David Barrett
Wednesday 25th February 2015
Time: 4pm
B10 Basement Floor Seminar Room
Alexandra House, 17 Queen Square, London, WC1N 3AR
Optimal compensation for neuron death
The brain has an impressive ability to withstand neural damage.
Diseases that kill neurons can go unnoticed for years, and acute
conditions such as silent stroke have little impact on neural
function. How does the brain compensate for such damage, and what are
the limits of this compensation? In this talk, I will propose that
neural circuits optimally compensate for neuron death, thereby
preserving their function as much as possible. I will show that this
compensation can explain changes in tuning curves induced by neuron
silencing across a variety of systems, including the primary visual
cortex. I will also demonstrate that optimal compensation can be
implemented through the dynamics of networks with a tight balance of
excitation and inhibition, without requiring synaptic plasticity. The
limits of this compensatory mechanism are reached when excitation and
inhibition become unbalanced, thereby demarcating a recovery boundary,
where signal representation fails and where diseases may become
symptomatic.
Biography: David Barrett is a research associate at the Computational
and Biological Learning Lab in Cambridge University, and a College
Research Associate at St John's College, Cambridge. His research
focuses on understanding the neural network mechanisms underlying
neural computation. David received an undergraduate degree in
Theoretical Physics from Trinity College Dublin in 2006, and an M.Sc
in Sparse Coding in 2007. He completed a Ph.D at the Gatsby Unit in
2012 with Prof. Peter Latham. He then held a joint-research position
at the École Normale Supérieure, Paris and the Champalimaud Centre for
the Unknown, Lisbon, before moving to Cambridge.