scholarly journals Prior Knowledge of Target Direction and Intended Movement Selection Improves Indirect Reaching Movement Decoding

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Hongbao Li ◽  
Yaoyao Hao ◽  
Shaomin Zhang ◽  
Yiwen Wang ◽  
Weidong Chen ◽  
...  
Keyword(s):  
Prior Knowledge ◽  
Premotor Cortex ◽  
Movement Planning ◽  
Avoidance Task ◽  
Movement Trajectory ◽  
Reaching Movement ◽  
Target Direction ◽  
Neural Activities ◽  
Direction Information ◽  
Movement Selection

Objective.Previous studies have demonstrated that target direction information presented by the dorsal premotor cortex (PMd) during movement planning could be incorporated into neural decoder for achieving better decoding performance. It is still unknown whether the neural decoder combined with only target direction could work in more complex tasks where obstacles impeded direct reaching paths.Methods.In this study, spike activities were collected from the PMd of two monkeys when performing a delayed obstacle-avoidance task. We examined how target direction and intended movement selection were encoded in neuron population activities of the PMd during movement planning. The decoding performances of movement trajectory were compared for three neural decoders with no prior knowledge, or only target direction, or both target direction and intended movement selection integrated into a mixture of trajectory model (MTM).Results.We found that not only target direction but also intended movement selection was presented in neural activities of the PMd during movement planning. It was further confirmed by quantitative analysis. Combined with prior knowledge, the trajectory decoder achieved the best performance among three decoders.Conclusion.Recruiting prior knowledge about target direction and intended movement selection extracted from the PMd could enhance the decoding performance of hand trajectory in indirect reaching movement.

Dorsal Premotor Cortex and Conditional Movement Selection: A PET Functional Mapping Study

1998 ◽  
Vol 79 (2) ◽  
pp. 1092-1097 ◽  
Author(s):  
S. T. Grafton ◽  
A. H. Fagg ◽  
M. A. Arbib
Keyword(s):  
Average Rate ◽  
Premotor Cortex ◽  
Random Order ◽  
Normal Subjects ◽  
Functional Mapping ◽  
Dorsal Premotor Cortex ◽  
Mapping Study ◽  
Large Area ◽  
Related Activity ◽  
Movement Selection

Grafton, S. T., A. H. Fagg, and M. A. Arbib. Dorsal premotor cortex and conditional movement selection: a PET functional mapping study. J. Neurophysiol. 79: 1092–1097, 1998. Positron emission tomography (PET) brain mapping was used to investigate whether or not human dorsal premotor cortex is involved in selecting motor acts based on arbitrary visual stimuli. Normal subjects performed four movement selection tasks. A manipulandum with three graspable stations was used. An imperative visual cue (LEDs illuminated in random order) indicated which station to grasp next with no instructional delay period. In a power task, a large aperture power grip was used for all trials, irrespective of the LED color. In a precision task, a pincer grasp of thumb and index finger was used. In a conditional task, the type of grasp (power or precision) was randomly determined by LED color. Comparison of the conditional selection task versus the average of the power and precision tasks revealed increased blood flow in left dorsal premotor cortex and superior parietal lobule. The average rate of producing the different grasp types and transport to the manipulandum stations was equivalent across this comparison, minimizing the contribution of movement attributes such as planning the individual movements (as distinct from planning associated with use of instructional stimuli), kinematics, or direction of target or limb movement. A comparison of all three movement tasks versus a rest task identified movement related activity involving a large area of central, precentral and postcentral cortex. In the region of the precentral sulcus movement related activity was located immediately caudal to the area activated during selection. The results establish a role for human dorsal premotor cortex and superior parietal cortex in selecting stimulus guided movements and suggest functional segregation within dorsal premotor cortex.

scholarly journals Optimal Stochastic Control Problem for General Linear Dynamical Systems in Neuroscience

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Yan Chen ◽  
Yingchun Deng ◽  
Shengjie Yue ◽  
Chao Deng
Keyword(s):  
Stochastic Control ◽  
Optimal Trajectory ◽  
Control Method ◽  
Dimensional Space ◽  
Target Position ◽  
Movement Trajectory ◽  
Linear Dynamical Systems ◽  
Reaching Movement ◽  
Optimal Velocity ◽  
Straight Line

This paper considers a d-dimensional stochastic optimization problem in neuroscience. Suppose the arm’s movement trajectory is modeled by high-order linear stochastic differential dynamic system in d-dimensional space, the optimal trajectory, velocity, and variance are explicitly obtained by using stochastic control method, which allows us to analytically establish exact relationships between various quantities. Moreover, the optimal trajectory is almost a straight line for a reaching movement; the optimal velocity bell-shaped and the optimal variance are consistent with the experimental Fitts law; that is, the longer the time of a reaching movement, the higher the accuracy of arriving at the target position, and the results can be directly applied to designing a reaching movement performed by a robotic arm in a more general environment.

Hand-held tools with complex kinematics are efficiently incorporated into movement planning and online control

2012 ◽  
Vol 108 (7) ◽  
pp. 1954-1964 ◽  
Author(s):  
Lee A. Baugh ◽  
Erica Hoe ◽  
J. Randall Flanagan
Keyword(s):  
Online Control ◽  
Movement Planning ◽  
Control Mechanisms ◽  
Movement Initiation ◽  
Reaching Movement ◽  
Hand Motion ◽  
Reversal Condition ◽  
End Point ◽  
Point Motion ◽  
Time Required

Certain hand-held tools alter the mapping between hand motion and motion of the tool end point that must be controlled in order to perform a task. For example, when using a pool cue, the motion of the cue tip is reversed relative to the hand. Previous studies have shown that the time required to initiate a reaching movement (Fernandez-Ruiz J, Wong W, Armstrong IT, Flanagan JR. Behav Brain Res 219: 8–14, 2011), or correct an ongoing reaching movement (Gritsenko V, Kalaska JF. J Neurophysiol 104: 3084–3104, 2010), is prolonged when the mapping between hand motion and motion of a cursor controlled by the hand is reversed. Here we show that these time costs can be significantly reduced when the reversal is instantiated by a virtual hand-held tool. Participants grasped the near end of a virtual tool, consisting of a rod connecting two circles, and moved the end point to displayed targets. In the reversal condition, the rod translated through, and rotated about, a pivot point such that there was a left-right reversal between hand and end point motion. In the nonreversal control, the tool translated with the hand. As expected, when only the two circles were presented, movement initiation and correction times were much longer in the reversal condition. However, when full vision of the tool was provided, the reaction time cost was almost eliminated. These results indicate that tools with complex kinematics can be efficiently incorporated into sensorimotor control mechanisms used in movement planning and online control.

scholarly journals Online modification of goal-directed control in human reaching movements

2021 ◽  
Author(s):  
Antoine De Comite ◽  
Frédéric Crevecoeur ◽  
Philippe Lefèvre
Keyword(s):  
Control Strategies ◽  
Control Policy ◽  
Visual Display ◽  
Surface Emg ◽  
Movement Planning ◽  
Reaching Movements ◽  
Reaching Movement ◽  
Flexible Control ◽  
Task Goal ◽  
Sudden Appearance

Humans are able to perform very sophisticated reaching movements in a myriad of contexts based on flexible control strategies influenced by the task goal and environmental constraints such as obstacles. However, it remains unknown whether these control strategies can be adjusted online. The objective of this study was to determine whether the factors which determine control strategies during planning also modify the execution of an ongoing movement following sudden changes in task demand. More precisely, we investigated whether, and at which latency, feedback responses to perturbation loads followed the change in the structure of the goal target or environment. We changed the target width (square or rectangle) to alter the task redundancy, or the presence of obstacles to induce different constraints on the reach path, and assessed based on surface EMG recordings when the change in visual display altered the feedback response to mechanical perturbations. Task-related EMG responses were detected within 150 ms of a change in target shape. Considering visuomotor delays of ~ 100 ms, these results suggest that it takes 50 ms to change control policy within a trial. An additional 30 ms delay was observed when the change in context involved sudden appearance or disappearance of obstacles. Overall, our results demonstrate that the control policy within a reaching movement is not static: contextual factors which influence movement planning also influence movement execution at surprisingly short latencies. Moreover, the additional 30 ms associated with obstacles suggest that these two types of changes may be mediated via distinct processes.

Development of Sensor-Based Navigation for Mobile Robots Using Target Direction Sensor

1999 ◽  
Vol 11 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Motoji Yamamoto ◽  
◽  
Nobuhiro Ushimi ◽  
Akira Mohri
Keyword(s):  
Measurement Error ◽  
Mobile Robot ◽  
Motion Planning ◽  
Mobile Robots ◽  
Navigation System ◽  
Location Information ◽  
Work Space ◽  
Target Direction ◽  
Navigation Algorithm ◽  
Direction Information

Sensor-based navigation used a target direction sensor for mobile robots among unknown obstacles in work space is discussed. The advantage of target direction information is robustness of measurement error for online navigation, compared to robot location information. Convergence of navigation using target direction information is discussed. An actual sensor system using two CdS sensors to measure target direction is proposed. Using target direction information, we present a new sensor based navigation algorithm in unknown obstacle environment. The navigation algorithm is based on target direction information, unlike sensor-based motion planning algorithms based on mobile robot location information. Using a sensor-based navigation system, we conducted a navigation experiment and simulations in unknown obstacle environment.

scholarly journals The human motor system alters its reaching movement plan for task-irrelevant, positional forces

2015 ◽  
Vol 113 (7) ◽  
pp. 2137-2149 ◽  
Author(s):  
Joshua G. A. Cashaback ◽  
Heather R. McGregor ◽  
Paul L. Gribble
Keyword(s):  
Uncontrolled Manifold ◽  
Movement Trajectory ◽  
Uncontrolled Manifold Hypothesis ◽  
Natural Behavior ◽  
Reaching Movement ◽  
Task Success ◽  
Human Motor ◽  
Hypothesis State ◽  
Task Irrelevant ◽  
Active Exploration

The minimum intervention principle and the uncontrolled manifold hypothesis state that our nervous system only responds to force perturbations and sensorimotor noise if they affect task success. This idea has been tested in muscle and joint coordinate frames and more recently using workspace redundancy (e.g., reaching to large targets). However, reaching studies typically involve spatial and or temporal constraints. Constrained reaches represent a small proportion of movements we perform daily and may limit the emergence of natural behavior. Using more relaxed constraints, we conducted two reaching experiments to test the hypothesis that humans respond to task-relevant forces and ignore task-irrelevant forces. We found that participants responded to both task-relevant and -irrelevant forces. Interestingly, participants experiencing a task-irrelevant force, which simply pushed them into a different area of a large target and had no bearing on task success, changed their movement trajectory prior to being perturbed. These movement trajectory changes did not counteract the task-irrelevant perturbations, as shown in previous research, but rather were made into new areas of the workspace. A possible explanation for this behavior change is that participants were engaging in active exploration. Our data have implications for current models and theories on the control of biological motion.

scholarly journals Online modification of goal-directed control in human reaching movements

2020 ◽  
Author(s):  
Antoine De Comite ◽  
Frédéric Crevecoeur ◽  
Philippe Lefèvre
Keyword(s):  
Control Strategies ◽  
Control Policy ◽  
Visual Display ◽  
Movement Planning ◽  
Reaching Movements ◽  
Planning Stage ◽  
Reaching Movement ◽  
Flexible Control ◽  
Task Goal ◽  
Sudden Appearance

AbstractHumans are able to perform very sophisticated reaching movements in a myriad of contexts based on flexible control strategies influenced by the task goal and environmental constraints such as obstacles. However, it remains unknown whether these control strategies can be adjusted online. The objective of this study was to determine whether the factors which determine control strategies during planning also modify the execution of an ongoing movement following sudden changes in task demand. More precisely, we investigated whether, and at which latency, feedback responses to perturbation loads followed the change in the structure of the goal target or environment. We changed the target width (square or rectangle) to alter the task redundancy, or the presence of obstacles to induce different constraints on the reach path, and assessed based on surface recordings when the change in visual display altered the feedback response to mechanical perturbations. Task-related EMG responses were detected within 150 ms of a change in target shape. Considering visuomotor delays of ∼ 100 ms, these results suggest that it takes 50 ms to change control policy within a trial. An additional 30 ms delay was observed when the change in context involved sudden appearance or disappearance of obstacles. Overall, our results demonstrate that the control policy within a reaching movement is not static: contextual factors which influence movement planning also influence movement execution at surprisingly short latencies. Moreover, the additional 30 ms associated with obstacles suggest that these two types of changes may be mediated via distinct processes.New & NoteworthyThe present work demonstrates that the control strategies used to perform reaching movements are adjusted online when the structure of the target or the presence of obstacles are altered during movements. Thus, the properties of goal-directed reaching control are not simply selected during the planning stage of a movement prior to execution. Rather, they are dynamically and rapidly adjusted online, within ∼150ms, according to changes in environment.

scholarly journals Recurrent neural network models of multi-area computation underlying decision-making

2019 ◽  
Author(s):  
Michael Kleinman ◽  
Chandramouli Chandrasekaran ◽  
Jonathan C. Kao
Keyword(s):  
Premotor Cortex ◽  
Network Models ◽  
Brain Regions ◽  
Neural Systems ◽  
Neural Network Models ◽  
Orthogonal Direction ◽  
Brain Areas ◽  
Dynamical Mechanism ◽  
Decision Variables ◽  
Direction Information

AbstractCognition emerges from coordinated computations across multiple brain areas. However, elucidating these computations within and across brain regions is challenging because intra- and inter-area connectivity are typically unknown. To study coordinated computation, we trained multi-area recurrent neural networks (RNNs) to discriminate the dominant color of a checker-board and output decision variables reflecting a direction decision, a task previously used to investigate decision-related dynamics in dorsal premotor cortex (PMd) of monkeys. We found that multi-area RNNs, trained with neurophysiological connectivity constraints and Dale’s law, recapitulated decision-related dynamics observed in PMd. The RNN solved this task by a dynamical mechanism where the direction decision was computed and outputted, via precisely oriented dynamics, on an axis that was nearly orthogonal to checkerboard color inputs. This orthogonal direction information was preferentially propagated through alignment with inter-area connections; in contrast, color information was filtered. These results suggest that cortex uses modular computation to generate minimal sufficient representations of task information. Finally, we used multi-area RNNs to produce experimentally testable hypotheses for computations that occur within and across multiple brain areas, enabling new insights into distributed computation in neural systems.

Sign in / Sign up

Export Citation Format

Share Document