A constrained HMM-based approach to the estimation of perceptual switchingdynamics in pigeons

We describe a method for the analysis of behavioural data from experiments on perception of bistable stimuli in pigeons. The approach is based on a Hi dden Markov Model (HMM) with additional linear factorial constraints for wh ich a modified Baum-Welch algorithm is derived. It allows the estimation of the perceptual switching events, which might directly relate to transition s between states of activation of corresponding neural populations. From th e resulting time series, characteristics of the underlying perceptual dynam ics can be estimated. We also demonstrate that-inspite of the Markov assump tion-the method can reveal certain non-Markovian contributions to the dynam ics. (C) 2001 Elsevier Science B.V. All rights reserved.