Common phenomenal and neural substrate geometry in visual motion perception
- 1School of Psychological Sciences, Faculty of Medicine, Nursing and Health Science, Monash University, Victoria, Australia; Berlin School of Mind and Brain, Faculty of Philosophy, Humboldt-Universität zu Berlin, Berlin, Germany; Department of Psychiatry, University of Wisconsin-Madison, Madison, USA. Electronic address: [email protected]
- 2School of Psychological Sciences, Faculty of Medicine, Nursing and Health Science, Monash University, Victoria, Australia
- 3Division of Visual Information Processing, National Institute for Physiological Sciences, Okazaki, Japan; Physiological Sciences Program, Graduate Institute for Advanced Studies, Sokendai, Okazaki, Japan
Abstract
What is a possible physical substrate of the qualitative aspects of consciousness (qualia)? Answering this question is a central goal of consciousness research. Due to their subjective and ineffable nature, finding a quantitative way to characterise qualia from verbal description has thus far proven elusive. To overcome the challenge of expressing subjective experience, recent structural and relational approaches have been proposed from mathematics. Yet, as far as we know, no attempts have been made to evaluate the relationship between a certain structure of qualia and the structure of a candidate underlying physical substrate. Towards this ambitious goal of linking the structures of qualia and physical, we set out to make an empirical first step by focusing on experienced dissimilarity of visual motion in human participants and stimulus-evoked neural population response geometry recorded from mouse primary visual cortex. From human participants (N=171), we obtained dissimilarity ratings of visual motion experiences induced by 48 stimuli, spanning across 8 directions and 6 spatial frequencies. Analysis revealed a human dissimilarity structure that was not well captured by a simple monotonic function of physical motion-direction difference alone nor by a pure orientation-symmetry account. From nine individual mice, we recorded single-neuron activity (n=751) with optical imaging in both awake and lightly anaesthetised conditions (isoflurane 0.6-0.8%). From neuron population responses to a similar set of motion stimuli, we computed a distance matrix that is comparable to our human dissimilarity matrix. Quantitative analyses show structural commonalities between a human dissimilarity structure and mouse neural structure, where a categorical organisation of stimulus direction best explained both. These commonalities were similar in awake and anaesthetised recordings, suggesting that this coarse V1 geometry is relatively insensitive to this type of anaesthesia; future work combining behaviour with causal intervention is required to relate such neural structures to conscious experience. Finally, we list several empirical factors that can be improved to promote our qualia structure approach in the future. Graphical Abstract Similarity structures derived from a pairwise similarity rating task in humans revealed a mismatch between physical stimuli and subjective experience of similarity of visual motion: participants robustly rated their experience of opposite direction stimuli as similar. In mice, we used 2-photon Ca2+ imaging to record the activity of c.80 neurons per mouse in the primary visual cortex (V1) of nine mice. By computing a correlation matrix that records the similarity of responses to the same pairwise comparisons as in humans across all neurons, we can then represent neuronal ‘distance’. This revealed that mice neurons also exhibited the same dissociation between physical stimuli and responses as in humans at lower spatial frequencies. By comparing these dissimilarity and distance matrices using linear mixed effects modelling, we showed that a categorical model, not direction or orientation, best explains both human and mice data. Ultimately, this study is a methodological proof-of-concept for comparing structures of experience to candidate structures of a possible neural substrate in order to constrain their candidacy. Highlights Visual motion feels more similar for opposite than diagonal directions Pairwise similarity ratings reveal structure of visual motion experience Human motion experience and mouse visual cortex share a common geometry Mouse visual cortex codes motion similarly when awake and lightly anaesthetised
Related
- Probing the neural geometry of conscious object perception in time
- Cross-Frequency Coupling as a Neural Substrate for Prediction Error Evaluation: A Laminar Neural Mass Modeling Approach
- Mapping the neural basis of the perception of “flow of time”: interval timing and mental time travel in the human brain
- Repeated visual adaptation induces persistent behavioral and neural biases in body size perception
- A Bio-Plausible Visual Neural Network for Locust-Inspired Collision Perception
BibTeX
@article{robinson2026common,
title = {{Common phenomenal and neural substrate geometry in visual motion perception}},
author = {Kallum Robinson and Ariel Zeleznikow-Johnston and Jiahao Wu and Yumiko Yoshimura and Naotsugu Tsuchiya},
journal = {NeuroImage},
year = {2026},
month = oct,
doi = {10.1016/j.neuroimage.2026.122313},
url = {https://doi.org/10.1016/j.neuroimage.2026.122313},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Common phenomenal and neural substrate geometry in visual motion perception
AU - Kallum Robinson
AU - Ariel Zeleznikow-Johnston
AU - Jiahao Wu
AU - Yumiko Yoshimura
AU - Naotsugu Tsuchiya
PY - 2026
DA - 2026/10/24
JO - NeuroImage
DO - 10.1016/j.neuroimage.2026.122313
UR - https://doi.org/10.1016/j.neuroimage.2026.122313
AB - What is a possible physical substrate of the qualitative aspects of consciousness (qualia)? Answering this question is a central goal of consciousness research. Due to their subjective and ineffable nature, finding a quantitative way to characterise qualia from verbal description has thus far proven elusive. To overcome the challenge of expressing subjective experience, recent structural and relational approaches have been proposed from mathematics. Yet, as far as we know, no attempts have been made to evaluate the relationship between a certain structure of qualia and the structure of a candidate underlying physical substrate. Towards this ambitious goal of linking the structures of qualia and physical, we set out to make an empirical first step by focusing on experienced dissimilarity of visual motion in human participants and stimulus-evoked neural population response geometry recorded from mouse primary visual cortex. From human participants (N=171), we obtained dissimilarity ratings of visual motion experiences induced by 48 stimuli, spanning across 8 directions and 6 spatial frequencies. Analysis revealed a human dissimilarity structure that was not well captured by a simple monotonic function of physical motion-direction difference alone nor by a pure orientation-symmetry account. From nine individual mice, we recorded single-neuron activity (n=751) with optical imaging in both awake and lightly anaesthetised conditions (isoflurane 0.6-0.8%). From neuron population responses to a similar set of motion stimuli, we computed a distance matrix that is comparable to our human dissimilarity matrix. Quantitative analyses show structural commonalities between a human dissimilarity structure and mouse neural structure, where a categorical organisation of stimulus direction best explained both. These commonalities were similar in awake and anaesthetised recordings, suggesting that this coarse V1 geometry is relatively insensitive to this type of anaesthesia; future work combining behaviour with causal intervention is required to relate such neural structures to conscious experience. Finally, we list several empirical factors that can be improved to promote our qualia structure approach in the future. Graphical Abstract Similarity structures derived from a pairwise similarity rating task in humans revealed a mismatch between physical stimuli and subjective experience of similarity of visual motion: participants robustly rated their experience of opposite direction stimuli as similar. In mice, we used 2-photon Ca2+ imaging to record the activity of c.80 neurons per mouse in the primary visual cortex (V1) of nine mice. By computing a correlation matrix that records the similarity of responses to the same pairwise comparisons as in humans across all neurons, we can then represent neuronal ‘distance’. This revealed that mice neurons also exhibited the same dissociation between physical stimuli and responses as in humans at lower spatial frequencies. By comparing these dissimilarity and distance matrices using linear mixed effects modelling, we showed that a categorical model, not direction or orientation, best explains both human and mice data. Ultimately, this study is a methodological proof-of-concept for comparing structures of experience to candidate structures of a possible neural substrate in order to constrain their candidacy. Highlights Visual motion feels more similar for opposite than diagonal directions Pairwise similarity ratings reveal structure of visual motion experience Human motion experience and mouse visual cortex share a common geometry Mouse visual cortex codes motion similarly when awake and lightly anaesthetised
SN - 1053-8119
SN - 1095-9572
ER -