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| Content Provider | World Health Organization (WHO)-Global Index Medicus |
|---|---|
| Author | Jin, Jianzhong Kremkow, Jens Wang, Yushi Lashgari, Reza Komban, Stanley J. Jansen, Michael Li, Xiaobing Alonso, Jose-manuel Zaidi, Qasim |
| Description | Author Affiliation: Kremkow J ( Graduate Center for Vision Research, Department of Biological and Visual Sciences, State University of New York College of Optometry, New York, NY 10036.); |
| Abstract | Astronomers and physicists noticed centuries ago that visual spatial resolution is higher for dark than light stimuli, but the neuronal mechanisms for this perceptual asymmetry remain unknown. Here we demonstrate that the asymmetry is caused by a neuronal nonlinearity in the early visual pathway. We show that neurons driven by darks (OFF neurons) increase their responses roughly linearly with luminance decrements, independent of the background luminance. However, neurons driven by lights (ON neurons) saturate their responses with small increases in luminance and need bright backgrounds to approach the linearity of OFF neurons. We show that, as a consequence of this difference in linearity, receptive fields are larger in ON than OFF thalamic neurons, and cortical neurons are more strongly driven by darks than lights at low spatial frequencies. This ON/OFF asymmetry in linearity could be demonstrated in the visual cortex of cats, monkeys, and humans and in the cat visual thalamus. Furthermore, in the cat visual thalamus, we show that the neuronal nonlinearity is present at the ON receptive field center of ON-center neurons and ON receptive field surround of OFF-center neurons, suggesting an origin at the level of the photoreceptor. These results demonstrate a fundamental difference in visual processing between ON and OFF channels and reveal a competitive advantage for OFF neurons over ON neurons at low spatial frequencies, which could be important during cortical development when retinal images are blurred by immature optics in infant eyes. |
| ISSN | 00278424 |
| e-ISSN | 10916490 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Issue Number | 8 |
| Volume Number | 111 |
| Language | English |
| Publisher | National Academy of Sciences |
| Publisher Date | 2014-02-01 |
| Publisher Place | United States |
| Access Restriction | Open |
| Subject Keyword | Dark Adaptation Physiology Models, Neurological Photoreceptor Cells, Vertebrate Thalamus Visual Cortex Visual Pathways Visual Perception Animals Evoked Potentials, Visual Photic Stimulation Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Multidisciplinary |
| Content Type | Text |
| Resource Type | Article |
| Subject | Multidisciplinary |
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