Christopher Summerfield, P.I.
Professor of Experimental Psychology & Cognitive Neuroscience,
Oxford University

A Normative Account of Irrational Human Perceptual Decisions

Psychophysics and sensory neuroscience are dominated by the view that judgments about sensory stimuli are limited by noise that arises during sensory encoding.  However, cognitive scientists have long emphasized that decisions are limited by capacity - i.e. by noise that arises during sequential integration of information, or corrupts inferential processes that occur at the decision stage. In cognitive and economic tasks, these biases lead to "irrational" decisions, i.e. those that are sensitive to irrelevant contextual information and fail to maximize outcomes. I will discuss a number of behavioral experiments showing that human judgments about the sensory world are similarly irrational, exhibiting confirmatory biases and reversing with irrelevant contextual factors, and neural experiments that pinpoint the locus of these biases.  However, using computational simulations, I will go on to provide a normative account for irrational biases, showing that under limited capacity, the decision policies adopted by humans discard information but paradoxically maximize reward in the face of noise arising during mental inference.

This lecture is made possible by a generous Endowment by the family of Allen. L. Edwards.