Understanding Synesthesia
We grow up learning about the five senses-- sight, smell, sound, taste, and touch. We grow up learning about the body parts associated with these senses-- eyes, nose, ears, tongue, and skin, respectively. These associations are ingrained into us, but it is not always the case. Synesthesia, the neurological phenomenon in which the stimulation of a sensory or cognitive pathway results in automatic experiences in another sensory or cognitive pathway, is found roughly in one to twenty five percent of the population. While this appears to be a rather broad range, this uncertainty is generated by the challenges in diagnosing synesthesia, as will be discussed below. It is important to note that synesthesia is not a disease or disorder, but rather a phenomenon that occurs.
For those who do not have synesthesia, the concept may be rather overwhelming or inconceivable. The idea of being able to perceive letters and numbers in different colors, to hear colors, or to touch smells seems perhaps impossible, simply because their perception of the world is different. But for those with synesthesia, this is their perception of the world. By extension, most people with synesthesia are not aware that they do have synesthesia, as they believe that others have the same experiences they do, or are afraid to stand out and therefore not mention it.
The most common type of synesthesia is grapheme color synesthesia, in which numbers and letters are perceived as different colors. Another important point is that there is no universal association of a number and letter to a color among synesthetes-- they each have different pairings. Although there is variety among individuals, there is consistency within an individual, so the same color is always paired with the same number (i.e. blue is always paired with 6); these associations do not change over time. However, the number ‘6’ and the word ‘six’ may be perceived differently, if the three letters ‘s’, ‘i’, and ‘x’ are associated with different colors from each other, and from the number ‘6’.
An advantage to having grapheme color synesthesia is when solving a word-search puzzle or crossword puzzle-- instead of picking out letters and words, a synesthete can look for certain colors for help. Looking for a specific word or phrase in a lengthy list or article can also be facilitated with grapheme color synesthesia, as well as when it comes to memorization. While a disadvantage may be the overlap in associations-- blue, for example, pairs with the number ‘6’ as well as the letter ‘A’-- many synesthetes do not view this condition as a bother to their daily lives. Of course, as mentioned before, many are not aware that they have synesthesia and would therefore not view it as a disadvantage at all.
When it comes to diagnosing synesthesia, there are many online quizzes that are available. While the results should all be taken with a grain of salt, tests are the only way to determine synesthesia. A color congruency or consistency test will ask individuals to pair colors and graphemes, and then repeat after a certain period of time. Results may be skewed if individuals without grapheme color synesthesia develop memorized color associations, with or without the intention of doing so. In order to obtain positive results, some may purposely memorize their answers and provide the same pairings when asked again. Others may have unintentionally developed color associations (i.e. the color of a sports jersey is blue and the number of it is 6), and this would also affect the results of these tests.
To avoid and filter out these easily made factors, a Stroop test can be applied. Continuing with the example of blue and the number ‘6’ being paired, the number ‘6’ can be displayed in two colors, blue or red. The participant will have to decide if the number ‘6’ is shown in the color that the association is made with (blue) or not (red). The time that it takes to make the decision is what matters in determining if one has grapheme color synesthesia or not, as well as the accuracy of the answers. Those with a longer reaction time are less likely to have synesthesia, as these questions will be intuitive for synesthetes. Even though a Stroop test limits the potentially skewed results due to memorization of color associations, these are done online and so technical limitations of the Internet would apply, such as the speed it takes for the answer to be submitted.
Furthermore, online testing is only applicable to certain types of synesthesia. Since grapheme color synesthesia is the most common form, it makes sense that most of the tests are for grapheme color synesthesia. Other forms of synesthesia are impossible to test online, such as the association of a smell with color, or of taste with color. In addition, those who are not aware of having synesthesia tend to score lower on these tests than those aware of their synesthesia, which would be another means of skewing test results. All of these play into the rather broad and uncertain estimate of the prevalence of synesthesia.
As mentioned, there are many limitations to diagnosing synesthesia, especially due to the many forms that it has and the variety of factors in testing. Regardless, this does not undermine the condition of synesthesia and how it affects the perception one may have of the world around them. Synesthesia is a well-researched and still developing field in modern day science, as there is still much to be known and studied, shown by the many challenges and limitations that arise from testing and diagnosing.
References:
https://www.apa.org/monitor/mar01/synesthesia
https://www.nytimes.com/2011/11/22/science/mapping-grapheme-color-synesthesia-in-the-brain.html