A novel experimental system for investigation of cortical activities related to lower limb movements

We report the development of a novel experimental system for investigation of potential correlation between cortical neuronal signals and lower limb movement with targeted application towards cortical controlled neuroprosthesis. The system consists of a specially designed chair and a virtual reality based task environment. We designed a training paradigm for non-human primates to perform whole leg full extension and retraction task that simulates standing and sitting. With the special chair, the 'stand up' and 'sit down' can be performed with the head fixed, which is required for steady and especially acute cortical recordings. In this experimental environment we can simultaneously record leg kinematics during simulated stand up and stepping, ground reaction forces, leg muscle activities and neuronal activities in different cortical areas through either microdriveable electrodes or chronically implanted arrays. With this system and other state-of-the-art techniques, and combined with computational tools that we are developing, we aim to identify neural activity patterns that correlate with muscle activity and/or kinematics associated with leg movement during standing and stepping activities under naive and well trained conditions.