Stochastic Accumulation by Cortical Columns May Explain the Scalar Property of Multistable Perception

Publication Type:

Journal Article

Source:

Physical Review Letters, Volume 113, Issue 9, p.098103 (2014)

URL:

http://link.aps.org/doi/10.1103/PhysRevLett.113.098103

Abstract:

The timing of certain mental events is thought to reflect random walks performed by underlying neural dynamics. One class of such events—stochastic reversals of multistable perceptions—exhibits a unique scalar property: even though timing densities vary widely, higher moments stay in particular proportions to the mean. We show that stochastic accumulation of activity in a finite number of idealized cortical columns—realizing a generalized Ehrenfest urn model—may explain these observations. Modeling stochastic reversals as the first-passage time of a threshold number of active columns, we obtain higher moments of the first-passage time density. We derive analytical expressions for noninteracting columns and generalize the results to interacting columns in simulations. The scalar property of multistable perception is reproduced by a dynamic regime with a fixed, low threshold, in which the activation of a few additional columns suffices for a reversal.