A constrained HMM-based approach to the estimation of perceptual switching dynamics 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 Hidden Markov Model (HMM) with additional linear factorial constraints for which a modified Baum-Welch algorithm is derived. It allows the estimation of the perceptual switching events, which might directly relate to transitions between states of activation of corresponding neural populations. From the resulting time series, characteristics of the underlying perceptual dynamics can be estimated. We also demonstrate that-inspite of the Markov assumption-the method can reveal certain non-Markovian contributions to the dynamics. (C) 2001 Elsevier Science B.V. All rights reserved.