2 applied a retrospective data paradigm in exploring the prelinguistic vocal development of children with CAS. Nine clinically-ascertained children, aged 3 to 4 years and presenting with a range of speech and language profiles (including 3 with suspected CAS), were characterised in terms of operationally-defined CAS characteristics in the first stage (2A) of this study. The battery of tasks included standardised speech and language assessments as well as non-standardised tasks targeting speech production ability. A group of 21 age-matched children with typically developing speech and language skills provided comparison data for the non-standardised tasks. This phase of the study documented CAS characteristics in five of the nine clinical sample participants, with two of these children showing all five of the features investigated. Study 2B examined the early speech, language and motor development of the clinical sample children, via analysis of data available retrospectively for this unique group of children.Their infant profiles were compared to those of 205 infants who had been part of the same community program that the clinical sample had been involved in (and thus had infant data available) but who did not have identified ongoing speech and language issues. Single case comparisons (Crawford & Garthwaite, 2005) revealed that the child with the greatest number and severity of CAS features at preschool age demonstrated significantly poorer expressive skills and a significant dissociation in receptive-expressive abilities in infancy, compared to the typically developing children. Profiles for the other clinical sample children varied considerably.In the third study (Study 3), the development of infants with a family history of CAS (n = 8) was compared to that of infants with no such familial risk (n =8) to further examine the proposed core deficit in CAS. Early speech, language and motor development was tracked at 9, 12, 15, 18 and 24 months. The siblings as a group demonstrated significantly poorer expressive language, speech sound development and fine motor ability than the comparison group, consistent with the notion of a verbal trait deficit (Lewis, Freebairn, Hansen, Taylor et al., 2004). At two years of age, two siblings (and none of the comparison infants) showed clinically-important delays in speech and language development. Inspection of their profiles suggested one infant (SIB2) to present with features consistent with putative early features of CAS (Davis & Velleman, 2000); the other (SIB1) to present with language difficulties not suggestive of CAS.Analysis of their vocalisation samples revealed that while SIB2’s rate of vocalisations at 9 months was not different to that of the comparison group, the nature of the vocalisations were different. While all comparison infants were using canonical syllables at 9 months, SIB2 had not entered this important stage until 12 months, and showed a significantly reduced proportion of canonical syllables at this age (2.5% compared to the comparison infants, who averaged 17%, with none producing less than 6%). Acoustic analyses performed on prelinguistic canonical syllables showed that while duration did not differ, a restricted use of the F1:F2 planar space was noted for SIB2 compared to the typically developing infants, suggesting limited vowel production. Furthermore, a particularly strong correlation between F1 and F2 was observed, suggesting stronger coupling of the articulators. Importantly, the vocalisation data, together with data from standardised assessments, showed a dissociation between speech motor and conceptualiser areas, with a deficit in speech motor control evident in the context of intact conceptual skills for this infant. In contrast, SIB1 (who showed a language delayed profile at 2 years, with no CAS features) did not evidence the types of anomalies identified for SIB2.Taken together, the results of the present research provide support for the viability of a speech motor control deficit account of CAS, when interpreted in a developmental context. As such, they highlight the importance of the prelinguistic period and longitudinal investigations in examining the underlying core deficit in CAS, and suggest important implications for theoretical and clinical conceptualisations of the disorder

    Co-performer empathy in expert ensemble playing

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    This thesis, comprising four empirical studies, investigates the process of co-performer empathy in expert ensemble playing. Following an extensive review of the existing literature relating to both optimal experiences of performance and empathy, it begins by probing the relationship between ensemble musicians’ optimal experiences of performance and their experiences of co-performer empathy through a series of focus group interviews. In addition to co-performer empathy, spontaneous interpretative flexibility (SIF) in performance is identified to be a central feature of optimal experiences of expert ensemble performance. Through observational case studies, involving video-recall, acoustic analyses, and heart-rate measures, a model of process of co-performer empathy and the related process of SIF is constructed. The final model shows co-performer empathy to be a cyclical process grounded in a pre-requisite shared approach, both to the music and to working together. It is often characterised by a special connection between players. It involves the identification of a co-performer’s expressive intention, followed by an appropriate expressive response. Co-performer empathy appears to be a context-specific form of musical empathy that emerges as a group process during ensemble playing, and does not seem to be directly related to trait empathy. Finally, from the findings of these empirical studies, potential techniques for strengthening co-performer empathy and the production of SIF in ensemble playing are proposed
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