April 19, 1994 - April 19, 2027

  • Date:25ThursdayOctober 2018

    Hierarchical dynamics of visual inference

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    Time
    12:30
    Location
    Nella and Leon Benoziyo Building for Brain Research
    Lecturer
    Prof. Jochen Braun
    Institute of Biology Otto-von-Guericke Unversity, Magdeburg
    Organizer
    Department of Brain Sciences
    Contact
    DetailsShow full text description of Benoziyo Brain Research Building Room 113 Host: Prof. Dov...»
    Benoziyo Brain Research Building Room 113

    Host: Prof. Dov Sagi dov.sagi@weizmann.ac.il tel: 3747
    For assistance with accessibility issues, please contact naomi.moses@weizmann.ac.il
    AbstractShow full text abstract about Visual input is noisy, variable, and ambiguous. Optimal inf...»
    Visual input is noisy, variable, and ambiguous. Optimal inference of physical causes is challenging even for a restricted set of causes (e.g., orientations and spatial frequencies). It is well understood (e.g., Veliz-Cuba et al., 2016) that stochastic dynamical systems can approximate optimal inference by continuously accumulating and evaluating visual evidence. I will argue that the dynamics of multi-stable perception is consistent with just such an inference mechanism. Its psychophysically observable characteristics fully constrain a hierarchical dynamics with three levels, the lowest of which may conceivably correspond to cortical columns or clusters of columns. Given suitable inputs, this hierarchical dynamics accumulates and evaluates noisy evidence to make nearly optimal categorical discriminations. Moreover, its dynamical features seem to afford functional benefits in a volatile world, such as balancing stability and sensitivity of inference.

    References:
    Cao, Pastukhov, Mattia, Braun (2016) Collective activity of many bistable assemblies reproduces characteristic dynamics of multistable perception. J. Neurosci., 36: 6957-72.

    Veliz-Cuba, Kilpatrick, Josic (2016) Stochastic models of evidence accumulation in changing environments. SIAM Review, 58: 264-289.

    Lecture