Dwight A. Burkhardt PhD is a well known retinal physiologist whose work has extended from the cellular to the behavioral. I first met Dr. Burkhardt 20 years ago while attending his Visual Neuroscience course at the University of Minnesota. My first attempt at computational modeling was as an independent research project with him, which simulated the outer-retina at a cellular level. I subsequently worked in his laboratory (time-sharing with the RF Miller lab) performing electrophysiological experiments in the amphibian retina. Later I developed software for data acquisition and stimulus control, including a unique LCD based visual stimulator. Most recently an algorithm was developed in MatLab that simulates the Tiger Salamander bipolar cell contrast field and was used in analysing natural images. The results were published in

Visual Neuroscience 2006 Jan-Feb;23(1):35-47
Natural images and contrast encoding in bipolar cells in the retina
of the land- and aquatic-phase tiger salamander.


Comparison of the distribution of dynamic ranges for contrast responses across the bipolar cell population and the natural image contrast distribution. The horizontal line shows the dynamic range encompassing 1090% of the total response range for each cell. The heavy lines show the average natural image contrast distribution. A: Bd and Bh cells for land-phase animals. B and C, respectively: Bd and Bh cells for aquatic-phase animals. Diamonds show the dynamic range for cones of aquatic-phase animals.