title: Cortical spatiotemporal dimensionality reduction for visual grouping.
abstract: The visual systems of many mammals, including humans, are able to integrate the geometric information of visual stimuli and perform cognitive tasks at the first stages of the cortical processing. This is thought to be the result of a combination of mechanisms, which include feature extraction at the single cell level and geometric processing by means of cell connectivity. We present a geometric model of such connectivities in the space of detected features associated with spatiotemporal visual stimuli and show how they can be used to obtain low-level object segmentation. The main idea is to define a spectral clustering procedure with anisotropic affinities over data sets consisting of embeddings of the visual stimuli into higher-dimensional spaces. Neural plausibility of the proposed arguments will be discussed.
authors.affiliation: Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi," University of Bologna, 40136 Bologna, Italy giacomo.cocci2@unibo.it.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Cocci
authors.affiliation: Department of Mathematics, Autonomous University of Madrid, Facultad de Ciencias, 28049 Madrid, Spain davide.barbieri@uam.es.
authors.forename: Davide
authors.initials: D
authors.lastname: Barbieri
authors.affiliation: Department of Mathematics, University of Bologna, 40126 Bologna, Italy giovanna.citti@unibo.it.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Citti
authors.affiliation: Centre d'Analyse et de Mathématique Sociales, EHESS, 75244 Paris, France alessandro.sarti@ehess.fr.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Sarti
mesh_terms: D000818:Animals; D003071:Cognition / Q000502:physiology*; D006801:Humans; D009415:Nerve Net / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D013028:Space Perception / Q000502:physiology*; D013647:Task Performance and Analysis; D014793:Visual Cortex / Q000502:physiology*