ICLM Journal Club
This Week
Alexandra Stolyarova
Title: A role for basolateral amygdala in updating expected outcome value in uncertain environments
Many everyday decisions from foraging for food to choosing between investment options rely on representations of expected outcome values that are based on previous experience. In naturalistic settings, outcomes of choices are not singular events of constant value but are instead embedded in dynamic reward distributions that fluctuate from one experience to the next. Basolateral amygdala (BLA) and orbitofrontal cortex (OFC) participate in outcome valuation in such volatile environments but their specific roles in this process are frequently difficult to dissociate. To systematically study the neural mechanisms of value updating in uncertain reward conditions, we developed a novel choice task in rodents in which outcome values are determined by normally-distributed delays to reward receipt. At baseline, rats are required to respond to one of two options on a touchscreen, each identical in mean reward rate (1 sucrose pellet/ 10s) but different in the variance of outcome distributions. Following the establishment of stable performance, rats experience reward upshifts (1/ 5s with variance kept constant) and downshifts (1/ 20s) on each option independently and in counterbalanced order, always followed by a return to baseline conditions. This approximates outcome variability encountered by animals in more naturalistic settings. I will summarize results from molecular, computational modeling, and lesion experiments in our lab utilizing this behavioral paradigm, demonstrating a specific role for BLA in guiding choice behavior under conditions of uncertainty and updating value expectations in response to changes in reward conditions. Preliminary evidence suggests OFC may anchor choice to the mean rate of reward, and that BLA instead dynamically adjusts the learning rate, or the degree to which value estimates are updated in response to new reward information, to guide flexible choice behavior in volatile environments.
About Us
Introduction
The Integrative Center for Learning and Memory (ICLM) is a multidisciplinary center of UCLA labs devoted to understanding the neural basis of learning and memory and its disorders. This will require a unified approach across different levels of analysis, including;
1. Elucidating the molecular cellular and systems mechanisms that allow neurons and synapses to undergo the long-term changes that ultimately correspond to 'neural memories'.
2. Understanding how functional dynamics and computations emerge from complex circuits of neurons, and how plasticity governs these processes.
3. Describing the neural systems in which different forms of learning and memory take place, and how these systems interact to ultimately generate behavior and cognition.
History of ICLM
The Integrative Center for Learning and Memory formally LMP started in its current form in 1998, and has served as a platform for many interactions and collaborations within UCLA. A key event organized by the group is the weekly ICLM Journal Club. For more than 10 years, graduate students, postdocs, principal investigators, and invited speakers have presented on topics ranging from the molecular mechanisms of synaptic plasticity, through computational models of learning, to behavior and cognition. Dean Buonomano oversees the ICLM journal club with help of student/post doctoral organizers. For other events organized by ICLM go to http://www.iclm.ucla.edu/Events.html.
Current Organizers:
Walt Babiec (O'Dell Lab) & Helen Motanis (Buonomano Lab)
Current Faculty Advisor:
Past Organizers:
i) Anna Matynia(Aug 2004 - Jun 2008) (Silva Lab)
ii) Robert Brown (Aug 2008 - Jun 2009) (Balleine Lab)
iii) Balaji Jayaprakash (Aug 2008 - Nov 2011) (Silva Lab)
iv) Justin Shobe & Thomas Rogerson (Dec 2011 - June 2013) (Silva Lab)
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