Periodic Reporting for period 3 - GenPercept (Spatio-temporal mechanisms of generative perception)
Okres sprawozdawczy: 2022-06-01 do 2023-11-30
A long-standing mystery to neuroscientists is how perceptual systems rapidly and effortlessly compute a vivid and veridical representation of the external world from the noisy and ambiguous input furnished by our sensory systems. 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 regularly updates this model from current sensory data. This classic idea has been well formulised within the modern framework of Generative Bayesian Inference, but the mechanisms remain poorly understood, both from a functional and neural point of view.
GenPercept aims to establish the fundamental importance of generative processes in perception, characterise quantitatively their functional role, and describe their underlying neural mechanisms, exploiting state-of-the-art psychophysical, EEG, imaging and pupillometry techniques. In particular it will explore the innovative idea that neural oscillations reflect reverberations in the propagation of generative prediction and error signals, and study individual differences, particularly in autistic perception, where generative mechanisms show interesting atypicalities.
Fully understanding generative processes should lead to a deep understanding of how we perceive and interact with the world, and how past perceptual experience influences what we perceive.
GenPercept aims to establish the fundamental importance of generative processes in perception, characterise quantitatively their functional role, and describe their underlying neural mechanisms, exploiting state-of-the-art psychophysical, EEG, imaging and pupillometry techniques. In particular it will explore the innovative idea that neural oscillations reflect reverberations in the propagation of generative prediction and error signals, and study individual differences, particularly in autistic perception, where generative mechanisms show interesting atypicalities.
Fully understanding generative processes should lead to a deep understanding of how we perceive and interact with the world, and how past perceptual experience influences what we perceive.
The project is proceeding extremely well, exceeding expectations. With a multi-disciplinary approach, we have been able to demonstrate the functional importance of serial dependence, and model predictive behaviour under many conditions within a Bayesian framework, with a detailed Kalman filter-based model.
A very important prediction of the project was that neural oscillations constitute an important mechanism in communicating perceptual expectations. We have shown this in the auditory domain, with an “ear-of-origin” task, and in vision for identification of gender. Furthermore we have exploited high-field fMRI to record clear neural signatures of the oscillatory communication between visual and motor cortices.
Finally, we have looked at individual differences in the way people use expectations and other contextual information, and find are strong negative correlation with autistic-like personality traits (AQ): people with high AQ show less reliance on contextual information.
Our research has been presented to the scientific community at the main international conferences of the field (including The Vision Sciences Society annual meeting, the European Conference of Visual Perception, International Society for Magnetic Resonance in Medicine).
It has been disseminated in several public events, including the Researchers’ Bright Night 2020 and 2021, and a public communication event Brainforum in Milan, https://www.brainforum.it/speaker/burr-david/.
It has received a good deal of national and international press coverage, outlined in section Media Coverage on web site www. https://www.genpercept.eu/. And the PI received a prestigious award from the British Consulate in Milan “GREAT Research Made in Italy Award” Italy-United Kingdom.
A very important prediction of the project was that neural oscillations constitute an important mechanism in communicating perceptual expectations. We have shown this in the auditory domain, with an “ear-of-origin” task, and in vision for identification of gender. Furthermore we have exploited high-field fMRI to record clear neural signatures of the oscillatory communication between visual and motor cortices.
Finally, we have looked at individual differences in the way people use expectations and other contextual information, and find are strong negative correlation with autistic-like personality traits (AQ): people with high AQ show less reliance on contextual information.
Our research has been presented to the scientific community at the main international conferences of the field (including The Vision Sciences Society annual meeting, the European Conference of Visual Perception, International Society for Magnetic Resonance in Medicine).
It has been disseminated in several public events, including the Researchers’ Bright Night 2020 and 2021, and a public communication event Brainforum in Milan, https://www.brainforum.it/speaker/burr-david/.
It has received a good deal of national and international press coverage, outlined in section Media Coverage on web site www. https://www.genpercept.eu/. And the PI received a prestigious award from the British Consulate in Milan “GREAT Research Made in Italy Award” Italy-United Kingdom.
The projected has progressed well beyond the state of the art, in the ways explained above. In the second half of the project we plan to continue this approach, tackling some of the more difficult proposed experiments of WP3, measuring predicted effects during eye- and body-movements. These experiments will be time-consuming, but we expect they will yield very important results.
We will also follow up on our unexpected result of the pupil light reflex being modulated by the numerosity of objects in the scene. We expect this technique will prove extremely useful in studying phenomena like adaptation.
And we will continue to look for individual differences in the exploitation of generative perception, particularly in relation to autism and autistic-like traits.
We will also follow up on our unexpected result of the pupil light reflex being modulated by the numerosity of objects in the scene. We expect this technique will prove extremely useful in studying phenomena like adaptation.
And we will continue to look for individual differences in the exploitation of generative perception, particularly in relation to autism and autistic-like traits.