Motion coding in the rodent retina under stimulation with complex images.
Motion detection is one of the key tasks of the visual systems and has motivated a large body of research. However, the experimental oversimplification has prevented the extrapolation of results to naturalistic and complex situations. On the other hand, it has been proposed that the visual system is...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2018 |
| País: | Chile |
| OAI Identifier: | oai:repositorio.anid.cl:10533/232825 |
| Acceso en línea: | https://hdl.handle.net/10533/232825 |
| Access Level: | acceso abierto |
| Palabra clave: | Ciencias Naturales Otras Ciencias Naturales |
| Sumario: | Motion detection is one of the key tasks of the visual systems and has motivated a large body of research. However, the experimental oversimplification has prevented the extrapolation of results to naturalistic and complex situations. On the other hand, it has been proposed that the visual system is tuned to the statistical characteristics of the images that the animal can find in its natural environment. Evidence of this tuning has been reported in different areas of the visual cortex, while in the retina, has only been reported for relatively simple aspects such as the intensity and wavelength distribution of light. To study the effect of the statistical properties of natural images on the motion response on the retina of a diurnal rodent (Octodon degus), we had used synthetic complex textures in which we modulated the degree of complexity in terms of the variability of signals (e.g. spatial frequency) contained in the stimulus, and analyzing the response at the individual and population level. The results, from a total of 308 cells from two different animals, show that, even though that at the population level complex stimuli generate lower responses (up to 60% compared to simple stimuli), it is still possible to reliably extract the relevant information, such as: position or speed of moving objects. This means that under these conditions coding tends to be more efficient, an equivalent decoding performance is achieved with fewer spikes, and thus with less energy expenditure. Additionally, when comparing the responses elicited by the simple and complex stimuli, it is observed that for the complex stimuli, 40% of cells responds to a narrower range of spatiotemporal parameters, but do it with a higher response, i.e. they have a narrower spatiotemporal tuning, a phenomenon that can also be seen in different areas of the visual cortex when stimulated with complex images. The later suggest that adaptation to the statistics of natural scenes appears at the earliest stages of the visual system: The retina. |
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