Daniel W. Moran, Ph.D.
300F Whitaker Hall
neurobiology, neuroprosthetics, motor control
Neurophysiology of volitional arm movements and its application to neuroprosthetics
My primary research interest is in the area of voluntary motor control. My lab investigates how various neural substrates control voluntary movement. Specifically, I am interested in cortical representation of arm movements. Our recent findings show that individual cells in the primary motor cortex encode both the direction and speed of an impending movement. Combining the activity of a number (~100) of these motor cortical cells, a high-fidelity prediction of hand velocity is observed approximately a tenth of a second before it is performed by the limb. This information has been utilized by several research groups for both open-loop, real-time kinematic control of robotic arms as well as closed-loop control of a virtual reality environment.
Motor learning and neural plasticity is another research area in which I am very interested. All the motor cortical studies to date have used over-trained subjects during their recordings in order to average data over many recording sessions. However, with recent advances in multi, single-unit chronic recording methods, a naive subject can be recorded over a period of months to investigate what role various areas of cerebral cortex play in motor learning. How motor cortical activity changes over multiple motor learning sessions is invaluable data for designing motor cortical controlled neuroprostheses.
Future research projects will involve controlling complex 3D musculoskeletal models with cortical signals. This research will initially utilize real-time cortical recordings in non-human primates in a virtual reality environment. However, instead of controlling arm kinematics directly, the cortical signal would be applied through optimization routines which will determine individual muscle activation levels. These levels would then be fed through the musculoskeletal model of the arm with the resulting kinematics displayed by the virtual arm. When successful, the subjects arm could be deenervated and implanted with stimulators for experimental testing of FNS restoration of voluntary arm movement by a cortical implant.
Leuthardt EC, Schalk G, Wolpaw JR, Ojemann JG and Moran DW. A brain computer interface using electrocorticographic signals in humans. Journal of Neural Engineering 2004 Vol 1, No 2, pp. 63-71.
Schwartz AB, Cui XT, Weber DJ and Moran DW. Brain-controlled interfaces: movement restoration with neural prosthetics. Neuron. 2006 Vol 52, pp 205-220.
Chan SS and Moran DW. Computational model of a primate arm: from hand position to joint angles, joint torques and muscle forces. Journal of Neural Engineering 2006 Vol 3, pp 327-337.
Heldman DA, Wang W, Chan SS and Moran DW. Local field potential spectral tuning in motor cortex during reaching. IEEE Transactions on Neural Systems and Rehabilitation Eng. 2006 Vol 14, No 2, pp 180-183.
Wang W, Chan SS, Heldman DA and Moran DW. Motor cortical representation of position and velocity during reaching. Journal of Neurophysiology 2007 Vol 97, pp. 4258-4270.
Last Updated: 8/10/2012 12:09:58 PM