Event Dates (Pacific Time):
Tuesday, February 16, 2016 - 1:00 PM to Wednesday, February 17, 2016 - 3:30 PMVenue Space:
UCSD – CNCB Large Conference Room and Applied Physics & Mathematics Annex, Room 1882
Searching for simplicity: A physicist’s quest for theories of mind and brain
Professor of Physics, Princeton University
Tuesday, February 16, 2016
1:00 pm
CNCB Large Conference Room, UC San Diego
Theoretical physics is the search for simple, compelling mathematical descriptions of the natural world. Over nearly four centuries, since Galileo, this search has been extraordinarily successful: from deep inside the atomic nucleus out to the farthest reaches of the universe, and with many stops in between, we can predict what will be seen as we look carefully at world, using our most precise instruments. Beyond the triumph of understanding, mathematical theories of the natural world give us the tools to design new devices, and are at the foundations of life changing technologies. It must be admitted, however, that one part of the world has largely evaded the grasp of theory, and this is the world of own immediate human experience: the brain and mind.
Physicists have been fascinated by the brain and mind for more than a century. Always searching for simplicity, we are challenged by the evident complexity of the cells, synapses, and myriad molecules that are the basis for our mental life. In this lecture I will survey some modern efforts to build a theoretical physics of the brain. One important theme is that our sensory systems often come close to the limits set by the laws of physics, as our eyes count single quanta of light and our ears detect vibrations smaller than the diameter of an atom. While there are many ways to build a brain that might work, there are many fewer ways to build a brain that can approach such nearly optimal performance. Perhaps, out of its complexity, the brain emerges as simpler, and more perfect, than we imagined.
Back to behavior(ism)?
Wednesday, February 17, 2016
1:00 pm
CNCB Large Conference Room, UC San Diego
The twentieth century saw (at least) two very different approached to the study of the mind. In the first half of the century, the behaviorists tried to reduce our actions to a sequence of stimulus-response relationships, while in the second half of the century the cognitive scientists focused on our internal mental life. A crucial failure of the behaviorist approach was that it posited a Markovian model of behavior—stimuli induced responses without reference to any additional hidden states. These states, literally states of mind, would become the primary concern of the cognitive scientists.
We might expect, even in the simplest of organisms, that the brain has very many internal states that are not directly observable from the outside, and hence that sequences of behaviors should be dramatically non-Markovian; a complete analysis of a seemingly simple behavior should then provide evidence for these hidden states. I’ll present a first step in this direction, using the spontaneous behavior of walking flies as an example. We’ll look at the current state of our analysis methods, the surprising combination of richness and simplicity that is revealed by these methods, and then focus on (still tentative) efforts to provide a compelling theoretical framework.
Dr. Bialek’s homepage: https://www.princeton.edu/~wbialek/wbialek.html
Come and chat with Dr. Bialek at 3:30PM!
Applied Physics & Mathematics Annex, Room 1882
