Title: Cortical Dynamics of Decision Making and Learning
Speaker: Daeyeol Lee, Bloomberg Distinguished Professor of Neuroscience and Psychological and Brain Sciences, Johns Hopkins University
Time: 15:30-17:00, November 4, 2019
Location: Room 1113, Wang Kezhen Building
Abstract:
To gain insights into how the brain combines a multitude of internal and external information for generating adaptive behaviors, we investigated how the animal’s choices and their outcomes influence the activity of neurons in multiple regions of the primate cortex during probabilistic decision-making tasks. We found that neurons in the prefrontal cortex contain several different types of contextual and mnemonic information related to the animal’s choice and reward history. Consistent with the hierarchy of cortical information processing, the timescales of intrinsic and mnemonic activity gradually increased from the parietal cortex to the prefrontal cortex and the anterior cingulate cortex. Moreover, these signals were actively gated by the volatility of the animal’s environment and therefore reflected the rate of animal’s learning. These results suggest that persistent activity in the primate cortex provides a flexible mechanism for learning and decision making.
Brief bio:
Daeyeol Lee started out his higher education, in Seoul, by studying economics. Some 20 years later, he was known as one of the world’s leading neuroscientists. To bridge those two points, Lee found ways to blend principles of both disciplines — and others — to investigate the brain’s ability to make decisions.
Lee is known to many as a forefather of a niche field that’s blossomed in the past 15 years called “neuroeconomics,” which integrates not only the two disciplines it’s named for but also tools from artificial intelligence, psychology, and other areas.
After 12 years at Yale University, Lee joined Johns Hopkins University as a Bloomberg Distinguished Professor. He works primarily within the Krieger Mind/Brain Institute, and teaches neuroscience courses at the School of Medicine and the Krieger School of Arts and Sciences.
Born and raised near Seoul in South Korea, Lee earned his bachelor’s in economics at Seoul National University before he switched to the sciences and relocated to the U.S. in 1989. He earned his master’s in biology, then doctorate in neuroscience, at the University of Illinois at Urbana-Champaign, and held faculty positions at Wake Forest University and University of Rochester before joining Yale in 2006.
In addition to heading the Lee Lab at Yale, Lee has held the title of Dorys McConnell Duberg Professor of Neuroscience, and taught in the neuroscience and psychology departments.
In the world of neuroscience, Lee is known for groundbreaking experiments investigating the neural mechanisms that underlie decision-making, focusing on two areas of the brain: the prefrontal cortex and the basal ganglia. In much of his research, he has used microelectrodes to measure the activity of individual neurons in subjects as they attempt to solve complex cognitive problems.
One well-known series of studies used competitive games, similar to rock-paper-scissors, to identify the building blocks of neural signals underlying strategic decision-making and optimal learning. Some of these studies even revealed the neural basis for so-called “counterfactual outcomes,” which are closely related to emotions like regret.
Another line of Lee’s research has elucidated how the brain evaluates the value of rewards — showing, for example, the neural basis for the phenomenon of delayed gratification.
Lee also served as an editor for the Journal of Neuroscience for six years, and is currently a reviewing editor for the journal eLife. He has reached beyond academic audiences with TED Talks and a popular science book, The Birth of Intelligence, which was released in Korea in 2017 and will be published in English later this year by Oxford University Press.
Lee considered the move to Johns Hopkins a kind of indirect “homecoming,” he says, since his two most indelible mentors in neuroscience— Joseph Malpeli and Apostolos Georgopoulos— were trained here by Vernon Mountcastle, who died in 2015.
Lee says he was drawn by Hopkins’ international reputation in systems neuroscience, and the chance to work with new colleagues and resources. In particular, Lee hopes to explore new dimensions of machine learning and artificial intelligence, and to make use of cutting-edge technologies that monitor large numbers of neurons simultaneously.
Host: Dr. Lusha Zhu