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Evolution has endowed animals with outstanding adaptive behaviours which are grounded in the organization of their sensorimotor system. This paper uses inspiration from these principles of organization in the design of an artificial agent for autonomous driving. After distilling the relevant principles from biology, their functional role in the implementation of an artificial system are explained. The resulting Agent, developed in an EU H2020 Research and Innovation Action, is used to concretely demonstrate the emergence of adaptive behaviour with a significant level of autonomy. Guidelines to adapt the same principled organization of the sensorimotor system to other agents for driving are also obtained. The demonstration of the system abilities is given with example scenarios and open access simulation tools. Prospective developments concerning learning via mental imagery are finally discussed.

Humans can internally sense their muscles. They can also recognize their environment with its objects and are able to navigate through it easily to reach them. How these abilities are gained and interact each other is still an open question in biology. Our aim is to help biologists to understand how a human is able to build his cognitive map and make goal-directed movements. The origin of human capabilities goes back to the fetus stage. We present a theoretical model of the development of the cognitive map of a fetus human from his sensorimotor system. The model integrates the proprioceptions of body limbs and perceptions from the environment and how these cooperate to build a cognitive map, which in turn, is essential for making goal-directed movements to reach different objects in the surrounding environment. We propose a new clustering algorithm called “Frequency-based-means”; which is used to get the proprioceptions and the perceptions that form the association map. Hidden Markov Models are used to model movement learning and production.; Les humains peuvent ressentir leurs muscles. Ils peuvent également reconnaître leur environnement et les objets qui s'y trouvent. Enfin, ils sont capables de se situer dans cet environnement et d'y atteindre des objets. Comment ces capacités sont acquises et interagissent les unes avec les autres au cours du développement ? Cette question demeure ouverte en biologie. Notre objectif est donc d’aider les biologistes à mieux comprendre comment un humain est capable de construire sa carte cognitive et d’effectuer des mouvements dirigés vers un objectif. Sur le plan développemental, l’acquisition des capacités sensorimotrices humaines débute avec le fœtus. Nous présentons ici un modèle théorique du développement de la carte cognitive d’un fœtus humain à partir de son système sensorimoteur. Le modèle intègre les proprioceptions des membres du corps et les perceptions de l’environnement et comment celles-ci coopèrent pour construire une carte cognitive. Cette carte est essentielle afin d'effectuer des mouvements dirigés vers un objectif et atteindre différents objets au sein de l’environnement. Nous proposons un nouvel algorithme de clustering appelé “Frequency-based-means”, qui est utilisé pour obtenir les proprioceptions et les perceptions qui constituant la carte d’association. Des modèles de Markov cachés sont utilisés pour modéliser l’apprentissage et la production de mouvements.

Humans can internally sense their muscles. They can also recognize their environment with its objects and are able to navigate through it easily to reach them. How these abilities are gained and interact each other is still an open question in biology. Our aim is to help biologists to understand how a human is able to build his cognitive map and make goal-directed movements. The origin of human capabilities goes back to the fetus stage. We present a theoretical model of the development of the cognitive map of a fetus human from his sensorimotor system. The model integrates the proprioceptions of body limbs and perceptions from the environment and how these cooperate to build a cognitive map, which in turn, is essential for making goal-directed movements to reach different objects in the surrounding environment. We propose a new clustering algorithm called “Frequency-based-means”; which is used to get the proprioceptions and the perceptions that form the association map. Hidden Markov Models are used to model movement learning and production.; Les humains peuvent ressentir leurs muscles. Ils peuvent également reconnaître leur environnement et les objets qui s'y trouvent. Enfin, ils sont capables de se situer dans cet environnement et d'y atteindre des objets. Comment ces capacités sont acquises et interagissent les unes avec les autres au cours du développement ? Cette question demeure ouverte en biologie. Notre objectif est donc d’aider les biologistes à mieux comprendre comment un humain est capable de construire sa carte cognitive et d’effectuer des mouvements dirigés vers un objectif. Sur le plan développemental, l’acquisition des capacités sensorimotrices humaines débute avec le fœtus. Nous présentons ici un modèle théorique du développement de la carte cognitive d’un fœtus humain à partir de son système sensorimoteur. Le modèle intègre les proprioceptions des membres du corps et les perceptions de l’environnement et comment celles-ci coopèrent pour construire une carte cognitive. Cette carte est essentielle afin d'effectuer des mouvements dirigés vers un objectif et atteindre différents objets au sein de l’environnement. Nous proposons un nouvel algorithme de clustering appelé “Frequency-based-means”, qui est utilisé pour obtenir les proprioceptions et les perceptions qui constituant la carte d’association. Des modèles de Markov cachés sont utilisés pour modéliser l’apprentissage et la production de mouvements.

International audience; Most of our daily interactions with objects occur in the space immediately surrounding the body, i.e. the peripersonal space. The peripersonal space is characterized by multisensory processing of objects which are coded in terms of potential actions, specifying for instance whether objects are within reach or not. Our recent work suggested a link between exposure to a new force field, which changed the effector dynamics, and the representation of peripersonal space. To better understand the interplay between the plasticity of the motor system and peripersonal space representation, the present study examined whether changing the direction of the force field specifically modified the perception of action boundaries. Participants seated at the centre of an experimental platform estimated visual targets’ reachability before and after adapting upper-limb reaching movements to the Coriolis force generated by either clockwise or counter clockwise rotation of the platform (120°/s). Opposite spatial after-effects were observed, showing that force-field adaptation depends on the direction of the rotation. In contrast, perceived action boundaries shifted leftward following exposure to the new force field, regardless of the direction of the rotation. Overall, these findings support the idea that abrupt exposure to a new force field results in a direction-specific updating of the central sensorimotor representations underlying the control of arm movements. Abrupt exposure to a new force field also results in a nonspecific shift in the perception of action boundaries, which is consistent with a contraction of the peripersonal space. Such effect, which does not appear to be related to state anxiety, could be related to the protective role of the peripersonal space in response to the uncertainty of the sensorimotor system induced by the abrupt modification of the environment.

Standing can be understood as a motor process in addition to the stereotypes of movement described by Janda. Atypical stress during standing leads to overstraining of myofascial structures and to pain. The search for a specific examination possibility with the prospect of individual therapy recommendations was the reason for the development of this score.In this study 80 healthy volunteers were examined for their stance stability by means of established as well as proportionally newly described test procedures. The equally weighted results were combined into a score and its standard values were determined.For the age group 18-44 years old the norm is the completion of 10 out of the total of 13 individual tasks. For the age group 45-59 years old, according to current measurements 8 out of 13 achieved points are the norm. In the age group from the age of 60 years onwards, no reliable statements can so far be made.The age group up to 44 years old provided reliable data. The age group above that shows at least a clear trend. The existing tests and scores are increasingly concerned with the risk of falling and the dexterity in movements and complex tasks. The status as a motor stereotype has not yet been described. After an examination using the Jena standing stability (JESS) score it is possible to make statements about individual therapy priorities.The JESS score is a practicable test to verify the standing stereotype. The extension of the norm group by including further study participants will decide on a stabilization or modification of the current results. The testing of further cohorts will show to what extent these items are sensitive to changes caused by training methods and whether the score can also be used to congruently map clinical changes.HINTERGRUND: Der Stand bzw. das Stehen kann neben den von Janda beschriebenen Bewegungsstereotypen ebenfalls als motorischer Prozess begriffen werden. Atypische Belastungen während des Stehens führen zur Überbeanspruchung myofaszialer Strukturen und zu Schmerz. Die Suche nach einer dezidierten Untersuchungsmöglichkeit mit der Aussicht auf individuelle Therapieempfehlungen, war Anlass für die Erarbeitung dieses Scores.Es wurden 80 gesunde Probanden mittels etablierter sowie anteilig neu beschriebener Testverfahren auf ihre Standstabilität hin untersucht. Die gleichgewichteten Ergebnisse wurden zu einem Score zusammengefasst und dessen Normwerte bestimmt.Für die Altersklasse der 18- bis 44-Jährigen ist die Norm das Erfüllen von 10 der insgesamt 13 Einzelaufgaben. Für die 45- bis 59-Jährigen sind nach aktuellen Messungen 8 von 13 erreichten Punkten die Norm. In der Altersgruppe ab dem 60. Lebensjahr können bisher keine belastbaren Aussagen getroffen werden.Belastbare Daten liefert die Altersgruppe bis 44 Jahre. Die Altersgruppe darüber zeigt zumindest einen deutlichen Trend. Die existierenden Tests bzw. Scores setzten sich verstärkt mit dem Sturzrisiko und der Geschicklichkeit bei Bewegungen und komplexen Aufgaben auseinander. Der Stand als motorischer Stereotyp wurde bisher noch nicht beschrieben. Nach einer Untersuchung mittels Jenaer-Stand-Stabilitäts-Score (JESS-Score) ist es möglich, Aussagen zu individuellen Therapieschwerpunkten zu treffen.Der JESS-Score stellt einen praktikablen Test zur Verifizierung des Standstereotyps dar. Die Erweiterung der Normgruppe durch Einschluss weiterer Studienteilnehmer wird über eine Verstetigung oder Modifikation der aktuellen Ergebnisse entscheiden. Die Testung weiterer Kohorten wird zeigen, inwieweit diese Items sensitiv für Veränderungen durch Trainingsmethoden sind und ob mit dem Score auch klinische Änderungen kongruent abgebildet werden können.

Estrategias Lúdico-Pedagógicas de Estimulación Temprana Encaminadas a Favorecer el Desarrollo Psicomotriz en Niños-Niñas de 2-3 Años, Colegio 1-2-3 Por Mí, Área Metropolitana de Bucaramanga, es el trabajo de grado desarrollado para obtener el título de Licenciada en Educación preescolar, que involucra a institución educativa, maestros, y padres de familia porque esta es una de las etapas más significativas e influyentes del desarrollo humano, formando las primeras bases y estructuras de la persona. La metodología utilizada fue la investigación acción, enfoque cualitativo, método inductivo que incluyó a 20 niños-niñas del grado párvulos cuatro, contando como instrumentos de recolección de información la observación participante, entrevista semiestructurada a docentes de preescolar de la institución educativa, y el diario de campo. Como resultado de ello se desarrollaron nueve actividades de estimulación temprana, socialización de las estrategias con maestras de preescolar y la escuela para padres con el fin de comprometerlos en el proceso de enseñanza-aprendizaje de sus hijos, y una guía de estimulación temprana dirigida a maestros y padres de familia, proceso del que se concluye que las actividades lúdicas deben propiciar la interacción de niños-niñas con su entorno, facilitando el estímulo de los procesos psicomotrices, otorgar libertad y continuidad para que tengan una participación activa en su propio aprendizaje, además del equilibrio adecuado en su crecimiento físico, intelectual y emocional. Las recomendaciones giran en torno a que desde el interior de las instituciones educativas se deben crear espacios y/o ambientes que cautiven la atención de los niños-niñas integrándolos niños y niñas a través del juego a fin de mejorar su habilidad psicomotora. Playful and Early Stimulation Pedagogical Strategies to Promote Psychomotor Development in Children-2-3 Years Old, School 1-2-3 For Me, Bucaramanga Metropolitan Area, is the grade work developed to obtain the title of Graduate in Preschool Education , which involves an educational institution, teachers, and parents because this is one of the most significant and influential stages of human development, forming the first bases and structures of the person. The methodology used was action research, qualitative approach, inductive method that included 20 boys and girls of the fourth grade, counting as participant information collection instruments, semi-structured interview to preschool teachers of the educational institution, and the newspaper field As a result, nine early stimulation activities, socialization of strategies with preschool teachers and the school for parents were developed in order to engage them in the teaching-learning process of their children, and an early stimulation guide for teachers and parents, a process that concludes that recreational activities should encourage the interaction of children with their environment, facilitating the stimulation of psychomotor processes, granting freedom and continuity so that they have an active participation in their own learning, in addition of proper balance in their physical, intellectual and emotional growth . The recommendations revolve around the fact that from within the educational institutions spaces and / or environments that captivate the attention of the children must be created by integrating the boys and girls through the game in order to improve their psychomotor ability. Licenciado en Educación Preescolar http://www.ustadistancia.edu.co/?page_id=3956 Pregrado

The sensorimotor system of fish endows them with remarkable swimming performance that is unmatched by current underwater robotic vehicles. To close the gap between the capabilities of fish and the capabilities of underwater vehicles engineers are investigating how fish swim. In particular, engineers are exploring the sensorimotor systems of fish that control the motion of fins. It is generally accepted that specialized neural circuits (known as central pattern generators) within the sensorimotor system produce the periodic drive signal that is used to control the motion of fins. An important aspect of these circuits is that their output signal can be modified by sensory feedback. Specifically, the way in which sensory feedback signals are applied to a CPG (i.e. the sensory feedback topology) affects the CPG's entrainment characteristics. This has been shown in simulation but has not been investigated in a robot interacting in the real-world. Furthermore, CPG-based control has only limitedly been applied to fish like robots and many questions remain as to how it should be applied to these types of systems. In this work we examine the effect of sensory feedback topology on the entrainment characteristics of a CPG-based neural oscillator driving three different foils swimming in flow. Additionally, we investigate how sensory feedback should be acquired from a foil and applied to a neural oscillator to promote beneficial swimming characteristics.

When we act, our brains register the visual feedback of the outcome of our actions only approximately 150 ms after sending the motor commands to the muscles. By anticipating the sensory consequences of our actions, temporal prediction mechanisms help us to accurately perform time-critical motor actions, such as catching a ball, and to experience the world as temporally coherent. It remains unclear whether these prediction mechanisms can adapt in a general way to changing sensory feedback delays, as they occur, for instance, when neural processing times increase during development. We here used Augmented Reality to train participants for one hour in a range of everyday life tasks with different levels of artificial visual feedback delay: 0 ms (No Delay), 100 ms (Small Delay) and 250 ms (Large Delay). We tested whether temporal aftereffects (increased motor-anticipation) generalize across different perceptual and motor tasks that participants did not practice during training and that involve different aspects of sensorimotor integration (motor planning, feedback control, sensorimotor time perception). Our results show a consistent temporal aftereffect of 33% across tasks and levels of delay. This suggests that the human sensorimotor system can adapt to the presence of visual feedback delays in a that affects sensorimotor prediction in general.

Background When exposed to a novel dynamic perturbation, participants adapt by changing their movements’ dynamics. This adaptation is achieved by constructing an internal representation of the perturbation, which allows for applying forces that compensate for the novel external conditions. To form an internal representation, the sensorimotor system gathers and integrates sensory inputs, including kinesthetic and tactile information about the external load. The relative contribution of the kinesthetic and tactile information in force-field adaptation is poorly understood. Methods In this study, we set out to establish the effect of augmented tactile information on adaptation to force-field. Two groups of participants received a velocity-dependent tangential skin deformation from a custom-built skin-stretch device together with a velocity-dependent force-field from a kinesthetic haptic device. One group experienced a skin deformation in the same direction of the force, and the other in the opposite direction. A third group received only the velocity-dependent force-field. Results We found that adding a skin deformation did not affect the kinematics of the movement during adaptation. However, participants who received skin deformation in the opposite direction adapted their manipulation forces faster and to a greater extent than those who received skin deformation in the same direction of the force. In addition, we found that skin deformation in the same direction to the force-field caused an increase in the applied grip-force per amount of load force, both in response and in anticipation of the stretch, compared to the other two groups. Conclusions Augmented tactile information affects the internal representations for the control of manipulation and grip forces, and these internal representations are likely updated via distinct mechanisms. We discuss the implications of these results for assistive and rehabilitation devices.

Background: Prior research suggests that the amount of experience an individual has with an action influences the degree to which the sensorimotor systems of their brain are involved in the subsequent perception of those actions. Less is known about how action experience and conceptual understanding impact sensorimotor involvement during imitation. We sought to explore this question by comparing a group of sign language users to a group of non-signers. We pitted the following two hypotheses against each other: 1) Deaf signers will show increased sensorimotor activity during sign imitation, and greater differentiation between sign types, due to greater prior experience and conceptual understanding of the signs; versus 2): Deaf signers will show less sensorimotor system activity and less differentiation of sign types in the sensorimotor system, because for those individuals sign imitation involves language systems of the brain more robustly than sensorimotor systems. We collected electroencephalograms (EEG) while the two groups imitated videos showing one-handed and two-handed ASL signs. Time-frequency data analysis was performed on alpha- and beta-range oscillations while they watched signs with the intent to imitate, and imitated the signs. During observation, deaf signers showed early differentiation in alpha/beta power between the one- and two-handed sign conditions, whereas hearing non-signers did not discriminate between the sign categories this way. Significant differences between groups were seen during sign imitation, wherein deaf signers showed desynchronization of alpha/beta EEG signals, and hearing non-signers showed increased power. The study suggests that in an imitative context, deaf signers engage anticipatory motor preparation in advance of action production, while hearing non-signers engage slower, more memory-related processes to help them complete with the complex task.

Animals readily execute learned behaviors in a consistent manner over long periods of time, yet no equally stable neural correlate has been demonstrated. How does the cortex achieve this stable control? Using the sensorimotor system as a model of cortical processing, we investigated the hypothesis that the dynamics of neural latent activity, which capture the dominant co-variation patterns within the neural population, must be preserved across time. We recorded from populations of neurons in premotor, primary motor, and somatosensory cortices as monkeys performed a reaching task, for up to two years. Intriguingly, despite steady turnover in the recorded neurons, the low-dimensional latent dynamics remained stable. The stability allowed reliable decoding of behavioral features for the entire timespan, while fixed decoders based directly on the recorded neural activity degraded substantially. We posit that stable latent cortical dynamics within the manifold are the fundamental building blocks underlying consistent behavioral execution., This work was supported in part by Grant FP7-PEOPLE-2013-IOF-627384 from the Commission of the European Union and Grant 2017-T2/TIC-5263 from the Community of Madrid (J.A.G.), by Grant F31-NS092356 from the National Institute of Neurological Disorder and Stroke and Grant T32-HD07418 from the National Institute of Child Health and Human Development (M.G.P.), by Grant DGE-1324585 from the National Science Foundation (R.H.C.), and by Grants NS095251 (L.E.M.) and NS053603 (S.A.S. and L.E.M.) from the National Institute of Neurological Disorder and Stroke.

A sudden change in dynamics produces large errors leading to increases in muscle co-contraction and feedback gains during early adaptation. We previously proposed that internal model uncertainty drives these changes, whereby the sensorimotor system reacts to the change in dynamics by up regulating stiffness and feedback gains to reduce the effect of model errors. However, these feedback gain increases have also been suggested to represent part of the adaptation mechanism. Here, we investigate this by examining changes in visuomotor feedback gains during gradual or abrupt force field adaptation. Participants grasped a robotic manipulandum and reached while a curl force field was introduced gradually or abruptly. Abrupt introduction of dynamics elicited large initial increases in kinematic error, muscle co-contraction and visuomotor feedback gains, while gradual introduction showed little initial change in these measures despite evidence of adaptation. After adaptation had plateaued,there was a change in the co-contraction and visuomotor feedback gains relative to null field movements, but no differences (apart from the final muscle activation pattern) between the abrupt and gradual introduction of dynamics. This suggests that the initial increase in feedback gains is not part of the adaptation process, but instead an automatic reactive response to internal model uncertainty. In contrast, the final level of feedback gains is a predictive tuning of the feedback gains to the external dynamics as part of the internal model adaptation. Together, the reactive and predictive feedback gains explain the wide variety of previous experimental results of feedback changes during adaptation.

Previous research has established that observing another in pain activates both affective and sensorimotor cortical activity that is also present during the first-hand experience of pain. Some researchers have taken this “mirroring” response as indicative of empathic processing. However, very little work has explored the downstream behavioral effects of empathic pain observation. The aim of this dissertation is to begin to fill this gap in the literature by exploring the relationship between empathic pain observation, overt motor behaviours, and sensorimotor activity. In chapters 2-4, I provide robust evidence that observing pain inflicted on another person leads to faster reaction time responses. This effect is shown to be temporally extended (by at least 500ms after pain observation), effector-general (affecting both finger and foot responses), influenced by top-down (i.e., instructions to explicitly empathize) but not bottom-up (i.e., the perceived level of pain) factors, and is not influenced by adaptive (approach/withdraw) behaviours. In chapter 5, I show that sensorimotor activity, measured via TMS-induced Motor Evoked Potentials, increases while observing another in pain regardless whether the observer is preparing to make an action vs. passively observing the stimuli. These results run counter to the literature, and I provide several explanations for why these results were found. Lastly, in chapter 6, I show that sensorimotor activity, measured via Mu and Beta suppression, also increases while observing another in pain regardless whether the observer is preparing to make an action vs. passively observing the stimuli. Interestingly, I do not find significant correlations between sensorimotor activity during pain observation and faster reaction times after pain observation. I embed these findings in relation to the wider social neuroscience of empathy literature and discuss several limitations and challenges in empirically measuring “empathy” as a psychological construct. Overall, this dissertation furthers our understanding of empathy for pain by highlighting the behavioural consequences of pain observation and its connection (or rather, lack thereof) to sensorimotor activity during pain observation. Thesis Doctor of Philosophy (PhD) Past research suggests that overlapping brain activity during the first-hand experience of pain and pain observation may be indicative of empathy. However, very little work has been done to explore how pain observation influences overt behaviours. This thesis investigates this issue by having participants complete a reaction time task while watching videos of needles stabbing a person’s hand. The findings reported in this thesis suggests that observing another in pain facilitates motor behaviours (i.e., faster reaction times); this facilitation extends 500ms after pain observation, affects both the hand and feet, is accentuated by instructing participants to explicitly empathize, and is not influenced by approach vs. withdraw movements. Brain activity in the motor system was also found to increase during pain observation. Overall, this thesis begins the discussion of how empathic pain observation influences explicit motor behaviours, and how such behaviours may be related to brain activity.

In our daily life we often make complex actions comprised of linked movements, such as reaching for a cup of coffee and bringing it to our mouth to drink. Recent work has highlighted the role of such linked movements in the formation of independent motor memories, affecting the learning rate and ability to learn opposing force fields. In these studies, distinct prior movements (lead-in movements) allow adaptation of opposing dynamics on the following movement. Purely visual or purely passive lead-in movements exhibit different angular generalization functions of this motor memory as the lead-in movements are modified, suggesting different neural representations. However, we currently have no understanding of how different movement kinematics (distance, speed or duration) affect this recall process and the formation of independent motor memories. Here we investigate such kinematic generalization for both passive and visual lead-in movements to probe their individual characteristics. After participants adapted to opposing force fields using training lead-in movements, the lead-in kinematics were modified on random trials to test generalization. For both visual and passive modalities, recalled compensation was sensitive to lead-in duration and peak speed, falling off away from the training condition. However, little reduction in force was found with increasing lead-in distance. Interestingly, asymmetric transfer between lead-in movement modalities was also observed, with partial transfer from passive to visual, but very little vice versa. Overall these tuning effects were stronger for passive compared to visual lead-ins demonstrating the difference in these sensory inputs in regulating motor memories. Our results suggest these effects are a consequence of state estimation, with differences across modalities reflecting their different levels of sensory uncertainty arising as a consequence of dissimilar feedback delays.

Despite the great number of test batteries already known to assess the behavior of genetically modified and inbred strains of mice, only a few of them focus on basic neurological parameters. The purpose of the battery test proposed is to settle a specific methodology to characterize the phenotype of neurological disease models in mutant or genetically modified mice. This methodology is simple and efficient in order to analyze several parameters, including general activity, sensory nervous system, sensorimotor system, central nervous system and autonomous nervous system. This can aid the choice of specific additional tests as well as the determination of an interrelationship among phenotypic alterations observed. Although being efficient for a first analysis of a mouse model, interpretation of the results must be carefully made because phenotype manifestation may vary due to many parameters, including mouse strain, environmental and housing condition, animal-experimenter interaction, sample size and tests order. It is important to consider as a critical point if handling procedures are aversive. The results acquired with the analysis of 18 parameters together provide preliminary data to characterize mouse phenotype and helps selecting more specific tests.

Embodied cognition is a theory that grounds the idea that the many aspects of human cognition are influenced by the combination of experiences in the physical world, including tactile interaction with daily use products and physical interfaces, and the direct influence of the sensorimotor system over the mind itself.

Little is known about how disrupted vision affects visual reliance during postural control. postural control. Twenty-four physically active adults volunteered to participate in the study. Static postural control was quantified with center of pressure measures during a one-legged balance test with four different visual inputs (eyes-open (EO), high frequency of strobe vision (HSV), low frequency of strobe vision (LSV), and eyes-closed (EC)) and on two different surfaces (firm and foam). Dynamic postural control was calculated by the dynamic postural stability index and the Y-Balance test for three different visual inputs (EO, HSV, and LSV) and the two different surfaces. Romberg ratios (HSV/EO, LSV/EO, and EC/EO) were then calculated and used for statistical analysis to assess visual contribution during postural control. In the results, Romberg ratios were higher when people were on the foam surface than the firm surface in center of pressure total path in medial-lateral and anterior-posterior directions (p < 0.05, both directions). Similarly, Romberg ratios were higher on the foam surface than the firm surface in dynamic stability index in medial-lateral and anterior-posterior directions (p < 0.05, both directions). Stroboscopic glasses could alter visual reliance when the somatosensory system is disturbed by a foam pad during both static and dynamic postural control. Clinicians could use the glasses to manipulate visual reliance during dynamic balance training for patients with musculoskeletal injuries.

BACKGROUND White matter (WM) blood oxygenation level-dependent (BOLD) signals are reported to be related to neural activity. However, sensitivity of WM BOLD signals to disease remains unclear. PURPOSE To investigate WM BOLD signal changes, directional variations of resting-state correlations in sensorimotor system in patients with pontine strokes, and to determine the relationship between WM BOLD signals and motor deficits. STUDY TYPE Prospective. SUBJECTS Ethical approval was obtained from the local Ethics Committee and each participant gave written informed consent. Sixteen patients with focal pontine lesions and 16 age-matched control subjects were included. FIELD STRENGTH/SEQUENCE 3.0T T1 -weighted anatomic images using a 3D magnetization-prepared rapid gradient-echo sequence. Resting-state fMRI images using gradient-echo echo-planar imaging sequence. Diffusion-weighted images using single-shot spin-echo diffusion echo-planar imaging. ASSESSMENT Relevant WM tracts in the sensorimotor system by region of interest-wise analysis were identified. Power spectra of BOLD signals and anisotropy of resting-state correlations were measured in sensorimotor system and compared between two groups. Their relationships with clinical scores were analyzed. STATISTICAL TESTS Two-sample t-test; partial correlation analysis. RESULTS Power spectra of BOLD signals in nerve tracts on the ipsilesional side were significantly decreased (P

Background Deficits in the sensorimotor system and its peripheral and central processing of the affected body part might be a contributing factor to chronic low back pain (CLBP). Hence, sensorimotor assessment is important. Valid and reliable sensorimotor measurement instruments are needed. Objective To investigate the reliability and validity of sensorimotor measurement instruments for people with chronic low back pain (CLBP). Design Systematic review and meta-analysis. Methods The review was undertaken using the COSMIN guidelines. Databases were searched for studies investigating the clinimetric properties of sensorimotor tests in people with CLBP. The methodological study quality was rated by two independent reviewers using the COSMIN 4-point rating checklist. Results Ten studies were included covering six sensorimotor measurement instruments with findings for reliability/measurement error, known-groups validity and convergent validity. The methodological quality ranged from poor to good, with only one study rated as good. There was insufficient evidence of enough quality to assess reliability/measurement error or convergent validity. Two-point discrimination, laterality judgement and movement control tests had moderate evidence supporting their ability to distinguish between healthy people and those with CLBP. Conclusions Two-point discrimination, laterality judgment and movement control tests demonstrate the greatest level of known-groups validity for people with CLBP. However, as the reliability of these measurement tools has yet to be established, this validity data should be interpreted cautiously. Further research is warranted to investigate the clinimetric properties of these sensorimotor techniques.

WstępCelem badania jest wykazanie związku między skróceniem czynnościowym mięśnia prostego uda i mięśni kulszowo-goleniowych a kinestezją stawu kolanowego u pacjentów po zerwaniu więzadła krzyżowego przedniego [ACL].Materiał i metodyBadaniem objęto grupę 35 mężczyzn z zerwaniem ACL (bez rekonstrukcji) w wieku od 18 do 43 lat (28 ± 7,4 roku). Funkcjonalne skrócenie wyżej wymienionych mięśni oceniano zarówno na zdrowej, jak i kontuzjowanej nodze. Kinestezję stawu kolanowego oceniano za pomocą aparatu BTE Primus RS, badając odchylenie kątowe od środka zakresu ruchu w stawie kolanowym z i bez kontroli wzroku.WynikiStwierdzono statystycznie istotną dodatnią korelację między funkcjonalnym skróceniem mięśni kulszowo-goleniowych a kinestezją dla ruchu zgięcia ocenianego w warunkach bez kontroli wzroku. Ponadto stwierdzono istotną statystycznie ujemną korelację między funkcjonalnym skróceniem mięśnia prostego uda nogi uszkodzonej a kinestezją ruchu zgięcia kolana ocenianego w warunkach bez kontroli wzroku.WnioskiDeficyt propriocepcji kolana koreluje z funkcjonalnym skróceniem mięśni uda. Pacjenci z funkcjonalnym skróceniem mięśnia prostego uda mają lepszą kinestezję stawu kolanowego, natomiast u pacjentów z funkcjonalnym skróceniem ścięgien podkolanowych stwierdzono gorszą kinestezję stawu kolanowego.

The current study aimed to examine postural control performance during a single-leg balance task in elderly individuals with and without a previous history of lateral ankle sprain (LAS). Eighteen adults with a previous history of LAS (mean age = 66 years old) and 12 healthy controls (mean age = 65 years old) were included in the study. Participants performed three trials of a single-leg balance task during an eyes-opened condition for 20-s. Center of pressure (COP) trajectories in the anteroposterior (AP) and mediolateral (ML) directions were collected with a force plate. The following postural control measures were calculated in the AP and ML directions: 1) Sample Entropy (SampEn); 2) Approximate Entropy (ApEn); 3) mean of Time-to-Boundary minima (mean TTB); and 4) COP velocity (COPV). Older-age participants with a history LAS exhibited lower ApEn-AP, SampEn-AP, and SampEn-ML values compared to healthy controls (p 0.05). The information gained from this investigation indicates more rigid postural control patterns, less adaptability, and more difficulty maintaining COP during a single-leg balance task in adults with a previous history of LAS. Our data suggest that there is a need to consider history of musculoskeletal injury when evaluating factors for postural control and fall risk in the elderly. Future investigations are needed to assess the effect of LAS on age-related declines in postural control and discern associations between potential risk factors of fall-related injuries and LAS in an elderly population.

Action perception and action production are assumed to be based on an internal simulation process that involves the sensorimotor system. This system undergoes changes across the life span and is assumed to become less precise with age. In the current study, we investigated how increasing age affects the magnitude of interference in action production during simultaneous action perception. In a task adapted from Brass et al. (Brain Cogn 44(2):124-143, 2000), we asked participants (aged 20-80 years) to respond to a visually presented finger movement and/or symbolic cue by executing a previously defined finger movement. Action production was assessed via participants' reaction times. Results show that participants were slower in trials in which they were asked to ignore an incongruent finger movement compared to trials in which they had to ignore an incongruent symbolic cue. Moreover, advancing age was shown to accentuate this effect. We suggest that the internal simulation of the action becomes less precise with age making the sensorimotor system more susceptible to perturbations such as the interference of a concurrent action perception.

Neural coupling between the central nervous system and the periphery is essential for the neural control of movement. Corticomuscular coherence is a popular linear technique to assess synchronised oscillatory activity in the sensorimotor system. This oscillatory coupling originates from ascending somatosensory feedback and descending motor commands. However, corticomuscular coherence cannot separate this bidirectionality. Furthermore, the sensorimotor system is nonlinear, resulting in cross‐frequency coupling. Cross‐frequency oscillations cannot be assessed nor exploited by linear measures. Here, we emphasise the need of novel coupling measures, which provide directionality and acknowledge nonlinearity, to unveil neural coupling in the sensorimotor system. We highlight recent advances in the field and argue that assessing directionality and nonlinearity of neural coupling will break new ground in the study of the control of movement in healthy and neurologically impaired individuals.

A long-term debate concerns whether the sensorimotor coding carried out during transitive actions observation reflects the low-level movement implementation details or the movement goals. On the contrary, phonemes and emotional facial expressions are intransitive actions that do not fall into this debate. The investigation of phonemes discrimination has proven to be a good model to demonstrate that the sensorimotor system plays a role in understanding actions acoustically presented. In the present study, we adapted the experimental paradigms already used in phonemes discrimination during face posture manipulation, to the discrimination of emotional facial expressions. We submitted participants to a lower or to an upper face posture manipulation during the execution of a four alternative labelling task of pictures randomly taken from four morphed continua between two emotional facial expressions. The results showed that the implementation of low-level movement details influence the discrimination of ambiguous facial expressions differing for a specific involvement of those movement details. These findings indicate that facial expressions discrimination is a good model to test the role of the sensorimotor system in the perception of actions visually presented.