Major Projects

 1.    Effect of deep brain stimulation (DBS) settings on the posture and locomotion control in PD: This study will be very helpful in selecting the optimum stimulation parameter settings of deep brain stimulation in PD.  In addition to traditional measures, advanced techniques from chaos and fractal theory and statistical mechanics are being used to quantify the posture (from center of pressure data) and locomotion control (from gait parameters and center of mass data).  Our initial study exploring the effects of different amplitudes of stimulation on postural control in four PD subjects showed decrease in posture shift velocity and unsteadiness while reaching for targets during altered (reduced) amplitude of stimulation.  This may be attributed to increased bradykinesia and rigidity due to altered stimulation conditions.  This opens the window to explore the possibility of using posture shift velocity as an indicator for the quantitative selection of optimum stimulation parameters of DBS. 

2.     Detection and estimation of direction of information flow: The detection of direction of information of flow between observed EEG traces (measured from different locations of the brain) is being carried out, for better predictability of epileptic seizure and identification of epileptic focus using nonlinear and linear dynamical techniques.  We have developed novel techniques based on state-space approach and methodology for the proper selection of critical parameters involved in the estimation of transfer of entropy.  These can also be effectively used to understand information exchange in the basal ganglia structures in PD. 

3.     Mechanism of learning and adaptation in primates: Understanding the mechanism of learning and adaptation involved in task-reaching in primates, from multi-unit neural recordings using techniques from information theory.  From preliminary study, the presence of increasing and decreasing trends of interactions (plasticity) across days between neurons in different cortical regions or within a same cortical region is observed.  The analysis of shuffled spike-time data indicates towards spatial firing patterns of neurons as a possible mechanism for the plasticity observed.