The nervous system controls the behavior of complex kinematically redundant biomechanical systems. How it computes appropriate commands to generate movements is unknown. Here we propose a model based on assumption that system: 1) processes static (e.g., gravitational) and dynamic inertial) forces separately; 2) calculates master progress toward goal according principles optimal feedback control; 3) uses size (effort) as an optimality criterion; 4) can specify movement duration from given...

Concept cells in the human hippocampus encode meaning conveyed by stimuli over their perceptual aspects. Here we investigate whether analogous macaque can form conceptual schemas of spatial environments. Each day, monkeys were presented with a familiar and novel virtual maze, sharing common schema but differing surface features (landmarks). In both environments, animals searched for hidden reward goal only defined relation to landmarks. With learning, many neurons developed firing map...

To elucidate how gaze informs the construction of mental space during wayfinding in visual species like primates, we jointly examined navigation behavior, exploration, and hippocampal activity as macaque monkeys searched a virtual reality maze for reward. Cells sensitive to place also responded one or more variables head direction, point gaze, task context. Many cells fired at sight (and anticipation) single landmark viewpoint- task-dependent manner, simultaneously encoding animal’s logical...

Previous studies have shown that human subjects can adapt to a new visuomotor relationship depends on the trajectory of arm. However, these not distinguished between hand- and joint-based learning models. We examined whether different endpoint kinematics are necessary obtain differential shift. The joint was varied by changing initial posture, while maintaining similar finger trajectory. After learning, maximum after-effects were found when movement began with posture used during exposure...

Significance The motor repertoire of infants is narrow. Yet newborns can accurately bring their hands toward mouth for self-feeding, thumb-sucking, or perioral exploration, thus showing fine coordinated movement synergies between the hand and mouth. Here, we show that these gestures high ethological value are selectively encoded in human brain represented as integrated primitives within precentral gyrus, a key region sensorimotor processing. These findings have major implications our...

Decoding neuronal information is important in neuroscience, both as a basic means to understand how activity related cerebral function and processing stage driving neuroprosthetic effectors. Here, we compare the readout performance of six commonly used classifiers at decoding two different variables encoded by spiking non-human primate frontal eye fields (FEF): spatial position visual cue, instructed orientation animal's attention. While first variable exogenously driven environment, second...

Explaining or predicting the behaviour of our conspecifics requires ability to infer intentions that motivate it. Such inferences are assumed rely on two types information: (1) sensory information conveyed by movement kinematics and (2) observer's prior expectations--acquired from past experience derived knowledge. However, respective contribution these sources is still controversial. This controversy stems in part fact "intention" an umbrella term may embrace various sub-types each being...

Speed/accuracy trade-off is a ubiquitous phenomenon in motor behaviour, which has been ascribed to the presence of signal-dependent noise (SDN) commands. Although this explanation can provide quantitative account many aspects variability, including Fitts' law, fact that law frequently violated, e.g. during acquisition new skills, remains unexplained. Here, we describe principled approach influence on variability results from interplay between sensory and execution noises an optimal...

Background: Impairment in initiating movements PD might be related to executive dysfunction associated with abnormal proactive inhibitory control, a pivotal mechanism consisting gating movement initiation uncertain contexts. Objective: Testing this hypothesis on the basis of direct neural-based evidence. Methods: Twelve patients antiparkinsonian medication and fifteen matched healthy controls performed simple reaction time task during event-related functional MRI scanning. Results: For all...

Proximal and distal muscles are different in size, maximum force, mechanical action, neuromuscular control. In the current study we explore perception of delayed stiffness when probing is executed using movement joints. We found a proximodistal gradient amount underestimation transition between with shoulder, elbow, wrist Moreover, there was similar optimal weighting estimation inverse compliance that predicted subjects. These gradients could not be ascribed to differences amplitude,...

<h3>Background:</h3> In patients with Parkinson's disease (PD), motor performance may be dramatically improved in urgent and stressful situations. <h3>Objective:</h3> The aim of this PET H₂¹⁵O study was to determine the changes brain activation pattern related unconscious increase speed observed context urgency PD. <h3>Methods:</h3> Eight right-handed PD, who had been off medication for at least 12 hours, without tremor, were enrolled. A reaching task right hand...

Coordinated movements result from descending commands transmitted by central motor systems to the muscles. Although resulting effect of has dimension a muscular force, it is unclear whether information concerns movement kinematics (e.g. position, velocity) or dynamics torque). To address this issue, we used an optimal control model production that calculates inputs motoneurons are appropriate drive articulated limb toward goal. The quantitatively accounted for kinematic, kinetic and...

Primary saccades undershoot their target. Corrective are then triggered by retinal postsaccadic information. We tested whether primary still when no visual information is available. Participants saccaded to five targets (10-34 degrees) that were either constantly illuminated (ON) or extinguished at saccade onset (OFF(Onset)). In OFF(Onset), few corrective observed. The saccadic gain increased over trials for the furthest (34 Terminal eye position after glissades microsaccades progressively...

Sensorimotor systems face complex and frequent discrepancies among spatial modalities, for example, growth, optical distortion, telemanipulation. Adaptive mechanisms must act continuously to restore perceptual-motor alignments necessary perception of a coherent world. Experimental manipulations that exposed participants localized showed adaptation is revealed by the acquisition constrained relation between entire modalities rather than associations individual exemplars within these...

Many neurons of the central nervous system are broadly tuned to some sensory or motor variables. This property allows one assign each neuron a preferred attribute (PA). The width tuning curves and distribution PAs in population given variable define collective behavior population. In this article, we study relationship nature curves, PAs, computational properties linear neuronal populations. We show that noise-resistant distributed algebraic processing learning can be implemented by cosine...