Measuring Differentiation and Integrated Information to Infer Subjective Meaning and Magnitude of Consciousness
INSTITUTION: MindScope Program at the Allen Institute
PROJECT LEADERS: Anton Arkhipov, PhD, Saurabh R. Gandhi, PhD
PROJECT DURATION: 2020-2021
LAB WEBSITE: AllenInstitute.org
Conscious experiences are both integrated and differentiated; this needs to be reflected at the neuronal level. We are studying the latter characteristic of consciousness in the animal model, using large-scale two-photon calcium imaging (de Vries et al. Nature Neuroscience 2019) and Neuropixels experimental recordings (Siegle et al. Nature 2021) from the mouse visual cortex at the Allen Institute. We investigate how differentiation of neurophysiological responses is determined by properties of visual stimuli and how it differs across anatomical areas and cell types, which will inform us about the NCC (Neural Correlates of Consciousness) in the mouse visual cortex.
The content of our conscious experience varies. For example, watching a meaningful movie is very different from watching TV noise, even though both stimuli have high diversity in space and time at the level of pixels on the screen. However, for TV noise, the perceptual experience is low in complexity (it is just a “noisy pattern” from moment to moment), whereas an engaging movie evokes distinct visual percepts over time. Since percepts originate in neural activity, each specific percept must correspond to a specific pattern of activity in the neural population that supports subjective visual perception, with a 1-to-1 mapping between the two. In this project, we investigate, in the mouse model, which neuronal populations in the brain might play these roles, supporting higher or lower differentiation of the experience depending on whether the sensory stimulus is more or less meaningful.
Broader Impact:
This project aims to shed light on which populations of neurons in neocortex support conscious perception of meaningful stimuli. This knowledge will be fundamental for our understanding of how different components of the brain contribute to generating consciousness and specific contents of consciousness. Ultimately, such understanding will be necessary for better treatment of consciousness disorders and for more effective, targeted therapies.
List of Publications
William GP, Mayner et al. (2022) Measuring Stimulus-Evoked Neurophysiological Differentiation in Distinct Populations of Neurons in Mouse Visual Cortex. eNeuro doi: 10.1523/ENEURO.0280-21.2021
Gandhi SR et al. (2022) A survey of neurophysiological differentiation across mouse visual brain areas and timescales. bioRxiv https://doi.org/10.1101/2022.01.21.476869