Document Type

Article

Disciplines

1.1 MATHEMATICS, Neuroscience

Abstract

The brain seamlessly integrates signals from multiple sensory modalities to interpret the world efficiently. By using information from various senses, the brain can enhance its ability to detect and respond to stimuli more quickly and accurately. However, combining sensory cues from multiple modalities is only sometimes beneficial as it may lead to illusions and reduced behavioural performance. Behavioural and electrophysiological experiments have revealed that detection and decision-making strategies for multisensory cues evolve throughout human development and ageing. Additionally, studies have demonstrated that maladaptive multisensory processing is a key indicator of a proclivity to falls in older adults and individuals with Parkinson’s Disease. Therefore, it is imperative to develop models of cortical connections between sensory areas involved in detection and decision-making to elucidate the breakdowns associated with these pathologies. The models developed in this thesis investigate cortical connections and multisensory mechanisms in sensory accumulation areas across healthy human development and individuals with various pathologies. This document presents an adaptable modelling framework of multisensory accumulation by extending the two-variable decision-making recurrent cortical model from Wong and Wang (2006). Until now, research involving cortical decision-making models has been primarily unisensory. The leading theories on multisensory integration inform the multisensory mechanisms used in this thesis, including a winner-take-all sensory response mechanism, vii linear summation co-activation strategy, and the inclusion of multisensory units in the model. The results of this dissertation also underscore the importance of examining the effects of trial sequences in multisensory experiments. All models reproduce behavioural measures from multisensory detection and decision-making tasks. Assessing distinct model architectures and multisensory integration strategies, the findings presented in this text suggest the presence of co-activation in the decision-making areas of the human brain during simple multimodal tasks. Furthermore, this dissertation demonstrates how biologically motivated mathematical models can be used to investigate the potential mechanisms underlying the observed differences in unisensory and multisensory responses.

DOI

https://doi.org/10.21427/gcvq-wj12

Creative Commons License

Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.

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