SNSF | P3 Research Database

hand grasping; neural prosthetics; premotor cortex; parietal cortex; local field potential

English title	Hand grasping signals in the premotor and parietal cortex
Applicant	Scherberger Hansjörg
Number	108323
Funding scheme	Project funding
Research institution	Institut für Neuroinformatik Universität Zürich Irchel und ETH Zürich
Institution of higher education	University of Zurich - ZH
Main discipline	Neurophysiology and Brain Research
Start/End	01.04.2005 - 31.03.2008
Approved amount	260'000.00

Lead

Lay summary
Hand grasping signals in the premotor and parietal cortex Hansjörg Scherberger Institute of Neuroinformatics, University and ETH Zurich, 8057 Zurich, Switzerland The use of the human hand plays a central role in our motor behavior and what defines us of being human. Many brain areas are involved in the generation of hand movements, but two regions in the premotor and parietal cortex play a particular important role for the initial, or high-level, planning of hand movements. The generation of these first hand movement intentions involves the transformation of visual information into a motor plan that can be further processed and executed. In paralyzed patients, e.g., patients with severe spinal cord injury or stroke, the execution of such movements is disrupted, but the planning capacity for hand movements in the brain is still preserved. While neural commands can no longer reach the hand muscles, it may be possible to artificially read out and interpret these brain signals and deliver them to either the natural or a prosthetic hand - if one would understand how hand planning signals are generated and represented in the brain. This project investigates how intentions to move the hand are generated and represented in the brain of macaque monkeys. Animals are trained to perform a delayed hand grasping task, in which an object can be grasped with two different grasping behaviors (precision grip or power grip) and in 5 different hand orientations. Animals are rewarded for each successful execution of the task with small amount of juice. Once the animal has learned the task, neural activity is recorded from two brain areas, the anterior intraparietal area (AIP) and the area F5, which both generate early hand grasping instructions. By correlating the neural responses with each other and with the animal’s behavior, it is determined how high-order grasping plans are encoded in AIP and F5 and how these areas interact. For these experiments, the use of macaque monkeys (rhesus monkeys) is essential for several reasons. First, only primates share with humans the dominant role of the visual system, the hand dexterity, and the way objects are grasped. Other species don’t have this hand dexterity. Second, since the ultimate goal of understanding the hand movement system is to develop a neural prosthesis for human patients, studying the neural control of hand grasping in non-human primates is a necessary and appropriate fist step prior to human applications. We expect that results from this study will bring us several steps closer to understanding how hand movements are generated in the primate brain.