Sensation and perception are two terms that are related, but that each one has a different meaning. Sensation refers to the feeling we experience in response to information received through our sense organs. Sensation is also the basic immediate experiences generated by single isolated stimuli. On the other hand, perception is the way our body is organized to interpret those feelings; recognition of objects that comes from combining the sensations with the memory of previous sensory experiences.
In other words, perception can be understood as the appropriation or capture of the surroundings, and sensations are the tools, by which you may perceive that environment. Summarizing, we can say that while sensation involucres feelings, perception involucres ideas. Let’s look an example to see the difference between them. When a musician plays a note on the piano, its tone and volume characteristics are sensations. If you hear the first four notes and you recognized as part of a symphony, one can say that perception is experienced.
The differences between sensation and perception are not clear, but it is considered that in some cases one pass just after the other. It is said that the feeling usually comes before the perception and that functional difference is a simple and easy; in the sensitive process a stimulus is perceived as a door alarm, then analyzed and compared (perception), the information this stimulus gives is resolved with an attitude of alert to any danger or simply a matter of turning off the button accidentally activated the alarm.
All of this is the accumulation of great information that is interrelated to reach a conclusion. Related to the vision world there are many terms that we should take into account. Some of them are Rods/Cones, Trichromatic and Opponent-Process Theories of Color Vision, Afterimages. Rods and Cones are retinal cells that contain chemicals that respond to light. When light strikes these chemicals, they break apart, creating a signal that can be transferred to the brain.
While rods respond in dim light, cones are involved in color vision. There are two main theories that explain how the vision world works. The Trichromatic theory states that by mixing pure versions of blue, red and green light in different ratios, they could produce any other ratios. The Opponent- Process theory suggested that color sensitive visual elements in the eye are arranged into three kinds of pairs and that the members of each pair oppose, or inhibit each other.
Each elements signals one color or the other (red or green, blue or yellow, black or white), but never both. The last concept, afterimage is an optical illusion that refers to an image continuing to appear in one’s vision after the exposure to the original image has ceased. Together, the Trichromatic and opponent process theories explain most of what we now know about the complex process of color vision. We see colors because our three types of cones have different sensitivities to different wavelength of light.
But it is more complex than all this. The cones are connected to ganglion cells that contain pair of opposing elements that respond to different colors and inhibit each other. This explains the basis for afterimages. Therefore, the Trichromatic theory explains color vision as it relates to rods and cones, whereas the opponent-process theory explains color vision as it relates to the ganglions cells (helps to explain afterimages)..