[CTN] CTN seminar: Prof. Peter Shizgal, Oct 25, 3:30, PAS 2464

[Matthijs van der Meer]

Dear all,

Please join us for next Tuesday's CTN seminar (October 25) by Prof.
Peter Shizgal of Concordia University. Title and abstract follow below.

Time and place are the usual, 3.30pm on Tuesday in PAS 2464. Also as
usual, I invite you to submit an updated single slide to highlight
recent/ongoing/future work; if I get enough, these will be shown after
the talk.

If you would like to meet with Prof. Shizgal, and/or come to dinner,
please let me know.

Hope to see you all there!

- Matt


Title: The neural computation of utility: contributions from the study
of brain stimulation reward

Prof. Peter Shizgal, Concordia University Research Chair

http://csbn.concordia.ca/Faculty/Shizgal/

Abstract: Foraging entails repeated decisions about which prey objects
to select, how much effort to invest in their pursuit, when to persist,
and when to desist. These decisions are based on estimates of returns,
costs, and risks. The phenomenon of intracranial selfstimulation has
been used to implement a laboratory analog of foraging in which costs,
and risks can be controlled precisely, and returns arise from an
observable stream of action potentials in an identifiable population of
neurons. Although the directly activated neurons responsible for
intracranial self-stimulation are largely non-dopaminergic, performance
is altered profoundly by changes in dopaminergic neurotransmission.
Consensus has yet to be reached concerning the stage(s) of processing at
which dopamine neurons intervene and how the influence of these neurons
is partitioned between the investment of effort and the evaluation of
returns, costs, and risks. I have developed a model linking allocation
of behavior to the subjective strength, cost, and likelihood of the
rewarding stimulation. Simulations of model output and analysis of
empirical data demonstrate that the methods used previously to assess
performance for brain stimulation reward produce fundamentally ambiguous
results. Using a new measurement method that eliminates this ambiguity,
we have reassessed the contribution of dopamine to performance for brain
stimulation reward. The model linking behavioral allocation to the
subjective strength, cost, and likelihood of reward will be described
along with the changes in intracranial self-stimulation produced by
cocaine and by the selective dopamine re-uptake inhibitor, GBR-12909.
These results will be discussed in terms of the stage(s) of processing
at which dopamine influences the pursuit of rewards and in terms of the
distinction between the sensitivity and gain of brain reward circuitry.