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Spatiotemporal tuning of motor cortical neurons for hand position and velocity.
J Neurophysiol. 2004 Jan; 91(1):515-32.JN

Abstract

A pursuit-tracking task (PTT) and multielectrode recordings were used to investigate the spatiotemporal encoding of hand position and velocity in primate primary motor cortex (MI). Continuous tracking of a randomly moving visual stimulus provided a broad sample of velocity and position space, reduced statistical dependencies between kinematic variables, and minimized the nonstationarities that are found in typical "step-tracking" tasks. These statistical features permitted the application of signal-processing and information-theoretic tools for the analysis of neural encoding. The multielectrode method allowed for the comparison of tuning functions among simultaneously recorded cells. During tracking, MI neurons showed heterogeneity of position and velocity coding, with markedly different temporal dynamics for each. Velocity-tuned neurons were approximately sinusoidally tuned for direction, with linear speed scaling; other cells showed sinusoidal tuning for position, with linear scaling by distance. Velocity encoding led behavior by about 100 ms for most cells, whereas position tuning was more broadly distributed, with leads and lags suggestive of both feedforward and feedback coding. Individual cells encoded velocity and position weakly, with comparable amounts of information about each. Linear regression methods confirmed that random, 2-D hand trajectories can be reconstructed from the firing of small ensembles of randomly selected neurons (3-19 cells) within the MI arm area. These findings demonstrate that MI carries information about evolving hand trajectory during visually guided pursuit tracking, including information about arm position both during and after its specification. However, the reconstruction methods used here capture only the low-frequency components of movement during the PTT. Hand motion signals appear to be represented as a distributed code in which diverse information about position and velocity is available within small regions of MI.

Authors+Show Affiliations

Center for Neural Science, New York University, New York, New York 10003, USA.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

13679402

Citation

Paninski, Liam, et al. "Spatiotemporal Tuning of Motor Cortical Neurons for Hand Position and Velocity." Journal of Neurophysiology, vol. 91, no. 1, 2004, pp. 515-32.
Paninski L, Fellows MR, Hatsopoulos NG, et al. Spatiotemporal tuning of motor cortical neurons for hand position and velocity. J Neurophysiol. 2004;91(1):515-32.
Paninski, L., Fellows, M. R., Hatsopoulos, N. G., & Donoghue, J. P. (2004). Spatiotemporal tuning of motor cortical neurons for hand position and velocity. Journal of Neurophysiology, 91(1), 515-32.
Paninski L, et al. Spatiotemporal Tuning of Motor Cortical Neurons for Hand Position and Velocity. J Neurophysiol. 2004;91(1):515-32. PubMed PMID: 13679402.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Spatiotemporal tuning of motor cortical neurons for hand position and velocity. AU - Paninski,Liam, AU - Fellows,Matthew R, AU - Hatsopoulos,Nicholas G, AU - Donoghue,John P, Y1 - 2003/09/17/ PY - 2003/9/19/pubmed PY - 2004/3/3/medline PY - 2003/9/19/entrez SP - 515 EP - 32 JF - Journal of neurophysiology JO - J Neurophysiol VL - 91 IS - 1 N2 - A pursuit-tracking task (PTT) and multielectrode recordings were used to investigate the spatiotemporal encoding of hand position and velocity in primate primary motor cortex (MI). Continuous tracking of a randomly moving visual stimulus provided a broad sample of velocity and position space, reduced statistical dependencies between kinematic variables, and minimized the nonstationarities that are found in typical "step-tracking" tasks. These statistical features permitted the application of signal-processing and information-theoretic tools for the analysis of neural encoding. The multielectrode method allowed for the comparison of tuning functions among simultaneously recorded cells. During tracking, MI neurons showed heterogeneity of position and velocity coding, with markedly different temporal dynamics for each. Velocity-tuned neurons were approximately sinusoidally tuned for direction, with linear speed scaling; other cells showed sinusoidal tuning for position, with linear scaling by distance. Velocity encoding led behavior by about 100 ms for most cells, whereas position tuning was more broadly distributed, with leads and lags suggestive of both feedforward and feedback coding. Individual cells encoded velocity and position weakly, with comparable amounts of information about each. Linear regression methods confirmed that random, 2-D hand trajectories can be reconstructed from the firing of small ensembles of randomly selected neurons (3-19 cells) within the MI arm area. These findings demonstrate that MI carries information about evolving hand trajectory during visually guided pursuit tracking, including information about arm position both during and after its specification. However, the reconstruction methods used here capture only the low-frequency components of movement during the PTT. Hand motion signals appear to be represented as a distributed code in which diverse information about position and velocity is available within small regions of MI. SN - 0022-3077 UR - https://www.unboundmedicine.com/medline/citation/13679402/Spatiotemporal_tuning_of_motor_cortical_neurons_for_hand_position_and_velocity_ L2 - https://journals.physiology.org/doi/10.1152/jn.00587.2002?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -