Bifurcation study of a neural field competition model with an application to perceptual switching in motion integration

Abstract

Perceptual multistability is a phenomenon in which alternate interpretations of a fixed stimulus are perceived intermittently. Although correlates between activity in specific cortical areas and perception have been found, the complex patterns of activity and the underlying mechanisms that gate multistable perception are little understood. Here, we present a neural field competition model in which competing states are represented in a continuous feature space. Bifurcation analysis is used to describe the different types of complex spatio-temporal dynamics produced by the model in terms of several parameters and for different inputs. The dynamics of the model was then compared to human perception investigated psychophysically during long presentations of an ambiguous, multistable motion pattern known as the barberpole illusion. In order to do this, the model is operated in a parameter range where known physiological response properties are reproduced whilst also working close to bifurcation. The model accounts for characteristic behaviour from the psychophysical experiments in terms of the type of switching observed and changes in the rate of switching with respect to contrast. In this way, the modelling study sheds light on the underlying mechanisms that drive perceptual switching in different contrast regimes. The general approach presented is applicable to a broad range of perceptual competition problems in which spatial interactions play a role.

Rich spectrum of neural field dynamics in the presence of short-term synaptic depression

“…Bifurcation analysis has provided important insights into the neural field dynamics, indicating underlying mechanisms for a variety of dynamical behaviors. In [44], a similar neural field model with linear spike frequency adaptation was studied with detailed bifurcation analysis. In the presence of a simple weak input, their model also shows static bumps, moving bumps, and sloshers.…”

Self-Induced Switchings between Multiple Space-Time Patterns on Complex Networks of Excitable Units

“…• As a third mechanism, we mention the adaptation to an external signal, which is extensively discussed with respect to perception processes in the brain [37]. Here, the basic assumption is that either the adaptation to a time-dependent stimulus [59] or the competition between different activity regimes for a fixed stimulus [60] gives rise to an intermittent switching between different neuronal patters.…”

The uncoupling limit of identical Hopf bifurcations with an application to perceptual bistability

“…Models of perceptual bistability have successfully captured the dynamics of perceptual switching [24,49,50], the dependence of these dynamics on stimulus parameters [24,31,42,39], mechanisms for attention [28], entrainment to slowly varying stimuli [22] and the effects of stimulus perturbations [38]. Generally models are based on competition between abstract, percept-based units [49,43,18,28], but more recently models with a featurebased representation of competition have been developed [24,20,37,39]. Some perceptbased models have explored how rapidly alternating inputs (>2 Hz) can still give rise to stable perception over several seconds [50,46,28].…”