Periodic Reporting for period 4 - GenPercept (Spatio-temporal mechanisms of generative perception)
Période du rapport: 2023-12-01 au 2024-05-31
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. Most neuroscientists now agree that problem is in part solved by the fact that the brain does not process all incoming sensory information anew, but generates a model of the world from past experience, and regularly updates this model from current sensory data. This classic idea has recently 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.
The objectives of GenPercept were to demonstrate the fundamental importance of generative processes in perception, showing how they lead to efficient perceptual processes. It proposed to characterise quantitatively their functional role, then go on to explore the underlying neural mechanisms, exploiting state-of-the-art psychophysical, EEG, imaging and pupillometry techniques. A major goal was to explore the innovative idea that neural oscillations reflect reverberations in the propagation of generative prediction and error signals. All of the objectives have been realized.
The major importance of the study is to science, increasing our understanding of how we perceive and interact with the world, and how past perceptual experience influences what we perceive. There are no immediate clinical or societal benefits, but in the long term, increasing basic understanding in this area can benefit many fields, from ophthalmology to neurology, and even computer science and robotics.
The objectives of GenPercept were to demonstrate the fundamental importance of generative processes in perception, showing how they lead to efficient perceptual processes. It proposed to characterise quantitatively their functional role, then go on to explore the underlying neural mechanisms, exploiting state-of-the-art psychophysical, EEG, imaging and pupillometry techniques. A major goal was to explore the innovative idea that neural oscillations reflect reverberations in the propagation of generative prediction and error signals. All of the objectives have been realized.
The major importance of the study is to science, increasing our understanding of how we perceive and interact with the world, and how past perceptual experience influences what we perceive. There are no immediate clinical or societal benefits, but in the long term, increasing basic understanding in this area can benefit many fields, from ophthalmology to neurology, and even computer science and robotics.
The project has proceeded 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, using both psychophysical and EEG techniques. Furthermore we have exploited high-field fMRI to record clear neural signatures of the oscillatory communication between visual and motor cortices.
We have looked at individual differences in the way people use expectations and other contextual information, and find a 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, using both psychophysical and EEG techniques. Furthermore we have exploited high-field fMRI to record clear neural signatures of the oscillatory communication between visual and motor cortices.
We have looked at individual differences in the way people use expectations and other contextual information, and find a 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. It has established that generative perception is efficient, highly beneficial for perception. We have showed how past perceptual history is communicated through oscillatory neural activity; and we have demonstrated the strong interplay between predictive perception, and action.