Cerebellar gray and white matter volume and their relation with age and manual motor performance in healthy older adults

ObjectivesFunctional neuroimaging and voxel‐based morphometry studies have confirmed the important role of the cerebellum in motor behavior. However, little is known about the relationship between cerebellar gray (GMv) and white matter (WMv) volume and manual motor performance in aging individuals. This study aims to quantify the relationship between cerebellar tissue volume and manual motor performance.Experimental designTo gain more insight into cerebellar function and how it relates to the role of the primary motor cortex (M1), we related cerebellar GMv, WMv, and M1v to manual motor performance in 217 healthy older individuals. Left and right cerebellar GMv and WMv, and M1v were obtained using FreeSurfer. The following motor measures were obtained: grip force, tapping speed, bimanual visuomotor coordination, and manual dexterity.Principal observationsSignificant positive relationships were observed between cerebellar GMv and WMv and grip strength, right cerebellar WMv and right‐hand tapping speed, right cerebellar WMv and dexterity, M1v and grip strength, and right M1v and left‐hand dexterity, though effect sizes were small.ConclusionsOur results show that cerebellar GMv and WMv are differently associated with manual motor performance. These associations partly overlap with the brain‐behavior associations between M1 and manual motor performance. Not all observed associations were lateralized (i.e., ipsilateral cerebellar and contralateral M1v associations with motor performance), which could point to age‐related neural dedifferentiation. The current study provides new insights in the role of the cerebellum in manual motor performance. In consideration of the small effect sizes replication studies are needed to validate these results. Hum Brain Mapp 36:2352–2363, 2015. © 2015 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111082/1/hbm22775.pd

Brain Imaging Correlates of Developmental Coordination Disorder and Associated Impairments

Developmental Coordination Disorder (DCD) is a common developmental disorder characterised by an inability to learn age appropriate complex motor skills. The first aim of this thesis was to characterise additional cognitive impairments and their relationship with motor difficulties in school aged children with DCD. The second aim was to investigate grey and white matter neuroimaging correlates of motor and cognitive deficits identified. Thirty six children aged 8-10 years who met DSM-5 criteria for DCD and an age-matched typically developing group (N=17) underwent standardised assessments of motor, intellectual, attention, speech and language skills as well as structural and diffusion-weighted MRI scans. Grey matter correlates of impairments were identified using subcortical volumetrics and surface-based analyses of cortical morphology. White matter correlates were examined using tractography and fixel-based fibre morphology of the pyramidal tracts, corpus callosum and cerebellar peduncles. Alongside impaired motor skills, children with DCD performed poorer than controls on several domains of executive function (attention and processing speed) and speech motor control. Motor skills did not correlate with impairments in other domains. Cortical thickness was significantly reduced in the left central sulcus in children with DCD compared to controls. Poor motor skills correlated with measures in left sensorimotor circuitry, posterior cingulate cortex and anterior insula. Poor speech motor control was associated with measures in the thalamus and corticobulbar tract. Poor sustained attention was linked to measures in the right superior cerebellar peduncle. Lower processing speed was associated with reduced mean cortical surface area. Children with DCD show co-occurring impairments in attention and speech motor control. DCD is associated with sensorimotor circuits as well as regions that form part of the default mode and salience networks. Disruption of subcortical circuits may underlie additional impairments. This study provides novel evidence of the neural correlates of DCD

Discovering Motor Phenotypes in Autism Spectrum Disorder: A Cross-Syndrome Approach

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder with a behavioral phenotype characterized by persistent deficits in social communication and social interaction accompanied by restricted, repetitive patterns of behaviors, interests, or activities. Currently in the US, approximately 2.5% of children have a diagnosis of ASD. The etiology of ASD is complex, however the disorder does have a strong genetic basis. Specific genetic mutations can lead to neuroanatomical and neurophysiological changes during development resulting in a behavioral phenotype that falls along the ASD spectrum and may result in a diagnosis of ASD. The severity of ASD-specific behaviors falls on a continuum and co-occurring psychiatric disorders are common – adding to the complexity of the disorder. In addition to specific gene mutations implicated in the diagnosis of ASD, specific brain regions are also implicated in ASD that are different from those observed in other common neurodevelopmental disorders – such as Attention-Deficit Hyperactivity Disorder. Studying the neuroanatomical footprint of ASD is a relatively new area of research fueled by the desire to bridge the gap between brain structure and function. Several brain regions implicated in the core social/communication deficits and repetitive behaviors associated with ASD are also involved in various aspects of motor control. These brain areas include cortical regions such as the primary motor cortex (M1), primary somatosensory cortex (S1), inferior parietal lobule (IPL), and subcortical structures that include the cerebellum and basal ganglia. These neuroanatomical findings are bolstered by several studies detailing a wide range of motor deficits in children and adults with ASD. Therefore, studying motor control may provide another means to study the neurological underpinnings of ASD. However, the meaningfulness of nearly all studies detailing motor control deficits in children with ASD is limited due to comparisons limited to a single typically developing (TD) control group. Therefore, the specificity of motor deficits in children with ASD is not well understood since intellectual and behavioral deficits – not specific to children with ASD – may also contribute to the observed motor deficits between children with ASD and TD controls. To overcome this limitation, the current dissertation project employs a cross-syndrome design that includes two additional clinical control groups of children with Fetal Alcohol Spectrum Disorder (FASD) and Attention-Deficit Hyperactivity Disorder (ADHD) with similar intellectual and behavioral impairments as children with ASD. Utilizing this novel approach, motor deficits specific to children with ASD may be identified, allowing for the generation of new hypotheses about the neurological underpinnings of ASD. To bridge the gap between neuroscience and motor control in the study of ASD it is important to understand what findings from both fields of research reveal about ASD. Therefore, an extensive literature review (Chapter 1) is warranted to orient the reader to what is currently known about the underlying neurology and motor deficits associated with ASD. To detail the progression of knowledge about the neuroanatomical deficits associated with ASD, the literature review will funnel from general to more specific findings from animal-models of ASD and human patient studies. Following the neuroanatomical review, a detailed overview of findings from motor control studies on individuals with ASD will be reviewed and discussed in relation to the key neuroanatomical findings in children with ASD. The overall purpose of this dissertation was to identify motor features specifically impaired in children with ASD using a cross-syndrome design. This dissertation explores the three different motor tasks that previous studies have shown to be impaired in children with ASD compared to TD controls. To examine the specificity of previously observed deficits, motor features were extracted from: (1) a precision-grip force tracking task; (2) a postural maintenance task; and (3) a manual dexterity task and compared between children with ASD and children with FASD, ADHD, and TD controls. The first study (Chapter 2) examines group differences in isometric precision-grip static force output features in children with ASD, FASD, ADHD, and TD controls. In this study, grip-force output was maintained at 15% of maximal voluntary contraction (MVC) and no group differences were observed for: (1) relative force accuracy; (2) relative variability; (3) complexity; or (4) frequency structure of the force signal. However, the relative proportion of low frequency oscillations (0-1 Hz) was significantly associated with force accuracy, variability, and complexity in the ASD-group only. In the second study (Chapter 3), dynamic force control features were examined using a ramp-up (0-25% MVC) and ramp-down (25-0% MVC) task. Compared to the TD group, the children with ASD demonstrated significantly: (1) greater relative error during ramp-up and ramp-down; (2) lower ramp-up force-complexity; and (3) greater relative error during transition between ramp-up and ramp-down phases. In the third study (Chapter 4), postural sway features during quiet stance and unipedal stance time were examined. Compared to the FASD, ADHD, and TD groups, the children with ASD demonstrated significantly: (1) greater postural sway area and (2) mediolateral (ML) sway magnitude. Furthermore, children with ASD group demonstrated significantly greater anteroposterior (AP) sway velocity between the TD and FASD groups, and lower ML sway complexity compared to the FASD group only. For unipedal stance, TD children had greater stance times compared to all clinical groups. However, postural sway area was associated with unipedal stance times only in the ASD group. In the fourth study (Chapter 5), manual dexterity of the dominant and non-dominant was examined. Children in the ASD group showed significantly: (1) worse dominant hand dexterity compared to TD controls and (2) worse non-dominant hand dexterity compared to children in the FASD and TD groups. Finally, hand performance asymmetry was significantly lower children with FASD than children without FASD. In summary, this dissertation uses a cross-syndrome approach to identify motor features specifically impaired in children with ASD. Throughout the dissertation, several ASD-specific motor features were identified that align with current knowledge of neuroanatomical deficits associated with ASD. Furthermore, identification of ASD-specific motor features using biomechanics techniques may provide a means to quantitatively study the effects of various pharmacological, behavioral, and non-invasive brain stimulation interventions in clinical settings. Therefore, studying the motor system in children with ASD may have clinical importance due to challenges in quantifying changes in behaviors associated with ASD. In this dissertation, several ASD-specific motor features are identified that can be measured quickly in clinical settings. Further research is required to examine the clinical utility of quantitative motor testing in children with ASD

Manual dexterity correlating with right lobule VI volume in right-handed 14-year-olds

BACKGROUND: Dexterity is a fundamental skill in our everyday life. Particularly, the fine-tuning of reaching for objects is of high relevance and crucially coordinated by the cerebellum. Although neuronal cerebellar structures mediate dexterity, classical whole brain voxel-based morphometry (VBM) has not identified structural correlates of dexterity in the cerebellum. METHODS: Clusters of gray matter (GM) volume associated with the Purdue Pegboard Dexterity Test, a test of fine motor skills and complex upper limb movements, were identified in a cerebellum-optimized VBM analysis using the Spatially Unbiased Infratentorial (SUIT) toolbox in 65 healthy, right-handed 14-year-olds. For comparison, classical whole brain VBM was performed. RESULTS: The cerebellum-optimized VBM indicated a significant positive correlation between manual dexterity and GM volume in the right cerebellum Lobule VI, corrected for multiple comparisons and non-stationary smoothness. The classical whole brain VBM revealed positive associations (uncorrected) between dexterity performance and GM volume in the left SMA (BA 6), right fusiform gyrus (BA 20) and left cuneus (BA 18), but not cerebellar structures. CONCLUSIONS: The results indicate that cerebellar GM volumes in the right Lobule VI predict manual dexterity in healthy untrained humans when cerebellum-optimized VBM is employed. Although conventional VBM identified brain motor network areas it failed to detect cerebellar structures. Thus, previous studies might have underestimated the importance of cerebellum in manual dexterity

A discussion of the necessity of craft education in the 21st century

Craft education has held a permanent place in Estonian and Finnish schools, although its value and appreciation have changed over time. The aim of the article is to discuss the necessity of craft education in today’s world and its possible impact on the development of children and adolescents. The discussion seeks a theoretical interdisciplinary explanation using three perspectives that complement each other. The first describes the challenges of modern society with respect to individual development and schooling. The second deals with Aaron Antonovsky's theory of generalized resistance resources and an individual's possibility to manage in a stressful society. The third addresses the individual as a developing neurological being, along with the effect of learning and practicing motor skills on the human brain. We conclude that craft is a multidisciplinary phenomenon, and that learning and practicing crafts promotes the comprehension of diversity and challenges in life. Additionally, educational craft enriches the learning environment, offering opportunities to develop transferable skills that human beings constantly need in society. In addition, craft provides a balanced way to come to understand the world and one’s role in it, by simultaneously promoting motor and cognitive development and making unique demands on one’s being.Peer reviewe

The relationship between brain structure, motor performance, and early musical training

The current dissertation investigated the relationship between brain structure, motor performance, and musical training. Two structural magnetic resonance imaging (MRI) techniques were used: voxel-based morphometry (VBM) and diffusion tensor imaging (DTI). The first study examined the structural correlates of visuomotor synchronisation performance in normal adults. DTI analyses showed that individual differences in synchronisation performance were negatively correlated with white-matter integrity in a region underlying bilateral sensorimotor cortex. Performance was also positively correlated with radial diffusivity in this region, suggesting the influence of a crossing fibre tract. Fibre tractography identified two fibre populations in this region: the corticospinal tract and superior longitudinal fasciculus (SLF). The SLF links parietal and auditory cortical regions previously shown to be engaged during performance of this task in a functional MRI study with the same sample. VBM analyses showed that grey-matter volume in cerebellar regions important for learning was related to the rate of improvement in synchronisation during learning of the task. The second study explored how musical training during early childhood may have long-lasting effects on brain structure and sensorimotor synchronisation performance. DTI was used to compare white-matter structure in three groups: (1) early-trained musicians (ET; before age seven), (2) late-trained musicians (LT; after age seven), and (3) nonmusicians. Groups were also tested on a visuomotor synchronisation task. ET and LT were matched for years of musical training and experience to isolate the possible effect of age of onset of musical training. Behaviourally, ET outperformed LT and nonmusicians on the synchronisation task. DTI results showed that ET had greater white-matter integrity than LT in the posterior midbody of the corpus callosum, a region connecting bilateral sensorimotor cortices. Measures of white-matter integrity extracted from this region correlated with both synchronisation performance and age of onset of musical training. These findings provide evidence that musical training during a potential sensitive period in development can differentially influence white-matter structure and behavioural performance. Our results are consistent with literature supporting the links between individual differences in brain structure and performance, and training and structural plasticity. They suggest that brain structure is the result of interactions between pre-existing factors, developmental factors, and training and experience

Effetti Immediati del Gioco sulle Abilità Fino-Motorie

Le recenti evidenze scientifiche sui giochi, con particolare riferimento alla letteratura sui video-game, mostrano come queste attività generino miglioramenti nelle abilità cognitive e sensori-motorie. Nel presente elaborato verranno esposti e discussi i risultati ottenuti da uno studio cross-over su un campione di 61 soggetti volontari adulti. Viene infatti comparata la performance in un compito di coordinazione fino-motoria dopo aver giocato ad un video-game o successivamente ad un gioco da tavolo. I risultati ottenuti mostrano un effetto principale del tipo di gioco sulle abilità fino-motoria della mano dominante, per cui punteggi migliori sono ottenuti successivamente ai trial in cui il partecipante giocava con il videogame, rispetto a quando utilizzava il gioco da tavolo. Questi effetti immediati dei video game possono avere delle importanti ricadute cliniche nell’ambito della riabilitazione dei disturbi della coordinazione nello sviluppo. Infatti questi dati avvalorano i risultati di studi precedenti che indagano i miglioramenti nell’abilità motoria fine su popolazioni con disturbo della coordinazione motoria successivamente ad un trattamento con action video game. Oltre al vantaggio sensori-motorio, questo esperimento cross-over rileva che il video-game è valutato dai partecipanti come maggiormente divertente rispetto al gioco da tavolo

Brain structural predispositions for music and language processing

[eng] It has been shown that music and language training can elicit plastic changes on brain structure and function bringing along behavioural benefits. For instance, musicians have been reported to have better auditory discrimination including pitch and speech-in-noise perception, motor-synchronization, verbal memory and general IQ than individuals without formal musical background. Also, bilinguals have shown higher executive function and attention-related abilities than monolinguals. Furthermore, altered functional and structural connectivity can be tracked to brain areas related to the activities most frequently performed by both musicians (instrumentalists and singers) and linguistic experts (such as bilinguals or professional phoneticians). While research in the last decade has devoted important effort to the study of brain plasticity, only a few investigations have addressed the connection between the initial functional or structural properties of brain networks related to auditory-motor function and subsequent language or musical training. Indeed, brain structural markers such as grey matter volume/density or white-matter diffusivity measurements from diffusion tensor imaging (DTI) data, as well as functional measurements from task- related activity or resting-state data from magnetic resonance imaging (MRI) or electroenceplhalography (EEG) have been demonstrated to correlate with consecutive performance and learning in the auditory-motor domain. The main goal of the present dissertation was twofold: we aimed to further the existing knowledge regarding brain plasticity elicited during putative sensitive periods and after long-term music practice, and to explore the white-matter pathways that predict linguistic or musical skills at baseline . Our secondary goals were to confirm previous findings regarding the brain structures involved in music and language processing, as well as to provide evidence of the benefits of usingstructural measurements and correlational analyses between imaging and behavioural data to study inter-individual differences. Study I focused on the comparison between professional pianists and non- musicians observing a complex pattern of increases and decreases in grey matter volume. In comparison to non-musician individuals, pianists showed greater grey matter volume in areas related to motor skill and the automatization of learned movements, as well as reinforcement learning and emotional processing. On the other hand, regions associated to sensorimotor control, score reading and auditory and musical perception presented a reduction in grey matter volume. Study II explored the relationship between white-matter structural properties of the arcuate fasciculus (AF) and the performance of native German speakers in a foreign- language (Hindi) sentence and word imitation task. We found that a greater left lateralization of the AF volume predicted performance on the imitation task. This result was confirmed by using not only a manual deterministic approach but also an automatic atlas-based fibre-reconstruction method, which in addition pointed out to a specific region in the anterior half of the left AF as the most related to imitation ability. Study III aimed to investigate whether the white-matter structural connectivity of the pathways previously described as targets for plasticity mechanisms in professional musicians predicted musical abilities in non-musicians. We observed that the white- matter microstructural organization of the right hemisphere pathways involved in motor-control (corticospinal tract) and auditory-motor transformations (AF) correlated with the performance of non-musician individuals during the initial stages of rhythmic and melodic learning. The present work confirmed the involvement of several brain structures previously described to display plastic effects associated to music and language training in the first stages of audio-motor learning. Furthermore, they challenge previous views regarding music-induced plasticity by showing that expertise is not always or uniquely correlated with increases in brain tissue. This raises the question of the role of efficiency mechanisms derived from professional-like practice. Most importantly, the results from these three studies converge in showing that a prediction-feedback-feedforward loop for auditory-motor processing may be crucially involved in both musical and language learning and skills. We thus suggest that brain auditory-motor systems previously described as participating in native language processing (cortical areas of the dorsal route for language processing and the AF that connects them) may also be recruited during exposure to new linguistic or musical material, being refined after sustained music practice.[spa] Estudios previos muestran que la formación musical y lingüística provoca cambios plásticos en las estructuras y funciones cerebrales, acompañándose también de beneficios conductuales. Por ejemplo, se ha descrito que los músicos poseen mejores habilidades de discriminación auditiva (incluyendo la percepción tonal y la discriminación del habla en un ambiente ruidoso), una mayor capacidad de sincronización motora, así como mejor memoria verbal y coeficiente intelectual general en comparación con personas sin formación musical. Paralelamente, los bilingües muestran mejores funciones ejecutivas y habilidades relacionadas con la atención en comparación con individuos monolingües. Además, las alteraciones en la conectividad cerebral funcional y estructural pueden ser rastreadas estudiando las áreas cerebrales relacionadas con las actividades más utilizadas por músicos (instrumentistas y cantantes) y expertos lingüísticos (como bilingües o fonetistas profesionales). Pese a que en la última década se han dedicado esfuerzos importantes en el campo de la investigación sobre la plasticidad cerebral, sólo unos pocos estudios han tratado de investigar la conexión entre las propiedades iniciales del cerebro, en cuanto a las funciones y estructuras que se relacionan con las funciones auditivo-motoras, y el posterior aprendizaje musical o del lenguaje. Sin embargo, los marcadores estructurales cerebrales, tales como volumen/densidad de materia gris o medidas de difusividad en la sustancia blanca a partir de datos de imagen del tensor de difusión, así como medidas funcionales de la actividad relacionada con una tarea o datos de resting-state (estado de reposo) obtenidos por resonancia magnética o electroencefalografía, han demostrado que pueden correlacionar con el rendimiento y el aprendizaje en el dominio auditivo- motor. En la presente tesis pretendíamos ampliar nuestro conocimiento en cuanto a la plasticidad cerebral obtenida durante los supuestos “períodos sensibles” y después de la práctica musical mantenida en el tiempo, por un lado, y explorar las vías de sustancia blanca que pueden predecir habilidades lingüísticas o musicales al inicio del aprendizaje, por otro lado. Como objetivos secundarios, queríamos confirmar resultados previos con respecto a las estructuras cerebrales involucradas en el procesamiento de la música y el lenguaje, así como apoyar el uso de mediciones estructurales y enfoques correlacionales (entre datos de neuroimagen y conductuales) para estudiar las diferencias inter- individuales. El Estudio I se centró en la comparación entre pianistas profesionales y no músicos, observando un complejo patrón de aumentos y disminuciones en el volumen de materia gris. En comparación con los individuos no músicos, los pianistas mostraron mayor volumen de sustancia gris en áreas relacionadas con la habilidad motora y la automatización de movimientos aprendidos, así como el aprendizaje a través del refuerzo y el procesamiento emocional, mientras que las regiones asociadas al control sensoriomotor, lectura de partituras y percepción auditiva y musical presentaron una reducción del volumen de materia gris. El Estudio II exploró la relación entre las propiedades estructurales de la materia blanca del fascículo arqueado (AF por sus siglas en inglés) y el rendimiento de hablantes nativos de alemán en una tarea de imitación de frases y palabras en una lengua extranjera (hindi). Encontramos que una mayor lateralización del volumen de AF hacia la izquierda predecía el desempeño en la tarea de imitación. Este resultado se confirmó utilizando no sólo un enfoque determinístico-manual sino también una reconstrucción automática (basada en atlas anatómicos) de las fibras de sustancia blanca que, además, señalaba una región específica en la mitad anterior del AF izquierdo como la más relacionada con las capacidades de imitación. El Estudio III tenía como objetivo investigar si la conectividad estructural de vías de sustancia blanca anteriormente descritas como dianas para los mecanismos de plasticidad en músicos profesionales, podría predecir las habilidades musicales en los no músicos. Se observó que la organización micro-estructural de la materia blanca en el hemisferio derecho en vías involucradas en el control motor (tracto corticoespinal) y en transformaciones auditivo-motoras (AF) correlacionaba con el desempeño de individuos no músicos en las etapas iniciales del aprendizaje rítmico y melódico. El presente trabajo ha confirmado la implicación en las primeras etapas del aprendizaje audio-motor de varias estructuras cerebrales que previamente habían mostrado efectos plásticos asociados al aprendizaje musical y del lenguaje. Además, estos resultados desafían las opiniones anteriores sobre la plasticidad inducida por la experiencia musical al demostrar que la experiencia no se correlaciona siempre ni únicamente con un aumento del tejido cerebral, y planteando así preguntas sobre los mecanismos de eficiencia derivados de la práctica musical a nivel profesional. Más importante aún es que los resultados de estos tres estudios convergen mostrando que un bucle de predicción–retroalimentación (feedback)–alimentación directa (feedforward) para el procesamiento auditivo-motor puede estar implicado de manera crucial tanto en el aprendizaje musical como en el aprendizaje de idiomas. Por tanto, sugerimos que los sistemas auditivo-motrices del cerebro, que previamente se habían descrito como participantes en el procesamiento del lenguaje nativo (áreas corticales involucradas en la vía dorsal para el procesamiento del lenguaje, y el AF, que las conecta) también pueden ser reclutados durante la exposición a material lingüístico o musical nuevo, siendo refinado tras años de práctica musical activ