Spiking activity from neurophysiological experiments often exhibits dynamics beyond that driven by external stimulation, presumably reflecting the extensive recurrence of neural circuitry. Characterizing these dynamics may reveal important features of neural computation, particularly during internally-driven """"""""cognitive"""""""" operations. For example, neurons in premotor cortex (PMd) are active during a """"""""planning"""""""" period separating movement-target specification and a movement-initiation cue. Recent evidence suggests that PMd neural activity settles to a movement-specific state during this period. Can trial-to-trial variation in behavior be predicted from the dynamics of settling? Current methods to characterize recurrent neural dynamics on a trial-by-trial basis, and thus answer this and related questions, are limited. Standard methods average activity from different trials or different cells, and so cannot express variable dynamics. The proposed research will test the hypothesis that the dynamics underlying PMd plan activity can be described by a low-dimensional hidden non-linear dynamical systems (HNLDS) model, with underlying recurrent structure and stochastic point-process output. Such a model is capable of expressing rich dynamics, but the task of learning the model parameters from spike data is challenging. The proposed research will develop and validate algorithms for parameter estimation, and then characterize the dynamics in PMd data recorded from an electrode array while monkeys perform delayed-reach tasks. Single trial estimates of underlying dynamics can then be used to predict variation in details of reaching motor behavior. The proposed research program will directly inform cortically-controlled neural prosthesis research in our laboratory and elsewhere. Such motor and communication prostheses could dramatically improve the quality of life for patients with upper spinal cord injuries, amputations, ALS and other neuro-degenerative diseases. The proposed research program will increase our understanding of how PMd rapidly prepares movements, and thereby help increase the speed and accuracy of prosthetic systems.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS054283-05
Application #
7674692
Study Section
Special Emphasis Panel (ZRG1-IFCN-B (50))
Program Officer
Liu, Yuan
Project Start
2005-09-01
Project End
2011-08-31
Budget Start
2009-09-01
Budget End
2011-08-31
Support Year
5
Fiscal Year
2009
Total Cost
$350,432
Indirect Cost
Name
Stanford University
Department
Engineering (All Types)
Type
Schools of Engineering
DUNS #
009214214
City
Stanford
State
CA
Country
United States
Zip Code
94305
Kao, Jonathan C; Nuyujukian, Paul; Ryu, Stephen I et al. (2017) A High-Performance Neural Prosthesis Incorporating Discrete State Selection With Hidden Markov Models. IEEE Trans Biomed Eng 64:935-945
Kaufman, Matthew T; Churchland, Mark M; Ryu, Stephen I et al. (2015) Vacillation, indecision and hesitation in moment-by-moment decoding of monkey motor cortex. Elife 4:e04677
Nuyujukian, Paul; Fan, Joline M; Kao, Jonathan C et al. (2015) A high-performance keyboard neural prosthesis enabled by task optimization. IEEE Trans Biomed Eng 62:21-29
Christie, Breanne P; Tat, Derek M; Irwin, Zachary T et al. (2015) Comparison of spike sorting and thresholding of voltage waveforms for intracortical brain-machine interface performance. J Neural Eng 12:016009
Nuyujukian, Paul; Kao, Jonathan C; Fan, Joline M et al. (2014) Performance sustaining intracortical neural prostheses. J Neural Eng 11:066003
Fan, Joline M; Nuyujukian, Paul; Kao, Jonathan C et al. (2014) Intention estimation in brain-machine interfaces. J Neural Eng 11:016004
Bishop, William; Chestek, Cynthia C; Gilja, Vikash et al. (2014) Self-recalibrating classifiers for intracortical brain-computer interfaces. J Neural Eng 11:026001
Kaufman, Matthew T; Churchland, Mark M; Ryu, Stephen I et al. (2014) Cortical activity in the null space: permitting preparation without movement. Nat Neurosci 17:440-8
Kaufman, Matthew T; Churchland, Mark M; Shenoy, Krishna V (2013) The roles of monkey M1 neuron classes in movement preparation and execution. J Neurophysiol 110:817-25
Kao, Jonathan C; Nuyujukian, Paul; Stavisky, Sergey et al. (2013) Investigating the role of firing-rate normalization and dimensionality reduction in brain-machine interface robustness. Conf Proc IEEE Eng Med Biol Soc 2013:293-8

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