• M.S. Biomedical Engineering, May 2005
  Area of Emphasis: Neuromusculoskeletal Movement
  University of Wisconsin-Madison, Madison, WI

• B.S. Biomedical Engineering, December 2002
  University of Wisconsin-Madison, Madison, WI

Major Advisor(s):

• Timothy J. Ebner, M.D., Ph.D.

Research Description:

My projected thesis work in Dr. Ebner’s lab will build upon methods developed for recording the electrical signals from single Purkinje cells in the pars intermedia and hemisphere of the cerebellar cortex of monkeys trained in a manual tracking task.  A predominant contemporary hypothesis is that the cerebellum functions as an inverse dynamics model.  Previous work by the Ebner laboratory has shown that Purkinje cells do not carry signals regarding limb dynamics; this observation is inconsistent with the cerebellum being the site of an inverse dynamics model.  However, these results were based upon experiments where monkeys tracked a visually moving target.  It could be argued that the lack of force modulation was due to the kinematic nature of the task.  This raises the question of whether Purkinje cells would respond to force modulation and signal limb dynamics if the task involved explicitly controlling force and used force feedback.  My future work will look at the role of the cerebellum in force modulation during a haptic tracking task.  This will utilize aspects of a computer program that I helped develop during my lab rotation to simulate a force-controlled environment with a robotic arm.  The robotic arm guides a trained primate along different movement patterns (such as a circle) based solely upon viscous and elastic force output without confounding visual stimuli.  The animal must track this force target using haptic feedback.  The final simulated environment could probably best be compared to a moving corner; a person who was blindfolded but had one hand each on two adjoining walls that moved conjointly in different patterns could use the moving corner to guide him or herself along the path.  Although this tracking task is much more difficult than the previously used moving visual target, preliminary testing showed promise that the task could be performed with training and practice.  Recordings of cellular firing collected during the task will then be analyzed for relationships to anatomical position, direction, velocity, and force.  Correlations or non-correlations with changing force conditions will help determine the role of cerebellar Purkinje cells, if any, in controlling the limb force in a force control and force feedback task.

Lab Rotations:

• Apostolos Georgopoulos
• Tim Ebner
• Bin He

Courses Taken Beyond the Core Courses:

• Medical school courses

Graduate Level Minor:

• Medicine