Toward the study of brain mechanisms underlying free behavior in laboratory settings, by Eli Nelken
The links between brain activity and behavior are often studied using very constrained tasks involving simple binary choices. We wanted to operationalize the notion of the use of sensory (specifically auditory) information to drive behavior, and for that purpose we developed a setup (the RIFF – rat interactive fantasy facility) that allows us to implement general Markov decision processes (MDPs) with a large number of action choices (up to 12 different ports for accessing food and water) based on auditory cues. The use of MDPs makes it possible to apply reinforcement learning theory in order to calculate optimal policies. Rats can freely move in the RIFF, and brain activity is recorded using telemetry or neural loggers on the animal. I will describe the RIFF and the theory underlying it, and present preliminary results regarding (1) the behavior of rats in the RIFF and its correspondence with optimal policies as well as optimal policies under information constraints; (2) neural activity recorded in primary auditory cortex as well as in the auditory field within the insular cortex, and its dependence on behavioral state.
Following undergraduate studies in physics and mathematics, I switched my interests to neuroscience. I finished my Ph.D. in 1991, did a postdoc and Johns Hopkins University (Baltimore, MD, USA) 1991-4, and returned to Hebrew University as faculty in 1994. I’m a full professor since 2008, and currently I’m a director of the Edmond and Lily Safra Center for Brain Sciences (jointly with Prof. Adi Mizrahi). I’m interested in the coding of complex sounds by neural activity, and studied in depth the coding of surprising sounds in the ascending auditory system. More recently I started studying the links between sensory stimuli and the consequent behavior.