title: A Bayesian Perspective on Accumulation in the Magnitude System.
abstract: Several theoretical and empirical work posit the existence of a common magnitude system in the brain. Such a proposal implies that manipulating stimuli in one magnitude dimension (e.g. duration in time) should interfere with the subjective estimation of another magnitude dimension (e.g. size in space). Here, we asked whether a generalized Bayesian magnitude estimation system would sample sensory evidence using a common, amodal prior. Two psychophysical experiments separately tested participants on their perception of duration, surface, and numerosity when the non-target magnitude dimensions and the rate of sensory evidence accumulation were manipulated. First, we found that duration estimation was resilient to changes in surface and numerosity, whereas lengthening (shortening) the duration yielded under- (over-) estimations of surface and numerosity. Second, the perception of surface and numerosity were affected by changes in the rate of sensory evidence accumulation, whereas duration was not. Our results suggest that a generalized magnitude system based on Bayesian computations would minimally necessitate multiple priors.
authors.affiliation: CEA, DRF/I2BM, NeuroSpin, INSERM, U992, Cognitive Neuroimaging Unit, Université Paris-Sud, Université Paris-Saclay, F-Gif/Yvette, France.
authors.forename: Benoît
authors.initials: B
authors.lastname: Martin
authors.affiliation: Department of Psychology, George Mason University, Fairfax, VA, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Wiener
authors.affiliation: CEA, DRF/I2BM, NeuroSpin, INSERM, U992, Cognitive Neuroimaging Unit, Université Paris-Sud, Université Paris-Saclay, F-Gif/Yvette, France. virginie.van.wassenhove@gmail.com.
authors.forename: Virginie
authors.identifier: http://orcid.org/0000-0002-2569-5502
authors.initials: V
authors.lastname: van Wassenhove