Visual Perception Essay -- Biology Essays Research Papers

Visual Perception Any one given experience an organism perceives must incorporate several sensory systems, that involves numerous number of organs , that further more are comprised of millions upon millions of firing cells. Perception is not a direct mirroring of stimulus, but a complex chaotic patterns dependent on the simultaneously activity of neurons. This essay deals primarily with neurons from the optical sensory system. The outer ridge of the brain, known as the cerebral cortex begins the analysis of sensory messages. (1) Nevertheless, visual perception is possibly more widespread than one area of the cerebral cortex and like ly over various subcortical structures and number of different systems as well. (2) One of the many ways for the "perception process" to begin, is vision. Vision is dependent on the interaction between light input and the eye. The visual input is seen through lens that takes different light outside, refract and bend into points of light that focus on specific places on the retina. This light-sensitive tissue that lines the back of the eye consists of interconnected neurons. The three diff erent types are receptor cells, bipolar cells and ganglian cells. When photoreceptors are stimulated, they change in structure of photopigments in the receptors and transduce light input into neural activity. (2) Electrical stimulus trave ls down the axon of bipolar cells to the ganglian cells. The ganglian cells are activated through nerve impulses or action potentials and travel down the optic nerve. This activity conducts along the optic nerve to the geniculate nucleus that then travels to the mid- brain. (2) Finally the firing neurons activity travels to the cortex at the back of the brain, known as the stria... ...ic methods are more reasonable than linear, straightforward procedures. Is it reasonable that all of what one perceives is dependent exclusively on a specific set of procedures, rather than the interaction of cells, organs and systems? The former process seems to be improbable, while the latter process proves to be a chaotic, massive and cooperative. It was alluded to in class that one does not need the formulized "picture" or the visual perception. Nonetheless, I think that this added perplexity is a necessity. The visual perception of the "picture" encourages our understanding of ourselves as we ll as our surroundings. Internet Sources: http://sulcus.berkeley.edu/FLM/MS/Physio.Percept.html Ratlif f, Floyd. "Contour and Contrast," Scientific American, June 1972, pp. 91-101 Crutchfield, James. "Chaos," Scientific American, December 1986, pp. 46-57