The psychology of information processing, that is, the reasoning behind how the individual interacts with the environment, is mediated by two cognitive processes: sensation and perception. Perception should be understood as the process of holistic reflection of an object and its recording in the individual’s consciousness, initiated by a physical stimulus to the senses. Perception is realized by processing incoming information in the brain, so this process is profound and complex. Unlike perception, sensation reflects only partial information about an object, so it does not allow a holistic picture. With sensation, individuals cognize the world in a nonwhole way: the eyes allow them to see the color and shape of objects, and the ears detect sound waves. Both cognitive processes involve stimulation of the senses, and it is correct to point out that perception is a broader concept than sensation: perception without sensation is impossible.
An excellent strategy for gaining a deeper understanding of sensation and perception and how they work together is to use an example. In particular, it is possible to trace the entire way in which information about an object reaches the individual’s brain, where processing takes place through the eyes. According to CrashCourse (2014), the eyes are one of the essential sense organs through which an individual consumes a great deal of information. People can indeed live without visual receptors, but such an existence is associated with many problems and limitations. Usually, however, the path of visual information begins with object recognition: this requires enough light for the eye to discern and discern the shape, size, and color of the object in front of it.
The light signal first hits the pupil, which as an iris, is responsible for how much light should enter the eyeball. In low light conditions, more light is required for processing, and thus the pupil expands; alternatively, in high light conditions, there is no need for so much light in the eye, so the pupil visibly narrows. The light signal that has passed through the iris reaches the lens, which acts as an optical lens. Light rays are collected on the lens of the eye, then refracted to come into focus together. In people with vision problems, the focal distance is different than usual because the eye becomes either elongated or, conversely, too constricted (Griff, 2021). Interestingly, after the rays are collected in focus, the imaginary image of the object is reversed so that later information about the perceived object is reversed. In either case, the light collected in the beam reaches the optic nerve on the posterior surface of the eyeball, from where the information is converted into an electrical impulse.
At this stage, the process of sensation is complete. Before the impulse reaches the brain structures, the individual does not yet understand what he sees in front of him. However, because of the relatively fast recognition mechanism, people hardly notice the delay between sensation and perception. The nerve impulse moving along the optic nerve reaches the visual cortex in the occipital lobe of the large hemispheres of the brain. It is in this center that the perceptual process takes place, in which the brain, which has received the signal about the inverted object, not only returns it to the correct angle but also recognizes all the information that has arrived.
It is true that visual information about objects is not only associated with shape and boundary recognition. In fact, through the eyes, the brain perceives the color of the object it is looking at: an apple is perceived as red, a traffic light as green, and the sky as blue. Perception of color is due to the presence of cone receptors, which recognize red, green, and blue pigments; the integration of different receptors is able to cover the variety of colors available. For black and white perceptions are responsible for the rods photoreceptors, which, like the cones, are located on the retina.
References
CrashCourse. (2014). Homunculus: Crash course psychology #6 [Video]. YouTube. Web.
Griff, A. M. (2021). Nearsighted vs. farsighted: How to tell the difference. Healthline. Web.