Multisensory decision-making in the developing and aging human brain

Imagine driving your car on a rainy night. You see an object moving sideways towards you. Your visual information is ambiguous due to the poor light and rain, thus you may also try to hear any sound this object may be making to help you identify what it is and its exact trajectory. You will have to make a decision based on what you see and hear to know whether you should swerve, speed up or hit the brakes. Your ability to make such a fast and accurate choice crucially depends on the quality of the available sensory evidence. This example highlights an important phenomenon underpinning human cognition: combining information from different senses is crucial for our ability to make perceptual decisions. Despite recent progress understanding how the brain translates the relevant multisensory information into perceptual benefits, it is unclear how the underlying neural circuits develop early in life and how ageing can affect them. To understand the neural bases of a) developmental and b) ageing influences in perceptual decision formation, it is critical that they are studied together using a consistent experimental and computational approach.

To achieve this, we will employ an audio-visual object categorisation task and will first identify the neural representations of the relevant auditory and visual evidence in the human brain. We will then use a novel methodology to quantify the interactions between these representations and their role in shaping the speed and accuracy of the participants’ perceptual choice when the two sources of information are available. We will then use the neural substrates underlying the participants’ choice to develop the first instance of a comprehensive neurally-informed cognitive model of multisensory decision-making in the developing and aging brain.