Optimality and limitations of audio-visual integration for cognitive systems

TL;DR

This paper reviews the optimality and limitations of audio-visual integration in perceptual decision-making, highlighting how computational models can produce illusions and discussing implications for designing artificial cognitive systems.

Contribution

It analyzes how the same models of multisensory integration can lead to both accurate perception and illusions, emphasizing the need for caution in artificial system design.

Findings

Multisensory integration can be statistically optimal but also produce illusions.

Computational models can account for audio-visual illusions.

Design considerations are needed to mitigate artefacts in artificial systems.

Abstract

Multimodal integration is an important process in perceptual decision-making. In humans, this process has often been shown to be statistically optimal, or near optimal: sensory information is combined in a fashion that minimises the average error in perceptual representation of stimuli. However, sometimes there are costs that come with the optimization, manifesting as illusory percepts. We review audio-visual facilitations and illusions that are products of multisensory integration, and the computational models that account for these phenomena. In particular, the same optimal computational model can lead to illusory percepts, and we suggest that more studies should be needed to detect and mitigate these illusions, as artefacts in artificial cognitive systems. We provide cautionary considerations when designing artificial cognitive systems with the view of avoiding such artefacts. Finally, we suggest avenues of research towards solutions to potential pitfalls in system design. We conclude that detailed understanding of multisensory integration and the mechanisms behind audio-visual illusions can benefit the design of artificial cognitive systems.