Course Text:

Goldstein, E. B. (2017). Sensation and Perception. 10th edition. California: Cengage.

Original Question:

By now you've probably noticed in your assigned readings that the study of sensation and perception focuses on things you may have experienced but never given any thought to--for example, the "Purkinje shift". We don't think much about these phenomena because our world is full of them, and if we had to be conscious of every sensation and its accompanying perception that we ever experienced our brains would have little time for anything else (!) but research scientists have studied them in detail.

This leaves us with the question--do these interesting and sometimes odd things matter? The answer is yes, but why and how varies depending on the particular phenomenon. Because there are real-life phenomena associated with everything discussed in our readings and dialoguing about them can bring theory and fact to life, for the remainder of our forum assignments we will be doing the following:

In the initial forum post, please describe how one of the phenomena mentioned in the readings explains an everyday event that you have experienced or observed and then suggest how this phenomenon might have serious consequences (so first its everyday occurrence and impact and then ways in which it can have serious impact).

For the purpose of this assignment, we will define "serious impact" as something that has negative consequences to health and safety of the self or others rather than something that is inconvenient or embarrassing. Not being able to distinguish colors under certain light may lead to getting home after a shopping trip only to find out an outfit isn't the color you thought it was, which can be inconvenient and/or embarrassing. Not being able to distinguish colors under certain war zone conditions can be safety and life threatening.

Please be specific, thorough and concrete. Adding onto the end of a post a statement or two that something could be a problem is not sufficient. Additionally, saying you don't know of any negative consequences isn't permitted. Doing so will void your forum assignment points.

You will need to explain how the phenomenon specifically has a negative impact. An example, described in Nicholas Wade's 2000 "The Natural History of Vision" is below (NOTE: Because this one has already been applied, you must select another). Unless discussing one of the more common disorders, like a lack of depth perception or hearing loss, please avoid "I think I have this" syndrome. This is something that medical students often fall prey to in the early years of medical school because they spend so much time studying human disorders, from the very common to the exceedingly rare.

Reply to the following response with 200 words minimum. (please make response as if having a conversation, respond directly to some of the statements in below post.)

For this week's discussion I have selected to discuss the phenomenon:

"Monochromatism," which is an extremely rare form of colorblindness that affects around 10 people out of a million. This condition is typically hereditary. The medical definition of monochromatism, as defined by Medicine Net, is the total inability to perceive color; "A person with true monochromatism perceives only black, white, and shades of gray" (2013).

We have learned the basics of the human eye (cornea and lens, retina, optic nerve) and how we filter light through the pupil which is surrounded by the iris. The light is then reflected on the back of the eye by the lense. Covering the back of the eye are tiny photoreceptors. Two types of photoreceptors that we have to help collect the visual data of the environment are called "cones" and "rods" (shaped as such in the eye).

The cones and rods of the eye have different functions, meaning they see different things. Rods are good for seeing in the dark and things that move, but are in black and white and not very detailed. Cones are good for seeing in the light and still objects. Cones are good for detail and color (Dr. Blaikie, n.d.). Rods and cones play an important role in our vision.

There are different types of color blindness, such as red-green color blindness (which is the most common) or blue-yellow color blindness. Red-green color blindness is from losing or having "limited function of red cone (known as protan) or green cone (deutran) photopigments " and with blue-yellow colorblindness, "blue-cone (tritan) photopigments are either missing or have limited function" (National Eye Institute, 2015). Monochromacy, on the other hand, is complete color blindness. There are two types of monochromacy: cone monochromacy and rod monochromacy (or achromatopsia).

Cone monochromacy is a result of failure of two of the three cone cell photopigments. This failure causes difficulty in distinguishing colors, because the brain compares signals from the different types of cones in order to see color. However, with rod monochromacy none of the cone cells have functional photopigments. This type of monochromacy is present when born, it is rare, and the most severe form of colorblindness. "Rod monochromacy is thought to only occur in around 0.003% of people or less (Total Color Blindness, 2015). It is important to note that because of the way the rods in the eye respond to light, people with rod monochromacy may have difficulty in brightly lit environments (photophobia).

Unfortunately there is no cure for colorblindness and functioning in daily life may pose some challenges. Monochromacy may go undetected in babies in small children. Children growing up in school may have a difficult time understanding colors as they learn. Some children might try to hide the fact that they are unable to see color; they don't want to appear abnormal. Also many learning materials are color coordinated. Children might find food that is colorless to them less appetizing, which could affect a healthy diet. As an adult, it could be difficult to navigate through traffic, read and follow maps, find or wear matching clothes, distinguish if a fruit/vegetable is ripe, or if a meat is cooked to a certain color. Total color blindness is not life threatening, but does require a sort of life adjustment. "Many children with rod monochromatism need early and specialist care from the local visual impairment support team" (Dr. Blaikie, n.d.).

Resources

Blaikie , A., Dr. (n.d.). Medical Information on Rod Monochromatism.

Total Color Blindness. (2015, April 13).

Medicine Net. (2013, August 28). Medical Definition of Monochromatism.

The National Eye Institute (NEI). (2015, February 01). Facts About Color Blindness.