Dynamical Organization of Directional Tuning in the Primate Premotor and Primary Motor Cortex

2003 ◽  
Vol 89 (2) ◽  
pp. 1136-1142 ◽  
Author(s):  
Yoram Ben-Shaul ◽  
Eran Stark ◽  
Itay Asher ◽  
Rotem Drori ◽  
Zoltan Nadasdy ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Hand Movement ◽  
Movement Direction ◽  
Cortical Surface ◽  
Preferred Direction ◽  
Preparation Period ◽  
Direction Of Movement ◽  
The Mean ◽  
Movement Parameters

Although previous studies have shown that activity of neurons in the motor cortex is related to various movement parameters, including the direction of movement, the spatial pattern by which these parameters are represented is still unresolved. The current work was designed to study the pattern of representation of the preferred direction (PD) of hand movement over the cortical surface. By studying pairwise PD differences, and by applying a novel implementation of the circular variance during preparation and movement periods in the context of a center-out task, we demonstrate a nonrandom distribution of PDs over the premotor and motor cortical surface of two monkeys. Our analysis shows that, whereas PDs of units recorded by nonadjacent electrodes are not more similar than expected by chance, PDs of units recorded by adjacent electrodes are. PDs of units recorded by a single electrode display the greatest similarity. Comparison of PD distributions during preparation and movement reveals that PDs of nearby units tend to be more similar during the preparation period. However, even for pairs of units recorded by a single electrode, the mean PD difference is typically large (45° and 75° during preparation and movement, respectively), so that a strictly modular representation of hand movement direction over the cortical surface is not supported by our data.

Neuronal specification of direction and distance during reaching movements in the superior precentral premotor area and primary motor cortex of monkeys

1993 ◽  
Vol 70 (5) ◽  
pp. 2097-2116 ◽  
Author(s):  
Q. G. Fu ◽  
J. I. Suarez ◽  
T. J. Ebner
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Arm Movement ◽  
Movement Direction ◽  
Target Movement ◽  
Reaching Task ◽  
Premotor Area ◽  
Preferred Direction ◽  
The Mean ◽  
Time Periods

1. Single-unit neuronal activity was recorded in the primary motor and superior precentral premotor areas of two rhesus monkeys during an arm reaching task. The task involved moving a cursor displayed on a video terminal using a draftsman's arm-type manipulandum. From a centrally located start box the animal was required to move to 1 of 48 target boxes at eight different directions (0-360 degrees in 45 degrees intervals) and six distances (1.4-5.4 cm in 0.8-cm increments). Both direction and distance for the upcoming movement were unpredictable. 2. The activity of 197 arm movement-related cells was recorded and evaluated for each of the 48 targets. Histological examination showed the cells to be primarily in the primary motor cortex or in the premotor area around the superior precentral sulcus. Each cell's discharge was aligned on movement onset and averaged over five trials for each target. Movement kinematics including hand path velocity were also determined. The task time was divided into three epochs, a premovement period (PT), a movement period (MT), and total time (TT = PT+MT). For each epoch the average firing was correlated with the direction and distance of the movement using various regression procedures. 3. An analysis of variance (ANOVA) showed that the majority of neurons were modulated significantly by movement direction in each of the three time periods, PT (73.7%), MT (68.3%), and TT (78.5%). The relationship of the firing to direction was fit to a cosine tuning function for each significantly modulated cell. In 86.3% of the cells the firing was correlated significantly with a cosine function of movement direction in TT. A cell's preferred direction varied little for different movement distances. The mean difference in preferred direction for the smallest possible change in distance (0.8 cm) was 12.8 +/- 11.4 degrees (SD) and 17.1 +/- 14.7 degrees for the largest change in distance (4.0 cm). 4. Correlation analysis revealed that the activity of the majority of cells was modulated significantly by distance along at least one direction in each of the three time periods, PT (46.8%), MT (68.8%), and TT (67.7%). Subsequently, a univariate linear regression model was used to quantify a cell's discharge as a function of distance. For the regressions of firing with distance with a statistically significant correlation (r > 0.8), the mean slope was 3.59 +/- 0.17 spikes.s-1.cm-1 for the total time. The existence of a significant distance modulation was not invariably correlated with a cell's preferred movement direction.(ABSTRACT TRUNCATED AT 400 WORDS)

Visuomotor Processing as Reflected in the Directional Discharge of Premotor and Primary Motor Cortex Neurons

1999 ◽  
Vol 81 (2) ◽  
pp. 875-894 ◽  
Author(s):  
M.T.V. Johnson ◽  
J. D. Coltz ◽  
M. C. Hagen ◽  
T. J. Ebner
Keyword(s):  
Regression Analysis ◽  
Motor Cortex ◽  
Linear Regression ◽  
Visual Information ◽  
Primary Motor Cortex ◽  
Linear Regression Analysis ◽  
Movement Direction ◽  
Directional Tuning ◽  
Preferred Direction ◽  
Visuomotor Processing

Johnson, M.T.V., J. D. Coltz, M. C. Hagen, and T. J. Ebner. Visuomotor processing as reflected in the directional discharge of premotor and primary motor cortex neurons. J. Neurophysiol. 81: 875–894, 1999. Premotor and primary motor cortical neuronal firing was studied in two monkeys during an instructed delay, pursuit tracking task. The task included a premovement “cue period,” during which the target was presented at the periphery of the workspace and moved to the center of the workspace along one of eight directions at one of four constant speeds. The “track period” consisted of a visually guided, error-constrained arm movement during which the animal tracked the target as it moved from the central start box along a line to the opposite periphery of the workspace. Behaviorally, the animals tracked the required directions and speeds with highly constrained trajectories. The eye movements consisted of saccades to the target at the onset of the cue period, followed by smooth pursuit intermingled with saccades throughout the cue and track periods. Initially, an analysis of variance (ANOVA) was used to test for direction and period effects in the firing. Subsequently, a linear regression analysis was used to fit the average firing from the cue and track periods to a cosine model. Directional tuning as determined by a significant fit to the cosine model was a prominent feature of the discharge during both the cue and track periods. However, the directional tuning of the firing of a single cell was not always constant across the cue and track periods. Approximately one-half of the neurons had differences in their preferred directions (PDs) of >45° between cue and track periods. The PD in the cue or track period was not dependent on the target speed. A second linear regression analysis based on calculation of the preferred direction in 20-ms bins (i.e., the PD trajectory) was used to examine on a finer time scale the temporal evolution of this change in directional tuning. The PD trajectories in the cue period were not straight but instead rotated over the workspace to align with the track period PD. Both clockwise and counterclockwise rotations occurred. The PD trajectories were relatively straight during most of the track period. The rotation and eventual convergence of the PD trajectories in the cue period to the preferred direction of the track period may reflect the transformation of visual information into motor commands. The widely dispersed PD trajectories in the cue period would allow targets to be detected over a wide spatial aperture. The convergence of the PD trajectories occurring at the cue-track transition may serve as a “Go” signal to move that was not explicitly supplied by the paradigm. Furthermore, the rotation and convergence of the PD trajectories may provide a mechanism for nonstandard mapping. Standard mapping refers to a sensorimotor transformation in which the stimulus is the object of the reach. Nonstandard mapping is the mapping of an arbitrary stimulus into an arbitrary movement. The shifts in the PD may allow relevant visual information from any direction to be transformed into an appropriate movement direction, providing a neural substrate for nonstandard stimulus-response mappings.

Functional properties of single neurons in the face primary motor cortex of the primate. III. Relations with different directions of trained tongue protrusion

1992 ◽  
Vol 67 (3) ◽  
pp. 775-785 ◽  
Author(s):  
G. M. Murray ◽  
B. J. Sessle
Keyword(s):  
Motor Cortex ◽  
Firing Rate ◽  
Primary Motor Cortex ◽  
Afferent Input ◽  
Single Neurons ◽  
Tongue Movement ◽  
Midsagittal Plane ◽  
Tongue Protrusion ◽  
Preferred Direction ◽  
The Mean

1. In previous papers we presented evidence pointing to an important role for face motor cortex in the control of tongue movements. Intracortical microstimulation (ICMS) at many sites within face motor cortex evoked different types of tongue movement, and many neurons at these "tongue-MI" sites received intraoral mechanosensitive afferent input, and their activity was related to a tongue-protrusion task performed by a monkey. In view of the synergistic action of the various tongue muscles during tongue movement, we hypothesized that these different tongue-MI sites are recruited to effect the appropriate change in tongue shape and position during a tongue-protrusion movement. A prediction from this hypothesis is that variations in the direction of a tongue-protrusion movement should be associated with variations in the activities within the different tongue-MI efferent zones. Differences in efferent-zone activity should be reflected in differences in the firing rates of neurons that are located at these tongue-MI sites. 2. We trained two monkeys to perform a tongue-protrusion task at each of three directions. The tongue-protrusion task transducer was positioned at 0 degrees (Ts), 30 degrees to the left (Tlt), or 30 degrees to the right (Trt) from the midsagittal plane; the latter two positions were termed asymmetric tongue-protrusion task positions. Single neurons were recorded from tongue-MI during trials of tongue-protrusion task at each of two or three of the above positions. Some of the neurons were also studied during a biting task. In addition, neurons were tested for possible mechanosensitive afferent input. 3. Of the 66 neurons studied, 31 (45%) exhibited directional relations; that is, the change in firing rate between the pretrial period (PTP) and the task period for the tongue-protrusion task was significantly different for each neuron depending on the direction in which the activity of the neuron was studied. 4. The "directional" neurons exhibited a single preferred direction of firing in that the mean firing rate during one direction of tongue-protrusion task was significantly greater than for any other direction. Of the 20 neurons studied at all three directions of tongue-protrusion task, the mean firing rate of each of 18 was highest at one of the asymmetric positions, and 12 of these 18 neurons exhibited a monotonic decrease in absolute firing frequency from one asymmetric task direction to the other. 5. Thirteen of the neurons were also studied while the monkey performed the biting task. Most tongue-MI directional neurons were not related to the biting task.(ABSTRACT TRUNCATED AT 400 WORDS)

Changes in motor cortex activity during reaching movements with similar hand paths but different arm postures

1995 ◽  
Vol 73 (6) ◽  
pp. 2563-2567 ◽  
Author(s):  
S. H. Scott ◽  
J. F. Kalaska
Keyword(s):  
Motor Cortex ◽  
Sagittal Plane ◽  
Single Cells ◽  
Reaching Movements ◽  
Movement Direction ◽  
Tonic Activity ◽  
Population Vector ◽  
Significant Difference ◽  
Direction Of Movement ◽  
Kinematics And Kinetics

1. Neuronal activity was recorded in the motor cortex of a monkey that performed reaching movements with the use of two different arm postures. In the first posture (control), the monkey used its natural arm orientation, approximately in the sagittal plane. In the second posture (abducted), the monkey had to adduct its elbow nearly to shoulder level to grasp the handle. The path of the hand between targets was similar in both arm postures, but the joint kinematics and kinetics were different. 2. In both postures, the activity of single cells was often broadly tuned with movement direction and static arm posture over the targets. In a large proportion of cells, either the level of tonic activity, the directional tuning, or both, varied between the two postures during the movement and target hold periods. 3. For most directions of movement, there was a statistically significant difference in the direction of the population vector for the two arm postures. Furthermore, whereas the population vector tended to point in the direction of movement for the control posture, there was a poorer correspondence between the direction of movement and the population vector for the abducted posture. These observed changes are inconsistent with the notion that the motor cortex encodes purely hand trajectory in space.

Time Course of Determination of Movement Direction in the Reaction Time Task in Humans

2001 ◽  
Vol 86 (3) ◽  
pp. 1195-1201 ◽  
Author(s):  
Martin Sommer ◽  
Joseph Classen ◽  
Leonardo G. Cohen ◽  
Mark Hallett
Keyword(s):  
Reaction Time ◽  
Motor Cortex ◽  
Time Course ◽  
Primary Motor Cortex ◽  
Cortical Excitability ◽  
Motor Evoked Potentials ◽  
Movement Direction ◽  
Movement Onset ◽  
Thumb Movement

The primary motor cortex produces motor commands that include encoding the direction of movement. Excitability of the motor cortex in the reaction time (RT) task can be assessed using transcranial magnetic stimulation (TMS). To elucidate the timing of the increase in cortical excitability and of the determination of movement direction before movement onset, we asked six right-handed, healthy subjects to either abduct or extend their right thumb after a go-signal indicated the appropriate direction. Between the go-signal and movement onset, single TMS pulses were delivered to the contralateral motor cortex. We recorded the direction of the TMS-induced thumb movement and the amplitude of motor-evoked potentials (MEPs) from the abductor pollicis brevis and extensor pollicis brevis muscles. Facilitation of MEPs from the prime mover, as early as 200 ms before the end of the reaction time, preceded facilitation of MEPs from the nonprime mover, and both preceded measurable directional change. Compared with a control condition in which no voluntary movement was required, the direction of the TMS-induced thumb movement started to change in the direction of the intended movement as early as 90 ms before the end of the RT, and maximum changes were seen shortly before the end of reaction time. Movement acceleration also increased with maxima shortly before the end of the RT. We conclude that in concentric movements a change of the movement direction encoded in the primary motor cortex occurs in the 200 ms prior to movement onset, which is as early as increased excitability itself can be detected.

scholarly journals Motor Cortex Neural Correlates of Output Kinematics and Kinetics During Isometric-Force and Arm-Reaching Tasks

2005 ◽  
Vol 94 (4) ◽  
pp. 2353-2378 ◽  
Author(s):  
Lauren E. Sergio ◽  
Catherine Hamel-Pâquet ◽  
John F. Kalaska
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Isometric Force ◽  
Arm Movements ◽  
Population Level ◽  
Emg Activity ◽  
Hand Motion ◽  
Arm Reaching ◽  
Direction Of Movement ◽  
Isometric Forces

We recorded the activity of 132 proximal-arm-related neurons in caudal primary motor cortex (M1) of two monkeys while they generated either isometric forces against a rigid handle or arm movements with a heavy movable handle, in the same eight directions in a horizontal plane. The isometric forces increased in monotonic fashion in the direction of the force target. The forces exerted against the handle in the movement task were more complex, including an initial accelerating force in the direction of movement followed by a transient decelerating force opposite to the direction of movement as the hand approached the target. EMG activity of proximal-arm muscles reflected the difference in task dynamics, showing directional ramplike activity changes in the isometric task and reciprocally tuned “triphasic” patterns in the movement task. The apparent instantaneous directionality of muscle activity, when expressed in hand-centered spatial coordinates, remained relatively stable during the isometric ramps but often showed a large transient shift during deceleration of the arm movements. Single-neuron and population-level activity in M1 showed similar task-dependent changes in temporal pattern and instantaneous directionality. The momentary dissociation of the directionality of neuronal discharge and movement kinematics during deceleration indicated that the activity of many arm-related M1 neurons is not coupled only to the direction and speed of hand motion. These results also demonstrate that population-level signals reflecting the dynamics of motor tasks and of interactions with objects in the environment are available in caudal M1. This task-dynamics signal could greatly enhance the performance capabilities of neuroprosthetic controllers.

scholarly journals Primary Motor Cortex Excitability Is Modulated During the Mental Simulation of Hand Movement

2017 ◽  
Vol 23 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Christian Hyde ◽  
Ian Fuelscher ◽  
Jarrad A.G. Lum ◽  
Jacqueline Williams ◽  
Jason He ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Motor Evoked Potentials ◽  
Hand Movement ◽  
Single Pulse ◽  
Stimulus Presentation ◽  
Mental Simulation ◽  
Right Hand ◽  
Hand Laterality ◽  
Motor Cortex Excitability

AbstractObjectives:It is unclear whether the primary motor cortex (PMC) is involved in the mental simulation of movement [i.e., motor imagery (MI)]. The present study aimed to clarify PMC involvement using a highly novel adaptation of the hand laterality task (HLT).Methods:Participants were administered single-pulse transcranial magnetic stimulation (TMS) to the hand area of the left PMC (hPMC) at either 50 ms, 400 ms, or 650 ms post stimulus presentation. Motor-evoked potentials (MEPs) were recorded from the right first dorsal interosseous via electromyography. To avoid the confound of gross motor response, participant response (indicating left or right hand) was recorded via eye tracking. Participants were 22 healthy adults (18 to 36 years), 16 whose behavioral profile on the HLT was consistent with the use of a MI strategy (MI users).Results:hPMC excitability increased significantly during HLT performance for MI users, evidenced by significantly larger right hand MEPs following single-pulse TMS 50 ms, 400 ms, and 650 ms post stimulus presentation relative to baseline. Subsequent analysis showed that hPMC excitability was greater for more complex simulated hand movements, where hand MEPs at 50 ms were larger for biomechanically awkward movements (i.e., hands requiring lateral rotation) compared to simpler movements (i.e., hands requiring medial rotation).Conclusions:These findings provide support for the modulation of PMC excitability during the HLT attributable to MI, and may indicate a role for the PMC during MI. (JINS, 2017,23, 185–193)

scholarly journals Assessment of Brain Cortical Activation in Passive Movement During Wrist Task Using Functional Near Infrared Spectroscopy (fNIRS)

2019 ◽  
Author(s):  
Maziar Jalalvandi ◽  
Hamid Sharini ◽  
Yousof Naderi ◽  
Nader RiahiAlam
Keyword(s):  
Infrared Spectroscopy ◽  
Motor Cortex ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Primary Motor Cortex ◽  
Passive Movement ◽  
Cortical Activation ◽  
Movement Direction ◽  
Functional Near Infrared Spectroscopy ◽  
Activation Patterns

Purpose: Nowadays, the number of people diagnosed with movement disorders is increasing. Therefore, the evaluation of brain activity during motor task performance has attracted the attention of researchers in recent years. Functional Near-Infrared Spectroscopy (fNIRS) is a useful method that measures hemodynamic changes in the brain cortex based on optical principles. The purpose of this study was to evaluate the brain’s cortical activation in passive movement of the wrist. Materials and Methods: In current study, the activation of the brain's motor cortex during passive movement of the right wrist was investigated. To perform this study, ten healthy young right-handed volunteers were chosen. The required data were collected using a commercial 48-channel continuous wave fNIRS machine, using two different wavelengths of 765 and 855 nm at 10 Hz sampling rate. Results: Analysis of collected data showed that the brain's motor cortex during passive motion was significantly activated (p≤0.05) compared to rest. Motor cortex activation patterns depending on passive movement direction were separated. In different directions of wrist movement, the maximum activation was recorded at the primary motor cortex (M1). Conclusion: The present study has investigated the ability of fNIRS to evaluate cortical activation during passive movement of the wrist. Analysis of recording signals showed that different directions of movement have specific activation patterns in the motor cortex.

scholarly journals Using Nonlinear Dynamics of EEG Signals to Decode Hand Movement Directions Under Bimanual Movement

2021 ◽  
Author(s):  
Jiarong Wang ◽  
Luzheng Bi ◽  
Weijie Fei
Keyword(s):  
Nonlinear Dynamics ◽  
Hand Movement ◽  
Movement Direction ◽  
Bimanual Movement ◽  
Eeg Signals ◽  
Linear Discriminant ◽  
Computer Interfaces ◽  
Opposite Hand ◽  
Movement Parameters ◽  
Human Augmentation

Abstract Background: Decoding hand movement parameters from electroencephalograms (EEG) signals can provide intuitive control for brain-computer interfaces (BCIs). However, most existing studies of EEG-based hand movement decoding are focused on single hand movement. Since the both-hand movement is common in human augmentation systems, to address the decoding of hand movement under the opposite hand movement, we investigate the neural signatures and decoding of the primary hand movement direction from EEG signals under the opposite hand movement. Methods: The decoding model was developed by using an echo state network (ESN) to extract nonlinear dynamics parameters of movement-related cortical potentials (MRCPs) as decoding features and linear discriminant analysis as a classifier. Results: Significant differences in MRCPs between movement conditions with and without an opposite hand movement were found. Furthermore, using the ESN-based models, the decoding accuracies reached 86.03± 7.32% and 88.45± 6.16% under the conditions without and with the opposite hand movement, 20 respectively. Conclusions: These findings showed that the proposed method performed well in decoding the primary hand movement directions under the conditions with and without the opposite hand movement. This study may open a new avenue to decode hand movement parameters from EEG signals and lay a foundation for the future development of BCI-based human augmentation systems.

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