Brains, Minds + Machines Seminar Series: Apical dendrites as a site for gradient calculations

Photo of Blake Richards
April 26, 2019 - 4:00 pm to 5:00 pm
Speaker/s: 

Blake Richards, Assistant Professor, Associate Fellow of the Canadian Institute for Advanced Research (CIFAR)

Organizer: 

Abstract: 

Theoretical and empirical results in the neural networks literature demonstrate that effective learning at a real-world scale requires changes to synaptic weights that approximate the gradient of a global loss function. For neuroscientists, this means that the brain must have mechanisms for communicating loss gradients between regions, either explicitly or implicitly. Here, I describe our research into potential means of communicating loss gradients using the unique properties of apical dendrites in pyramidal neurons. I will present modelling work showing that, in principle, ensembles of pyramidal neurons could using the temporal derivative of their activity to estimate cost gradients. I will also show how this can be learned using the discontinuities that spikes induce. Finally, I will discuss specific experimental predictions that arise from these theories.

 

This event is co-organized by the CBMM Trainee Leadership Council.

Details

MIT Bldg 46-3002, 43 Vassar Street, Cambridge MA 02139
Date: 
April 26, 2019
Time: 
4:00 pm to 5:00 pm
Venue: 
Singleton Auditorium(46-3002)
Address: 

MIT Bldg 46-3002, 43 Vassar Street, Cambridge MA 02139