Coen-Cagli, R;
Dayan, P;
Schwartz, O;
(2012)
Cortical Surround Interactions and Perceptual Salience via Natural Scene Statistics.
PLoS Comput Biol
, 8
(3)
, Article e1002405. 10.1371/journal.pcbi.1002405.
![[thumbnail of 1342980.pdf]](https://discovery.ucl.ac.uk/style/images/fileicons/application_pdf.png) Preview |
PDF
1342980.pdf Download (2MB) |
Abstract
Spatial context in images induces perceptual phenomena associated with salience and modulates the responses of neurons in primary visual cortex (V1). However, the computational and ecological principles underlying contextual effects are incompletely understood. We introduce a model of natural images that includes grouping and segmentation of neighboring features based on their joint statistics, and we interpret the firing rates of V1 neurons as performing optimal recognition in this model. We show that this leads to a substantial generalization of divisive normalization, a computation that is ubiquitous in many neural areas and systems. A main novelty in our model is that the influence of the context on a target stimulus is determined by their degree of statistical dependence. We optimized the parameters of the model on natural image patches, and then simulated neural and perceptual responses on stimuli used in classical experiments. The model reproduces some rich and complex response patterns observed in V1, such as the contrast dependence, orientation tuning and spatial asymmetry of surround suppression, while also allowing for surround facilitation under conditions of weak stimulation. It also mimics the perceptual salience produced by simple displays, and leads to readily testable predictions. Our results provide a principled account of orientation-based contextual modulation in early vision and its sensitivity to the homogeneity and spatial arrangement of inputs, and lends statistical support to the theory that V1 computes visual salience.
| Type: | Article |
|---|---|
| Title: | Cortical Surround Interactions and Perceptual Salience via Natural Scene Statistics. |
| Location: | United States |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1371/journal.pcbi.1002405 |
| Publisher version: | http://dx.doi.org/10.1371/journal.pcbi.1002405 |
| Language: | English |
| Additional information: | © 2012 Coen-Cagli et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This work was funded by the NIH grant CRCNS-EY021371, and the Alfred P. Sloan Foundation (OS); and the Cognitive Systems Foresight Project, grant BB/E000444/1 and the Gatsby Charitable Foundation (PD). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. |
| Keywords: | Animals, Computer Simulation, Humans, Models, Neurological, Models, Statistical, Nerve Net, Orientation, Space Perception, Visual Cortex |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1342980 |
Loading...
Loading...Loading...Loading...Archive Staff Only
 |
View Item |
