Sources of noise during accumulation of evidence in unrestrained and voluntarily head-restrained rats.

Publication Year
2015

Type

Journal Article
Abstract

Decision-making behavior is often characterized by substantial variability, but its source remains unclear. We developed a visual accumulation of evidence task designed to quantify sources of noise and to be performed during voluntary head restraint, enabling cellular resolution imaging in future studies. Rats accumulated discrete numbers of flashes presented to the left and right visual hemifields and indicated the side that had the greater number of flashes. Using a signal-detection theory-based model, we found that the standard deviation in their internal estimate of flash number scaled linearly with the number of flashes. This indicates a major source of noise that, surprisingly, is not consistent with the widely used 'drift-diffusion modeling' (DDM) approach but is instead closely related to proposed models of numerical cognition and counting. We speculate that this form of noise could be important in accumulation of evidence tasks generally.

Journal
Elife
Volume
4
Pages
e11308
Date Published
2015 Dec 17
ISSN Number
2050-084X
Alternate Journal
Elife
PMCID
PMC4749559
PMID
26673896