Periodic Reporting for period 3 - PUPILTRAITS (Biomarkers of individual differences in human cortical visual processing)
Periodo di rendicontazione: 2022-03-01 al 2023-08-31
Perception is never a record of reality; it is best described as an inference, where incomplete sensory data is pondered against its spatiotemporal context. Since the context varies depending on the history of stimulation, our inferences often differ between and within individuals. There is evidence that autistic persons use context less than non-autistic persons, both in perception and in other domains. Finding how complex ideas like inference and context map onto the activity of neurons is one of the main goals of neuroscience. Understanding how these vary across persons, particularly on the autistic spectrum, could mark a key step towards characterizing each person’s style of information processing – the first step towards communicating and interacting. Finding whether and how information processing varies within individuals, time locked to metabolic changes, has the potential to elucidate the much-discussed links between brain and gut function. Project PUPILTRAITS addresses these questions using the visual system as a model, taking advantage of the in-depth physiological knowledge and the established methods for quantifying visual perception: psychophysics, and ultra-high field functional Magnetic Resonance, complemented with the novel pupillometric technique.
Thanks to the diverse expertise of the PUPILTRAITS team members, we were able to apply a variety of non-invasive techniques (eye-tracking, psychophysics, MRI, EEG) to the study of human participants of different ages and clinical profiles.
We substantiated the main novel concept of the project, that pupil diameter reflects the way we process information. We demonstrated this in a variety of domains: perception, attention, and cognition. We were able to show a tight relationship between performance and Autistic Traits, supporting the notion that individual styles of information-processing can be indexed through pupil-size: a simple, objective, and quantitative measure. The area of applicability of this technique is rapidly growing, as we (and other teams) expose the normed relationship between changes in pupil diameter and information processing in the brain. Using neuroimaging, we are gaining insight into mechanisms through which sensory signals are evaluated against their context, which is variable across individuals and over time. We also gathered initial evidence that the metabolic state (long-term, like obesity) impacts basic functions of the visual system.
The work we performed in the first half of the project has been reported in 22 peer-reviewed publications (14 from studies that directly stemmed from the project, 4 of which in journals with IF > 8, and an additional eight related publications). Our research was 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 was disseminated in public events, including the Researchers’ Bright Night 2020 and a speech at the opening ceremony of the 2021-22 Academic Year of the University of Pisa, in the presence of the President of the Republic and the Ministry of University and Research.
We substantiated the main novel concept of the project, that pupil diameter reflects the way we process information. We demonstrated this in a variety of domains: perception, attention, and cognition. We were able to show a tight relationship between performance and Autistic Traits, supporting the notion that individual styles of information-processing can be indexed through pupil-size: a simple, objective, and quantitative measure. The area of applicability of this technique is rapidly growing, as we (and other teams) expose the normed relationship between changes in pupil diameter and information processing in the brain. Using neuroimaging, we are gaining insight into mechanisms through which sensory signals are evaluated against their context, which is variable across individuals and over time. We also gathered initial evidence that the metabolic state (long-term, like obesity) impacts basic functions of the visual system.
The work we performed in the first half of the project has been reported in 22 peer-reviewed publications (14 from studies that directly stemmed from the project, 4 of which in journals with IF > 8, and an additional eight related publications). Our research was 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 was disseminated in public events, including the Researchers’ Bright Night 2020 and a speech at the opening ceremony of the 2021-22 Academic Year of the University of Pisa, in the presence of the President of the Republic and the Ministry of University and Research.
In the second half of the project, we plan to investigate the neural substrates of trait- and state-variability of perceptual processing. Building on the results of the first half of the project, our test-cases will be ASD and metabolism, studied through combined pupillometric, psychophysical and brain imaging techniques.