Of Rodents and Primates: Comparative Decision Making

Seminar | September 4 | 12-1:30 p.m. | 560 Evans Hall

 Pam Reinagel, UC San Diego

 Neuroscience Institute, Helen Wills

In rapid sensory decision-making, the time taken to choose and the accuracy of the choice are related in three distinct ways. First, it takes more time to assess noisy signals, so decisions about weak sensory stimuli are slower, as well as less accurate. Second, for any given stimulus strength, adopting an overall policy of higher stringency will make decisions slower, but more accurate. Third, even when stimulus strength and stringency are the same, reaction time is extremely variable from trial to trial; the literature from humans an monkeys reports that reaction time is anti-correlated with accuracy: later responses are less accurate. The first two facts are easily explained by the Bounded Drift Diffusion Model. The third is not – but multiple competing models can account for it, such as collapsing decision bounds or urgency signals. In this talk, I will present data that rodents are the same as primates in the first two respects, but opposite in the third: for rodents, later responses are more accurate. I will show that at least one model can parsimoniously account for both primate and rodent behavior. Fitting both species in one model provides insight into what is conserved and what differs, when it comes to the decisions of mice and men.
Related background: Reinagel, P (2013) Speed and accuracy of visual motion discrimination by rats. PLoS-ONE 8(6):e68505 . https://doi.org/10.1371/journal.pone.0068505