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Decoding Trajectories from Posterior Parietal Cortex Ensembles

Mulliken, Grant H. and Musallam, Sam and Andersen, Richard A. (2008) Decoding Trajectories from Posterior Parietal Cortex Ensembles. Journal of Neuroscience, 28 (48). pp. 12913-12926. ISSN 0270-6474. PMCID PMC2728059. doi:10.1523/JNEUROSCI.1463-08.2008.

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High-level cognitive signals in the posterior parietal cortex (PPC) have previously been used to decode the intended endpoint of a reach, providing the first evidence that PPC can be used for direct control of a neural prosthesis (Musallam et al., 2004). Here we expand on this work by showing that PPC neural activity can be harnessed to estimate not only the endpoint but also to continuously control the trajectory of an end effector. Specifically, we trained two monkeys to use a joystick to guide a cursor on a computer screen to peripheral target locations while maintaining central ocular fixation. We found that we could accurately reconstruct the trajectory of the cursor using a relatively small ensemble of simultaneously recorded PPC neurons. Using a goal-based Kalman filter that incorporates target information into the state-space, we showed that the decoded estimate of cursor position could be significantly improved. Finally, we tested whether we could decode trajectories during closed-loop brain control sessions, in which the real-time position of the cursor was determined solely by a monkey's neural activity in PPC. The monkey learned to perform brain control trajectories at 80% success rate (for 8 targets) after just 4–5 sessions. This improvement in behavioral performance was accompanied by a corresponding enhancement in neural tuning properties (i.e., increased tuning depth and coverage of encoding parameter space) as well as an increase in off-line decoding performance of the PPC ensemble.

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URLURL TypeDescription CentralArticle
Andersen, Richard A.0000-0002-7947-0472
Additional Information:© 2008 Society for Neuroscience. Received April 4, 2008; revised Sept. 13, 2008; accepted Oct. 21, 2008. This work was supported by the National Eye Institute, the James G. Boswell Foundation, the Defense Advanced Research Projects Agency, and a National Institutes of Health training grant fellowship to G.H.M. We thank J. Burdick, E. Hwang, and M. Hauschild for comments on this manuscript, K. Pejsa and N. Sammons for animal care, and V. Shcherbatyuk and T. Yao for technical and administrative assistance.
Funding AgencyGrant Number
National Eye InstituteUNSPECIFIED
James G. Boswell FoundationUNSPECIFIED
Defense Advanced Research Projects Agency (DARPA)UNSPECIFIED
Subject Keywords:brain–machine interface; trajectory decoding; neural prosthetics; sensorimotor control; posterior parietal cortex; neurophysiology
Issue or Number:48
PubMed Central ID:PMC2728059
Record Number:CaltechAUTHORS:MULjns08
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:12463
Deposited By: Archive Administrator
Deposited On:02 Dec 2008 22:55
Last Modified:08 Nov 2021 22:28

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