How visual images are captured and encoded by the retina and represented in the primary visual cortex

Type :

Term papers

Pages :

8 pages

Format :

.doc

Published date :

05/04/2009

Category :

Science & technology

Sub category :

Medical studies

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Summary :

Introduction
The retina as a whole
1. How it works
2. The cells of the retina
3. Photoreceptors
4. The relative concentrations of rods and cones
5. The photo pigments
The bipolar cell
1. Types of bipolar cells
2. The bipolar cell organization
3. The link between bipolar and ganglion cells
4. Types of ganglion cell
The LGN
1. The visual receptive fields of the LGN cells
2. The major input into the LGN
The receptive fields in the retina
The neurones of the magnocellular pathway
Conclusion
Bibliography

Abstract

visual perception is the ability to interpret information from visual light reaching the eye, the resulting perception of this information is sight. Light is electromagnetic energy that is emitted in the form of waves, it is reflected off an object to enter the eye, and is refracted by the eye to be focused upon the retina at the back of the eye. The retina contains photo receptors that convert the light energy into neural activity. The retinal neuron axons form bundles, called the optic nerve, which passes through the orbit of the skull to enter the base of the brain near the pituitary. The retina as a whole is specialized to detect differences in the intensity of light falling on different parts of it, thus determining the aspects of shape and size of an object. Light is focused on the retina, to recreate the image that the light being collected has been reflected from, by the refractive action of the lens and cornea, such that light striking the curved surface of the cornea bends to converge on the back of the eye, and light entering the center of the eye passes straight to the retina, resulting in an inverted representation of the image the light is reflected from.