Washington University, School of Medicine Dept of Anatomy & Neurobiology
Wednesday 13 October 2010
Seminar Room B10 (Basement)
Alexandra House, 17 Queen Square, London, WC1N 3AR
Your attention, please: The role of LIP in behavior
I'll extensively review the history of the conflicting potential roles for LIP in behavior, including both single neuron recordings and lesion studies. I will then present new data from a decision task that provides evidence for a very specific role in the eye movement system.
We record activity in LIP while animals decide on a trial-to-trial basis which of two targets are likely to provide a larger pay-off. Similar studies have been published by Glimcher and colleagues, Shadlen and colleagues, and others. These studies show that LIP activity is correlated with an internal estimate of target value. However, in all of these studies, animals responded to the task by making an eye movement.
Thus, we do not know if value-related activity in LIP represents an abstract encoding of target value, or is specific to the saccadic eye movement system. We now present data from interleaved trials in which animals indicate their choice using an eye movement (on some trials) or an arm movement (in other trials). Coding of target value in LIP occurs only on eye movement trials. The audience will be invited to participate in a discussion of the implications of this result for the organization of the brain.