Year: 2026
Type: preprint
Abstract: Observing an object under different viewing conditions, in spite of substantial variability in the image structures when changing the distance or the viewing direction relative to the object, we can maintain the identity of the object. How does the vision system cope with this variability, that will substantially influence the receptive field responses? One hypothesis is that the receptive field family should be covariant under geometric image transformations and thereby have variabilities in the shapes of the receptive fields corresponding to the degrees of freedom of the geometric image transformations. Specifically, it has been predicted that the receptive fields should have a variability in the degree of elongation, corresponding to varying the slant angle when observing local surface patches. Such a variability has also been predicted from indirect support in terms of variabilities in the orientation selectivity properties in V1 for monkeys and cats, which by a theoretical model has been linked to variabilities in the elongation of the receptive fields. In this paper, we measure such variabilities in receptive field shapes in a more direct way, by reconstructing receptive fields from calcium imaging experiments for mice previously performed by the Allen Institute. Our findings reveal a variability in the degree of elongation that exceeds what measurement noise produces, spanning about a factor of 5, thereby showing that the predictions that were made for higher mammals with orientation maps, such as primates and cats, also apply to a species without orientation maps, with its primary visual cortex instead based on a salt-and-pepper organization of the receptive fields. Author summary The primary visual cortex contains cells that each respond to a small patch of the visual scene. For the visual system to recognise that two different views of the same object belong together, these cells must come in a range of shapes that between them cover the ways an image can change as we, or the objects around us, move. A mathematical theory of vision predicts which shapes should be present, and in particular that the cells should vary in how elongated they are. That prediction had only been tested indirectly, in animals such as cats and monkeys whose visual cortex is arranged into orderly maps of shape preference. We tested for this hypothesis by more direct means for the mouse, whose visual cortex has no such map, by fitting a mathematical model to visual cortex neurons recorded in a large public dataset. Among the cells we could confirm as the simplest type, the degree of elongation varied by more than measurement noise alone can produce, spanning roughly a factor of five, scattered across the cortex with no orderly arrangement.
Institution: KTH Royal Institute of Technology
Language: English
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7213917070