Poort, J;
Self, MW;
van Vugt, B;
Malkki, H;
Roelfsema, PR;
(2016)
Texture Segregation Causes Early Figure Enhancement and Later Ground Suppression in Areas V1 and V4 of Visual Cortex.
Cerebral Cortex
, 26
(10)
pp. 3964-3976.
10.1093/cercor/bhw235.
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Abstract
Segregation of images into figures and background is fundamental for visual perception. Cortical neurons respond more strongly to figural image elements than to background elements, but the mechanisms of figure–ground modulation (FGM) are only partially understood. It is unclear whether FGM in early and mid-level visual cortex is caused by an enhanced response to the figure, a suppressed response to the background, or both. We studied neuronal activity in areas V1 and V4 in monkeys performing a texture segregation task. We compared texture-defined figures with homogeneous textures and found an early enhancement of the figure representation, and a later suppression of the background. Across neurons, the strength of figure enhancement was independent of the strength of background suppression. We also examined activity in the different V1 layers. Both figure enhancement and ground suppression were strongest in superficial and deep layers and weaker in layer 4. The current–source density profiles suggested that figure enhancement was caused by stronger synaptic inputs in feedback-recipient layers 1, 2, and 5 and ground suppression by weaker inputs in these layers, suggesting an important role for feedback connections from higher level areas. These results provide new insights into the mechanisms for figure–ground organization.
| Type: | Article |
|---|---|
| Title: | Texture Segregation Causes Early Figure Enhancement and Later Ground Suppression in Areas V1 and V4 of Visual Cortex |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/cercor/bhw235 |
| Publisher version: | http://dx.doi.org/10.1093/cercor/bhw235 |
| Language: | English |
| Additional information: | © The Author 2016. Published by Oxford University Press. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com |
| Keywords: | Science & Technology, Life Sciences & Biomedicine, Neurosciences, Neurosciences & Neurology, cortical layers, figure-ground segmentation, perceptual organization, vision, visual cortex, OBJECT-BASED ATTENTION, CAT STRIATE CORTEX, MACAQUE MONKEY, CORTICAL AREAS, CEREBRAL-CORTEX, FEEDBACK AXONS, NEURONS, V2, FEEDFORWARD, DYNAMICS |
| 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/1516100 |
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