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efference copy

Hans Straka, Boris P Chagnaud
During head/body movements, gaze stability is ensured by transformation of motion-related sensory signals into respective motor commands. Passively induced motion in all vertebrates including amphibians evokes a robust vestibulo-ocular reflex, suggesting an equally important role of this motor reaction during actively induced motion. However, during self-induced movements including locomotion, motor efference copies offer a convenient additional substrate for counteracting retinal image displacements. During such locomotor activity in Xenopus laevis tadpoles, spinal central pattern generator-derived efference copies elicit spatio-temporally specific eye movements, which are functionally appropriate to offset swimming-related retinal image displacements...
March 7, 2017: Journal of Neurology
Sanneke Don, Margot De Kooning, Lennard Voogt, Kelly Ickmans, Liesbeth Daenen, Jo Nijs
Study Design Controlled laboratory study. Background Chronic whiplash-associated disorder (WAD) is an important health issue associated with poor recovery outcomes. Sensorimotor incongruence (SMI), defined as a mismatch between the efference copy in the brain and afferent sensory feedback from the body, is proposed as a possible underlying cause of chronic pain. Objectives To determine whether SMI causes sensory disturbances or pain in people with chronic WAD and healthy controls. Methods Sixty-four participants (30 with chronic WAD and 34 healthy controls) participated in a visual feedback experiment involving the neck and a bimanual coordination experiment involving the arms...
March 2017: Journal of Orthopaedic and Sports Physical Therapy
Reza Shadmehr
In generating a point to point movement, the brain does more than produce the transient commands needed to move the body part; it also produces the sustained commands that are needed to hold the body part at its destination. In the oculomotor system, these functions are mapped onto two distinct circuits: a pre-motor circuit that specializes in generating the transient activity that displaces the eyes, and a "neural integrator" that transforms that transient input into sustained activity that holds the eyes...
January 4, 2017: Journal of Neurophysiology
Norimichi Kitagawa, Masaharu Kato, Makio Kashino
When we actively interact with the environment, it is crucial that we perceive a precise temporal relationship between our own actions and sensory effects to guide our body movements. Thus, we hypothesized that voluntary movements improve perceptual sensitivity to the temporal disparity between auditory and movement-related somatosensory events compared to when they are delivered passively to sensory receptors. In the voluntary condition, participants voluntarily tapped a button, and a noise burst was presented at various onset asynchronies relative to the button press...
2016: Frontiers in Integrative Neuroscience
Francisco Branoner, Boris P Chagnaud, Hans Straka
Vestibulo-ocular reflexes (VOR) ensure gaze stability during locomotion and passively induced head/body movements. In precocial vertebrates such as amphibians, vestibular reflexes are required very early at the onset of locomotor activity. While the formation of inner ears and the assembly of sensory-motor pathways is largely completed soon after hatching, angular and translational/tilt VOR display differential functional onsets and mature with different time courses. Otolith-derived eye movements appear immediately after hatching, whereas the appearance and progressive amelioration of semicircular canal-evoked eye movements is delayed and dependent on the acquisition of sufficiently large semicircular canal diameters...
2016: Frontiers in Neural Circuits
He Cui
While remarkable progress has been made in brain-machine interfaces (BMIs) over the past two decades, it is still difficult to utilize neural signals to drive artificial actuators to produce predictive movements in response to dynamic stimuli. In contrast to naturalistic limb movements largely based on forward planning, brain-controlled neuroprosthetics mainly rely on feedback without prior trajectory formation. As an important sensorimotor interface integrating multisensory inputs and efference copy, the posterior parietal cortex (PPC) might play a proactive role in predictive motor control...
2016: Frontiers in Integrative Neuroscience
Yuval Porat, Ehud Zohary
Visual sensitivity is markedly reduced during an eye movement. Peri-saccadic vision is also characterized by a mislocalization of the briefly presented stimulus closer to the saccadic target. These features are commonly viewed as obligatory elements of peri-saccadic vision. However, practice improves performance in many perceptual tasks performed at threshold conditions. We wondered if this could also be the case with peri-saccadic perception. To test this, we used a paradigm in which subjects reported the orientation (or location) of an ellipse briefly presented during a saccade...
November 15, 2016: Proceedings of the National Academy of Sciences of the United States of America
Clare E Palmer, Marco Davare, James M Kilner
Sensory attenuation, the top-down filtering or gating of afferent information, has been extensively studied in two fields: physiological and perceptual. Physiological sensory attenuation is represented as a decrease in the amplitude of the primary and secondary components of the somatosensory evoked potential (SEP) before and during movement. Perceptual sensory attenuation, described using the analogy of a persons' inability to tickle oneself, is a reduction in the perception of the afferent input of a self-produced tactile sensation due to the central cancellation of the reafferent signal by the efference copy of the motor command to produce the action...
October 19, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Lorenza Capantini, Arndt von Twickel, Brita Robertson, Sten Grillner
In vertebrates, the pretectum and optic tectum (superior colliculus in mammals) are visuomotor areas that process sensory information and shape motor responses. Whereas the tectum has been investigated in great detail, the pretectum has received far less attention. The present study provides a detailed analysis of the connectivity and neuronal properties of lamprey pretectal cells. The pretectum can be subdivided roughly into three areas based on cellular location and projection pattern: superficial, central, and periventricular...
August 25, 2016: Journal of Comparative Neurology
Delphine Lévy-Bencheton, Aarlenne Zein Khan, Denis Pélisson, Caroline Tilikete, Laure Pisella
It is relatively easy to adapt visually-guided saccades because the visual vector and the saccade vector match. The retinal error at the saccade landing position is compared to the prediction error, based on target location and efference copy. If these errors do not match, planning processes at the level(s) of the visual and/or motor vector processing are assumed to be inaccurate and the saccadic response is adjusted. In the case of a sequence of two saccades, the final error can be attributed to the last saccade vector or to the entire saccadic displacement...
2016: Frontiers in Human Neuroscience
Pierre Berthet, Mikael Lindahl, Philip J Tully, Jeanette Hellgren-Kotaleski, Anders Lansner
The brain enables animals to behaviorally adapt in order to survive in a complex and dynamic environment, but how reward-oriented behaviors are achieved and computed by its underlying neural circuitry is an open question. To address this concern, we have developed a spiking model of the basal ganglia (BG) that learns to dis-inhibit the action leading to a reward despite ongoing changes in the reward schedule. The architecture of the network features the two pathways commonly described in BG, the direct (denoted D1) and the indirect (denoted D2) pathway, as well as a loop involving striatum and the dopaminergic system...
2016: Frontiers in Neural Circuits
Marc Benazet, François Thénault, Kevin Whittingstall, Pierre-Michel Bernier
It is well established that the cortical processing of somatosensory and auditory signals is attenuated when they result from self-generated actions compared with external events. This phenomenon is thought to result from an efference copy of motor commands used to predict the sensory consequences of an action through a forward model. The present work examined whether attenuation also takes place for visual reafferent signals from the moving limb during voluntary reaching movements. To address this issue, EEG activity was recorded in a condition in which visual feedback of the hand was provided in real time and compared with a condition in which it was presented with a 150-ms delay, thus creating a mismatch between the predicted and actual visual consequences of the movement...
October 1, 2016: Journal of Neurophysiology
Jack De Havas, Arko Ghosh, Hiroaki Gomi, Patrick Haggard
The capacity to inhibit actions is central to voluntary motor control. However, the control mechanisms and subjective experience involved in voluntarily stopping an involuntary movement remain poorly understood. Here we examined, in humans, the voluntary inhibition of the Kohnstamm phenomenon, in which sustained voluntary contraction of shoulder abductors is followed by involuntary arm raising. Participants were instructed to stop the involuntary movement, hold the arm in a constant position, and 'release' the inhibition after ∼2s...
October 2016: Cognition
Anatol G Feldman
Although action and perception are different behaviors, they are likely to be interrelated, as implied by the notions of perception-action coupling and active sensing. Traditionally, it has been assumed that the nervous system directly preprograms motor commands required for actions and uses a copy of them called efference copy (EC) to also influence our senses. This review offers a critical analysis of the EC concept by identifying its limitations. An alternative to the EC concept is based on the experimentally confirmed notion that sensory signals from receptors are perceived relative to referent signals specified by the brain...
September 1, 2016: Journal of Neurophysiology
Daria Genzel, Uwe Firzlaff, Lutz Wiegrebe, Paul R MacNeilage
Humans localize sounds by comparing inputs across the two ears, resulting in a head-centered representation of sound-source position. When the head moves, information about head movement must be combined with the head-centered estimate to correctly update the world-centered sound-source position. Spatial updating has been extensively studied in the visual system, but less is known about how head movement signals interact with binaural information during auditory spatial updating. In the current experiments, listeners compared the world-centered azimuthal position of two sound sources presented before and after a head rotation that depended on condition...
August 1, 2016: Journal of Neurophysiology
Carolyn J Perry, Prakash Amarasooriya, Mazyar Fallah
Feedback within the oculomotor system improves visual processing at eye movement end points, also termed a visual grasp. We do not just view the world around us however, we also reach out and grab things with our hands. A growing body of literature suggests that visual processing in near-hand space is altered. The control systems for moving either the eyes or the hands rely on parallel networks of fronto-parietal regions, which have feedback connections to visual areas. Since the oculomotor system effects on visual processing occur through feedback, both through the motor plan and the motor efference copy, a parallel system where reaching and/or grasping motor-related activity also affects visual processing is likely...
2016: Frontiers in Computational Neuroscience
Géraldine von Uckermann, François M Lambert, Denis Combes, Hans Straka, John Simmers
During swimming in the amphibian ITALIC! Xenopus laevis, efference copies of rhythmic locomotor commands produced by the spinal central pattern generator (CPG) can drive extraocular motor output appropriate for producing image-stabilizing eye movements to offset the disruptive effects of self-motion. During metamorphosis, ITALIC! X. laevisremodels its locomotor strategy from larval tail-based undulatory movements to bilaterally synchronous hindlimb kicking in the adult. This change in propulsive mode results in head/body motion with entirely different dynamics, necessitating a concomitant switch in compensatory ocular movements from conjugate left-right rotations to non-conjugate convergence during the linear forward acceleration produced during each kick cycle...
April 15, 2016: Journal of Experimental Biology
S Murray Sherman
Several challenges to current views of thalamocortical processing are offered here. Glutamatergic pathways in thalamus and cortex are divided into two distinct classes: driver and modulator. We suggest that driver inputs are the main conduits of information and that modulator inputs modify how driver inputs are processed. Different driver sources reveal two types of thalamic relays: first order relays receive subcortical driver input (for example, retinal input to the lateral geniculate nucleus), whereas higher order relays (for example, pulvinar) receive driver input from layer 5 of cortex and participate in cortico-thalamo-cortical (or transthalamic) circuits...
April 2016: Nature Neuroscience
Jeong-Yoon Choi, Ji-Soo Kim
Non-vestibular sensorimotor signals modulate the vestibular nucleus neuron to achieve current behavioral goals, and may generate or modulate nystagmus. In central lesions affecting the vestibular nuclei, non-vestibular signals such as mastication or swallowing may induce nystagmus. However, the influence of non-vestibular signals on these types of nystagmus has not been investigated in a systematic way and the underlying mechanisms of the modulation are poorly understood. In this study, several non-vestibular sensorimotor stimuli were applied to evaluate the patterns of nystagmus modulation in a patient with suspected rhombencephalitis or imaging negative small infarction, probably involving the left dorsolateral medulla...
April 2016: Journal of Neurology
Zhenyu Gao, Martina Proietti-Onori, Zhanmin Lin, Michiel M Ten Brinke, Henk-Jan Boele, Jan-Willem Potters, Tom J H Ruigrok, Freek E Hoebeek, Chris I De Zeeuw
Closed-loop circuitries between cortical and subcortical regions can facilitate precision of output patterns, but the role of such networks in the cerebellum remains to be elucidated. Here, we characterize the role of internal feedback from the cerebellar nuclei to the cerebellar cortex in classical eyeblink conditioning. We find that excitatory output neurons in the interposed nucleus provide efference-copy signals via mossy fibers to the cerebellar cortical zones that belong to the same module, triggering monosynaptic responses in granule and Golgi cells and indirectly inhibiting Purkinje cells...
February 3, 2016: Neuron
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