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Rufin VanRullen

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CerCo (online) Conference on April 16th @9am | Randall O'Reilly

CerCo Conference - Friday, 16 April 2021, 9:00 AM
Title: Predictive Error-driven Learning in the Brain
Speaker: Randall O'Reilly (Center for Neuroscience, University of California Davis)

Abstract: How do humans learn from raw sensory experience?  Throughout life, but most obviously in infancy, we learn without explicit instruction.  We propose a detailed biological mechanism for the widely-embraced idea that learning is driven by the differences between predictions and actual outcomes (i.e., predictive error-driven learning).  Specifically, numerous weak projections into the pulvinar nucleus of the thalamus generate top-down predictions, and sparse, focal driver inputs from lower areas supply the actual outcome, originating in layer 5 intrinsic bursting (5IB) neurons.  Thus, the outcome representation is only briefly activated, roughly every 100 ms (i.e., 10 Hz, alpha), resulting in a temporal difference error signal, which drives local synaptic changes throughout the neocortex.  This results in a biologically-plausible form of error backpropagation learning.  We implemented these mechanisms in a large-scale model of the visual system, and found that the simulated inferotemporal (IT) pathway learns to systematically categorize 3D objects according to invariant shape properties, based solely on predictive learning from raw visual inputs.  These categories match human judgments on the same stimuli, and are consistent with neural representations in IT cortex in primates.  The same learning mechanisms apply to sensory-motor predictive learning, and are being tested in an immersive rodent-level navigation and foraging environment, and in speech perception and production.

Zoom link:
https://univ-tlse3-fr.zoom.us/j/8504047 … ZPWm02QT09

Meeting ID: 850 4047 0167
Passcode: 616413