The representation of arm movements in postcentral and parietal cortex

Kalaska, John

doi:10.1139/y88-075

Cited by 78 publications

(28 citation statements)

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“…Our data indicate that area 2/5 delivers directional information to M1 after movement progresses. Previous studies have suggested that this input from area 2/5 neurons subserves error correction of movement trajectory (Bullock et al 1998;Buneo and Andersen 2006;Kalaska 1988;Kalaska et al 1983;Mulliken et al 2008;Sabes 2000). Our data do not directly address this hypothesis.…”

Section: Discussioncontrasting

confidence: 87%

Population interactions between parietal and primary motor cortices during reach

Menzer

Rao

Bondy

et al. 2014

Journal of Neurophysiology

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Menzer DL, Rao NG, Bondy A, Truccolo W, Donoghue JP. Population interactions between parietal and primary motor cortices during reach. J Neurophysiol 112: 2959 -2984, 2014. First published September 10, 2014; doi:10.1152/jn.00851.2012.-Neural interactions between parietal area 2/5 and primary motor cortex (M1) were examined to determine the timing and behavioral correlates of corticocortical interactions. Neural activity in areas 2/5 and M1 was simultaneously recorded with 96-channel microelectrode arrays in three rhesus monkeys performing a center-out reach task. We introduce a new method to reveal parietal-motor interactions at a population level using partial spike-field coherence (PSFC) between ensembles of neurons in one area and a local field potential (LFP) in another. PSFC reflects the extent of phase locking between spike times and LFP, after removing the coherence between LFPs in the two areas. Spectral analysis of M1 LFP revealed three bands: low, medium, and high, differing in power between movement preparation and performance. We focus on PSFC in the 1-10 Hz band, in which coherence was strongest. PSFC was also present in the 10 -40 Hz band during movement preparation in many channels but generally nonsignificant in the 60 -200 Hz band. Ensemble PSFC revealed stronger interactions than single cell-LFP pairings. PSFC of area 2/5 ensembles with M1 LFP typically rose around movement onset and peaked ϳ500 ms afterward. PSFC was typically stronger for subsets of area 2/5 neurons and M1 LFPs with similar directional bias than for those with opposite bias, indicating that area 2/5 contributes movement direction information. Together with linear prediction of M1 LFP by area 2/5 spiking, the ensemble-LFP pairing approach reveals interactions missed by single neuron-LFP pairing, demonstrating that corticocortical communication can be more readily observed at the ensemble level.cortico-cortical interactions; population spike-field coherence; reach PLANNING AND PERFORMANCE of goal-directed arm reach requires the coordination of interconnected neuron populations across brain areas. Neurons in the arm area of primary motor cortex (M1) and more anterior parts of the posterior parietal cortex (area 2/5) are bidirectionally connected, and single-neuron studies show that they are engaged during reach planning and performance, with partially overlapping timing (Kalaska 1996). However, the temporal and spatial dynamics of parietalfrontal network communication during reach planning and performance are poorly understood. One difficulty in revealing computations that occur in area 2/5-M1 interactions with sin-

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Section: Discussioncontrasting

confidence: 87%

Population interactions between parietal and primary motor cortices during reach

Menzer

Rao

Bondy

et al. 2014

Journal of Neurophysiology

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“…Such vectorial representations of movement have been supported by electrophysiological studies in primate cortex, which indicate that neuronal activity varies with the direction of intended hand motion (Georgopoulos 1994(Georgopoulos , 1995(Georgopoulos , 1996(Georgopoulos , 2000Kakei et al 1999;Kalaska 1988;Kalaska et al 1983). However, it should be emphasized that this hypothesis remains controversial because other studies have reported correlations of motor and premotor unit activity with other variables including hand position (Kettner et al FIG. 6.…”

Section: Specification Of Movement Direction and Extentmentioning

confidence: 85%

Effects of Altering Initial Position on Movement Direction and Extent

Sainburg¹,

Lateiner

Latash

et al. 2003

Journal of Neurophysiology

103

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. Effects of altering initial position on movement direction and extent. J Neurophysiol 89: 401-415, 2003; 10.1152/jn.00243.2002. The purpose of this study was to examine the relative influence of initial hand location on the direction and extent of planar reaching movements. Subjects performed a horizontal-plane reaching task with the dominant arm supported above a table top by a frictionless air-jet system. A start circle and a target were reflected from a horizontal projection screen onto a horizontally positioned mirror, which blocked the subject's view of the arm. A cursor, representing either actual or virtual finger location, was only displayed between each trial to allow subjects to position the cursor in the start circle. Prior to occasional "probe trials," we changed the start location of the finger relative to the cursor. Subjects reported being unaware of the discrepancy between cursor and finger. Our results indicate that regardless of initial hand location, subjects did not alter the direction of movement. However, movement distance was systematically adjusted in accord with the baseline target position. Thus when the hand start position was perpendicularly displaced relative to the target direction, neither the direction nor the extent of movement varied relative to that of baseline. However, when the hand was displaced along the target direction, either anterior or posterior, movements were made in the same direction as baseline trials but were shortened or lengthened, respectively. This effect was asymmetrical such that movements from anterior displaced positions showed greater distance adjustment than those from posterior displaced positions. Inverse dynamic analysis revealed substantial changes in elbow and shoulder muscle torque strategies for both right/left and anterior/posterior pairs of displacements. In the case of right/left displacements, such changes in muscle torque compensated changes in limb configuration such that movements were made in the same direction and to the same extent as baseline trials. Our results support the hypothesis that movement direction is specified relative to an origin at the current location of the hand. Movement extent, on the other hand, appears to be affected by the workspace learned during baseline movement experience.

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“…Reversible lesions of the superior colliculus caused changes in the direction and amplitude of saccades that were consistent with the use of vector averaging and inconsistent with the use of vector summation to convert collicular activity into a command for saccadic eye movements (Lee et al, 1988). Recordings from the sensory and motor cortex have demonstrated distributed codes for the direction of arm movement that could be read by either vector averaging or vector summation (Georgopoulos et al, 1986;Kalaska, 1988).…”

Section: Why Vector Averaging?mentioning

confidence: 97%

Vector Averaging for Smooth Pursuit Eye Movements Initiated by Two Moving Targets in Monkeys

1997

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The visual input for pursuit eye movements is represented in the cerebral cortex as the distributed activity of neurons that are tuned for both the direction and speed of target motion. To probe how the motor system uses this distributed code to compute a command for smooth eye movements, we have recorded the initiation of pursuit for 150 msec presentations of two spots moving at different speeds and/or in different directions. With equal probability, one of the two spots continued to move at the same speed and in the same direction and became the tracking target, whereas the other disappeared and served as a distractor. We measured eye acceleration in the interval from 110 to 206 msec after the onset of spot motion, within both the open-loop interval for pursuit and the interval during which eye motion was affected by the two spots. Our results demonstrate that weighted vector averaging is used to combine the responses to two moving spots. We found only a minute number of responses that were consistent with either vector summation or winner-take-all computations. In addition, our data show that it is difficult for the monkey to defeat vector averaging without extended training on the use of an explicit cue about which spot will become the target. We argue that our experiment reveals the computations done by the pursuit system in the absence of attentional bias and that vector averaging is normally used to read the distributed code of image motion when there is only one target.

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The representation of arm movements in postcentral and parietal cortex

Cited by 78 publications

References 0 publications

Population interactions between parietal and primary motor cortices during reach

Population interactions between parietal and primary motor cortices during reach

Effects of Altering Initial Position on Movement Direction and Extent

Vector Averaging for Smooth Pursuit Eye Movements Initiated by Two Moving Targets in Monkeys

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