Philip Holmes
Monday 15th September 2014
Time: 4pm
Basement Seminar Room
Alexandra House, 17 Queen Square, London, WC1N 3AR
A multi-area stochastic accumulator model for a visual search and
decision task
Using behavioral and electrophysiological data from two monkeys
performing a covert visual search and decision task, we develop a
leaky accumulator model for the dynamics of neural populations. The
model represents inferior temporal cortex (ITC), anterior
intraparietal area (AIP), motor cortex and six receptive fields in the
lateral interparietal area (LIP). Parameter values fitted to the data
allow us to propose mechanisms that account for differences between
the animals in terms of connection strengths among ITC, AIP and LIP,
suggesting that they use different strategies to accomplish the task.
More generally, our approach may be of interest in modeling cognitive
tasks that involve multiple brain areas.
If time permits, I will describe how leaky accumulators can be derived
from biophysically based spiking neuron models.
The talk will draw on joint work with Sam Feng, Mike Schwemmer and
Jonathan Cohen, using data kindly provided by Jackie Gottlieb
(Columbia University).
Philip Holmes,
Program in Applied and Computational Mathematics,
Department of Mechanical and Aerospace Engineering,
and Princeton Neuroscience Institute,
Princeton University