Populations of cortical neurons flexibly perform different functions; for the primary motor cortex (M1) this means a rich repertoire behaviors. We investigate flexibility M1 movement control by analyzing neural population activity during variety skilled wrist and reach-to-grasp tasks. compare across tasks modes that capture dominant covariance patterns each task. While task requires muscle single unit activity, we find unexpected similarities at level: structure is largely preserved...

Abstract Animals of the same species exhibit similar behaviours that are advantageously adapted to their body and environment. These shaped at level by selection pressures over evolutionary timescales. Yet, it remains unclear how these common behavioural adaptations emerge from idiosyncratic neural circuitry each individual. The overall organization circuits is preserved across individuals 1 because evolutionarily specified developmental programme 2–4 . Such circuit may constrain activity...

Abstract Animals use feedback to rapidly correct ongoing movements in the presence of a perturbation. Repeated exposure predictable perturbation leads behavioural adaptation that compensates for its effects. Here, we tested hypothesis all processes necessary motor may emerge as properties controller adaptively updates policy. We trained recurrent neural network control own output through an error-based signal, which allowed it counteract external perturbations. Implementing biologically...

The spiking activity of populations cortical neurons is well described by the dynamics a small number population-wide covariance patterns, whose activation we refer to as ‘latent dynamics’. These latent are largely driven same correlated synaptic currents across circuit that determine generation local field potentials (LFPs). Yet, relationship between and LFPs remains unexplored. Here, characterised this for three different regions primate sensorimotor cortex during reaching. correlation was...

There is rich variety in the activity of single neurons recorded during behaviour. Yet, these diverse neuron responses can be well described by relatively few patterns neural co-modulation. The study such low-dimensional structure population has provided important insights into how brain generates Virtually all studies have used linear dimensionality reduction techniques to estimate population-wide co-modulation patterns, constraining them a flat “neural manifold”. Here, we hypothesised that...

This paper presents a two stage algorithm for real-time estimation of instantaneous tremor parameters from gyroscope recordings. Gyroscopes possess the advantage providing directly joint rotational speed, overcoming limitations traditional recording based on accelerometers. The proposed first extracts patterns raw angular data, and afterwards estimates its amplitude frequency. Real-time separation voluntary tremorous motion relies their different frequency contents, whereas modelling is an...

This paper presents the fully automatic identification of motor unit spike trains from high-density surface electromyograms (EMG) in pathological tremor. First, a mathematical derivation is provided to theoretically prove possibility decomposing noise-free EMG signals into with high correlation, which are typical tremor contractions. Further, proposed decomposition method tested on simulated different levels noise and experimental 14 tremor-affected patients. In case central frequency...

Pathological tremor is the most prevalent movement disorder. Current treatments do not attain a significant reduction in large proportion of patients, which makes major cause loss quality life. For instance, according to some estimates, 65% those suffering from upper limb report serious difficulties during daily living. Therefore, novel forms for management are required. Since muscles intrinsically behave as low pass filter, and frequency above that volitional movements, authors envisioned...

The nervous system evolved to enable navigation throughout the environment in pursuit of resources. Evolutionarily newer structures allowed increasingly complex adaptations but necessarily added redundancy. A dominant view movement neuroscientists is that there a one-to-one mapping between brain region and function. However, recent experimental data hard reconcile with most conservative interpretation this framework, suggesting degree functional redundancy during performance well-learned,...

Abstract Animals can quickly adapt learned movements to external perturbations, and their existing motor repertoire likely influences ease of adaptation. Long-term learning causes lasting changes in neural connectivity, which shapes the activity patterns that be produced during Here, we examined how a population’s patterns, acquired through de novo learning, affect subsequent adaptation by modeling cortical population dynamics with recurrent networks. We trained networks on different...

Compliant mechanisms are rapidly gaining importance, yet their design remains challenging. A great variety of methods being developed as it is reported in a growing stream publications. However, so far no review this body literature available. This paper provides comprehensive and conceptual overview the main notions behind most relevant for compliant mechanisms. Rigid-Body-Replacement including Pseudo-Rigid-Body model FACT approach covered, well Building Block approaches. In addition an...

Tremor in essential tremor (ET) is generated by pathological oscillations at 4–12 Hz, likely originating cerebello-thalamo-cortical pathways. However, the way which represented output of spinal cord circuitries largely unknown because difficulties identifying behavior individual motor units from tremulous muscles. By using novel methods for decomposition multichannel surface EMG, we provide a systematic analysis discharge properties nine ET patients, with concurrent recordings EEG activity....

The pathophysiology of essential tremor (ET), the most common movement disorder, is not fully understood. We investigated which factors determine variability in phase difference between neural drives to antagonist muscles, a long-standing observation yet unexplained. used computational model simulate effects different levels voluntary and tremulous synaptic input antagonistic motoneuron pools on tremor. compared these simulations data from 11 human ET patients. In both analyses, drive muscle...

Abstract Animals rapidly adapt their movements to external perturbations, a process paralleled by changes in neural activity the motor cortex. Experimental studies suggest that these originate from altered inputs (H input ) rather than local connectivity ), as covariance is largely preserved during adaptation. Since measuring synaptic vivo remains very challenging, we used modular recurrent network qualitatively test this interpretation. As expected, H resulted small and covariance....