Project description
Neural substrates of the Bayesian model of sensory perception
All day long, we are bombarded with a barrage of sensory inputs. These processes may be streamlined via a model our brain creates of our world, updated with experience and used to make predictions affecting our output. Recently, this idea has been revisited in the application of Bayesian theories, proposed to describe both healthy sensory perception as well as the impaired predictive ability associated with high-functioning autism. GenPercept is looking for neural mechanisms in both normal sensory processing and neuropsychiatric disorders with a focus on saccades and rhythmic oscillations in brain activity. Scientists hope to find the neural substrate implicated in our response to how the past influences our present perception.
Objective
How do we rapidly and effortlessly compute a vivid veridical representation of the external world from the noisy and ambiguous input supplied by our sensors? One possibility is that the brain does not process all incoming sensory information anew, but actively generates a model of the world from past experience, and uses current sensory data to update that model. This classic idea has been well formulised within the modern framework of Generative Bayesian Inference. However, despite these recent theoretical and empirical advances, there is no definitive proof that generative mechanisms prevail in perception, and fundamental questions remain.
The ambitious aim of GenPercept is to establish the importance of generative processes in perception, characterise quantitatively their functional role, and describe their underlying neural mechanisms. With innovative psychophysical and pupillometry techniques, it will show how past perceptual experience is exploited to manage and mould sensory analysis of the present. With ultra-high field imaging, it will identify the underlying neural mechanisms in early sensory cortex. With EEG and custom psychophysics it will show how generative predictive mechanisms mediate perceptual continuity at the time of saccadic eye movements, and explore the innovative idea that neural oscillations reflect reverberations in the propagation of generative prediction and error signals. Finally, it will look at individual differences, particularly in autistic perception, where generative mechanisms show interesting atypicalities.
A full understanding of generative processes will lead to fundamental insights in understanding how we perceive and interact with the world, and how past perceptual experience influences what we perceive. The project is also of clinical relevance, as these systems are prone to dysfunction in several neuro-behavioural conditions, including autism spectrum disorder.
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Funding Scheme
ERC-ADG - Advanced GrantHost institution
50121 Florence
Italy