Literally all you need to know about Visual Perception for your Intro Cognition class:
By Michelle Beckett-Ansa
1. Cognition isn’t just cognition.
Well, it is and it isn’t. Cognition encompasses a broad spectrum of different topics, including (but not limited to) auditory perception, embodied cognition, and our topic of the day, visual perception. Visual perception is defined as the ability to see and interpret visual information that surrounds us. We respond to things that are seen in our receptive fields, the area of the body or area surrounding the body that may trigger a stimulus.
2. Sensation vs. Perception.
Before jumping into the crazy concept that is visual perception, you absolutely need to understand the distinction between sensation and perception. To put it simply, what do your eyes see, and what does your brain understand? Sensation is the feeling that comes in contact with your body. It is the information that you receive, and must now interpret. That is where perception comes in. Perception is the interpretation of that stimulus by the parts of your body. These concepts function together to accept and interpret information gathered from your visual field.
3. Rods and Cones basically run the show.
Photoreceptors are cells that respond to light touching. The eye holds two types of photoreceptors; rods and cones. These two receptors are responsible for interpreting the signals sent through your visual field. Rods are far more numerous in the eye than cones are. They are usually located in the periphery of the retina, and are more responsive to dim light. Cones on the other hand are responsive to color visuals and direct vision. They tend to be located in the center of the retina. They are much more acute than rods, because they each have their own individual cells to attach to as opposed to rods that have one cell for multiple. Together, these two typed of photoreceptors allow you to see, and to interpret your vision.
4. People have different (mostly non-conflicting) theories about how it all works. Here’s a few.
Not people specifically, but all of psychology. To start off, there is the trichromatic theory. This states that we perceive all colors based on the combination of three colors; red, blue, and green.
Another theory, the opponent process theory of color vision, expresses the idea that cone cells are linked together to form three opposing color groupings: blue and yellow, red and green, and black and white.
Lastly, we will discuss the two-stream hypothesis. This is a theory of neural processing. The brain has two streams of information processing at one time. The ventral stream sends visual information from the visual cortex to the temporal lobe. This relays information about what it is that we saw in our receptive field. Meanwhile the dorsal stream works simultaneously to relay visual information to the parietal lobe to tell us where we are.
5. Visual Perception is crazier than you can imagine.
Here are some cool and intriguing facts relating to visual perception:
- There’s really no way to completely cover the entirety of the subject in one article, or one class.
- Almost half the brain is involved in everyday sight.
- Each eye has a blind spot. This is essentially a small hole in the center of the back of the retina where the optic nerve exits the eye. The cool part is, you don’t even notice that it’s there. Your eyes work with one another to fill in the gaps where the other cannot see.
- The muscles controlling the eyes, out of all your muscles, are the most active (during the day)
So yeah, visual perception and how It works can be pretty exciting. But then again, so is cognition! Take this info and go ace your Cognition course (at least the section on vision)!