You are here : Home > The Institute > News > From V1SH to CPD: feedforward, feedback, and the attentional bottleneck in vision

Conference | Brain


NeuroSpin Conferences

From V1SH to CPD: feedforward, feedback, and the attentional bottleneck in vision

From 6/28/2021 to 6/28/2021
webinar

Li ZHAOPING (Tübingen MPI, Germany) will give a talk on Zoom on June 28th.

www.lizhaoping.org


(1) Zhaoping, L. (2019) A new framework for understanding vision from the perspective of the primary visual cortex Current Opinion in Neurobiology, volume 58, page 1-10.
(2)  Zhaoping, L. (2020) The flip tilt illusion: visible in peripheral vision as predicted by the Central-Peripheral Dichotomy (CPD). i-Perception, 11(4), 1--5.
(3)  Zhaoping, L. (2021) Contrast-reversed binocular dot-pairs in random-dot stereograms for depth perception in central visual field: Probing the dynamics of feedforward-feedback processes in visual inference, Vision Research, vol. 186, pages 124-139.

Short abstract:

V1SH is the V1 Saliency Hypothesis, and CPD is the Central-Peripheral Dichotomy.
I will explain how they motivate a new framework: Visual attention selects only a tiny fraction of visual input information for further processing.  Selection starts in the primary visual cortex (V1),  which creates a bottom-up saliency map (V1SH) to guide the fovea to selected visual locations via gaze shifts.
This motivates a new framework that  views vision as consisting of encoding, selection, and decoding stages, placing selection on center stage.  It suggests a massive loss of non-selected information from V1 downstream along the visual pathway.  Hence, feedback from downstream visual cortical areas to V1 for better decoding (recognition), through analysis-by- synthesis, should query for additional information  and be mainly directed at the foveal region (CPD).  Accordingly, non-foveal vision is not only poorer in spatial resolution, but also more susceptible to many illusions.  I will show  some illusions arising from V1's feedforward inputs limited by the attentional bottleneck, and use random-dot stereograms to illustrate how top-down feedback constructively utilizes the feedforward inputs in some visual inferences and vetoes feedforward inputs in other cases, depending on the nature of the feedforward inputs

Practical information


replay




Top page