Comparative analysis of electrosensory processing

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Animals rely on their sense organs to collect information on their environment. The brain then needs to extract information that is relevant for behavioural decisions. This involves, for example, the segregation of objects from their background as well as the determination of important object features such as size, distance, or speed of movement. The successful performance in these tasks enables animals to forage, to escape predators, and to communicate. If we are to understand the mechanisms by which the brain solves these problems, we first need to understand what the relevant sensory stimuli are that a given organism needs to extract and then we can ask the appropriate questions about how the nervous system accomplishes this task. Weakly electric fish have become a prime model system in which to study how the brain processes sensory information, because the sensory stimuli (electric fields) are easy to measure and reproduce in an experimental setting and because the electrosensory system is accessible for neurophysiological experimentation. Electric fish probe their environment with self-generated electric fields and sense perturbations of the electric field with electroreceptors in their skin. My goal is to compare how different types of electric fish that use different probing strategies (discrete pulses versus continuous sampling) process the categorically different incoming sensory information. The neural circuits used for sampling information on the environment are virtually identical in the two groups, yet they have to contend with very different stimuli. The results of this investigation will shed light on how sensory systems evolve to process novel types of information caused by a change in interaction with the environment.