scholarly journals Signs of Timing in Motor Cortex During Movement Preparation and Cue Anticipation

2014 ◽  
pp. 121-142 ◽  
Author(s):  
Bjørg Elisabeth Kilavik ◽  
Joachim Confais ◽  
Alexa Riehle
Keyword(s):  
Motor Cortex ◽  
Movement Preparation

scholarly journals Dissociation between sustained single-neuron spiking and transient β-LFP oscillations in primate motor cortex

2017 ◽  
Vol 117 (4) ◽  
pp. 1524-1543 ◽  
Author(s):  
Michael E. Rule ◽  
Carlos E. Vargas-Irwin ◽  
John P. Donoghue ◽  
Wilson Truccolo
Keyword(s):  
Steady State ◽  
Motor Cortex ◽  
Local Field ◽  
Single Neuron ◽  
Field Potential ◽  
Movement Preparation ◽  
Phase Coupling ◽  
Firing Rates ◽  
Sources Of Variation ◽  
Transient Events

Determining the relationship between single-neuron spiking and transient (20 Hz) β-local field potential (β-LFP) oscillations is an important step for understanding the role of these oscillations in motor cortex. We show that whereas motor cortex firing rates and beta spiking rhythmicity remain sustained during steady-state movement preparation periods, β-LFP oscillations emerge, in contrast, as short transient events. Single-neuron mean firing rates within and outside transient β-LFP events showed no differences, and no consistent correlation was found between the beta oscillation amplitude and firing rates, as was the case for movement- and visual cue-related β-LFP suppression. Importantly, well-isolated single units featuring beta-rhythmic spiking (43%, 125/292) showed no apparent or only weak phase coupling with the transient β-LFP oscillations. Similar results were obtained for the population spiking. These findings were common in triple microelectrode array recordings from primary motor (M1), ventral (PMv), and dorsal premotor (PMd) cortices in nonhuman primates during movement preparation. Although beta spiking rhythmicity indicates strong membrane potential fluctuations in the beta band, it does not imply strong phase coupling with β-LFP oscillations. The observed dissociation points to two different sources of variation in motor cortex β-LFPs: one that impacts single-neuron spiking dynamics and another related to the generation of mesoscopic β-LFP signals. Furthermore, our findings indicate that rhythmic spiking and diverse neuronal firing rates, which encode planned actions during movement preparation, may naturally limit the ability of different neuronal populations to strongly phase-couple to a single dominant oscillation frequency, leading to the observed spiking and β-LFP dissociation. NEW & NOTEWORTHY We show that whereas motor cortex spiking rates and beta (~20 Hz) spiking rhythmicity remain sustained during steady-state movement preparation periods, β-local field potential (β-LFP) oscillations emerge, in contrast, as transient events. Furthermore, the β-LFP phase at which neurons spike drifts: phase coupling is typically weak or absent. This dissociation points to two sources of variation in the level of motor cortex beta: one that impacts single-neuron spiking and another related to the generation of measured mesoscopic β-LFPs.

scholarly journals Selective Suppression of Local Circuits during Movement Preparation in the Mouse Motor Cortex

Cell Reports ◽  
2017 ◽  
Vol 18 (11) ◽  
pp. 2676-2686 ◽  
Author(s):  
Masashi Hasegawa ◽  
Kei Majima ◽  
Takahide Itokazu ◽  
Takakuni Maki ◽  
Urban-Raphael Albrecht ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Movement Preparation ◽  
Selective Suppression ◽  
Local Circuits

Automatic activation in the human primary motor cortex synchronized with movement preparation

1999 ◽  
Vol 8 (3) ◽  
pp. 229-239 ◽  
Author(s):  
Hiroshi Endo ◽  
Tomohiro Kizuka ◽  
Tadashi Masuda ◽  
Tsunehiro Takeda
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Movement Preparation ◽  
Automatic Activation

scholarly journals Behavioral context determines network state and variability dynamics in monkey motor cortex

2017 ◽  
Author(s):  
Alexa Riehle ◽  
Thomas Brochier ◽  
Martin Paul Nawrot ◽  
Sonja Grün
Keyword(s):  
Motor Cortex ◽  
Computational Models ◽  
Phase Locking ◽  
Motor Task ◽  
Field Potential ◽  
Fano Factor ◽  
Movement Preparation ◽  
Contextual Dependence ◽  
Monkey Motor Cortex ◽  
Spiking Activity

AbstractVariability of spiking activity is ubiquitous throughout the brain but little is known about its contextual dependence. Trial-to-trial spike count variability, estimated by the Fano Factor (FF), and within-trial spike time irregularity, quantified by the local coefficient of variation (CV2), reflect variability on long and short time scales, respectively. We co-analyzed FF and CV2 in monkey motor cortex comparing two behavioral contexts, movement preparation (wait) and execution (movement). We find that FF significantly decreases from wait to movement, while CV2 increases. The more regular firing (low CV2) during wait is related to an increased power of local field potential beta oscillations and phase locking of spikes to these oscillations. In renewal processes, a widely used model for spiking activity under stationary input conditions, both measures are related as FF≈CV2. This expectation was met during movement, but not during wait where FF≫CV22. We conclude that during movement preparation, ongoing brain processes result in changing network states and thus in high trial-to-trial variability (high FF). During movement execution, the network is recruited for performing the stereotyped motor task, resulting in reliable single neuron output. We discuss our results in the light of recent computational models that generate non-stationary network conditions.

scholarly journals The primary motor cortex is critical for the retention of implicit sensorimotor adaptation

2016 ◽  
Author(s):  
Li-Ann Leow ◽  
Welber Marinovic ◽  
Timothy J Carroll ◽  
Stephan Riek
Keyword(s):  
Motor Cortex ◽  
Implicit Learning ◽  
Visual Feedback ◽  
Primary Motor Cortex ◽  
Single Pulse ◽  
Sensorimotor Adaptation ◽  
List Type ◽  
Movement Preparation ◽  
Implicit Processes

AbstractSensorimotor adaptation, or adaptation of movements to external perturbations, is thought to involve the primary motor cortex (M1). In addition to implicit error-driven remapping, explicit re-aiming strategies also contribute to sensorimotor adaptation. However, no studies to date have examined the role of M1 in implicit learning in isolation from explicit strategies. Because the application of explicit strategies requires time, it is possible to emphasise implicit learning by controlling the time available to prepare movement. Here, we examined the role of M1’s role in implicit adaptation to rotated visual feedback whilst suppressing the use of explicit re-aiming strategies by limiting movement preparation times to less than 350ms. Perturbing M1 activity via single-pulse TMS during adaptation to a 30 ° rotation of visual feedback did not alter the rate or extent of error compensation, but elicited poorer retention in post-adaptation trials with no perturbation. This work shows that M1 is critical in the retention of new visuomotor maps as a result of implicit adaptation to a perturbation in sensory feedback when strategic error correction processes are suppressed.HighlightsAdaptation of movements to perturbations occurs through explicit and implicit processes.Here, explicit strategies were suppressed by shortening movement preparation time.Perturbing motor cortex (M1) with TMS selectively impaired retention but not acquisition of sensorimotor adaptation.M1 plays a crucial role in retention of sensorimotor adaptation obtained via implicit learning.

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