|
I am interested in how the brain processes sensory information, examined using both behavioral and neurophysiological techniques. I have two broad areas of research: hearing in amphibians, and sensory processing in fish.
My students and I are examining the function of the auditory system under conditions of ionic and osmotic stress, using several species of frogs and toads as a model system. Not only do these amphibians have excellent auditory systems, but the performance of their hearing is maintained under conditions of high plasma salt concentration (as normally occurs when a frog ventures away from water for a day or two). We have found normal hearing function in frogs for salt concentrations that are lethal for mammals! Currently we are developing a reduced preparation using just an isolated brain and auditory organs, to allow rapid experimentally-induced changes in ion and osmolyte concentration while simultaneously recording neural function in response to sound. Ultimately we will learn how a sensory system can be robust in a relatively unbuffered chemical environment.
I have become involved in several different aspects of fish sensory processing. How a fish brain can put together information from different sensory modalities to make an accurate picture of its world is a very exciting project. We are making detailed measurements of the behavioral responses of weakly electric fish presented with objects that move near them. Electric fish are able to sense the presence of an object that has an electrical conductivity different than the water around them. They can also use their mechanosensory lateral line (found in all fish and aquatic amphibians) to detect the water disturbance caused by the moving object. Each sensory system has particular strengths and the fish extract specific information from the mechanical signature and from the electrical signature of the object.
In the past different student projects have examined the habituation of sensory stimuli in weakly electric fish, the neural update rates for different sensory modalities, and the coding of capacitive object information by the nervous system.
| 
