Rats and Humans can Optimally Accumulate Evidence for Decision-making

Bingni W. Brunton, Matthew M. Botvinick, Carlos D. Brody, Science, 340:95-98 (2013).

Where do imperfections in decision-making come from? And can rats perform gradual accumulation of evidence for decision-making, like primates do? This paper describes  a decision-making task that is particularly well-suited to detailed quantitative modeling and analysis. Using this task together with a trial-by-trial model of the behavior, first-author Bing Brunton showed that rats, like humans, can gradually accumulate evidence for decision-making, and that their evidence accumulator is optimal in the sense of being noiseless and lossless. Thus imperfections in decision-making all came from imperfections in sensory processing, none from the evidence accumulation process.The modeling and analysis methods Bing developed are the most statistically powerful approach to date for characterizing properties of decision-making processes. The approach can be readily applied to other decision-making tasks and modalities, and provides a moment-by-moment, trial-by-trial estimate of the subject’s internal estimate of the accumulating evidence.

Nature published a News and Views piece on our paper.

First-author Bing Brunton is now faculty at the University of Washington, Seattle.