“Why is the sky blue?” The question that children love to ask. Frankly, I want to know the answer too. Before tackling this question, we need to answer the question, “What color is the sky?” To me, the sky’s the limit (pun intended). Today on this beautiful and sunny day, the sky is blue, but when it is cloudy and gloomy, the sky is grey. At night the sky is black with the presence of stars that are spread throughout the galaxy. The sky can present itself as a spectrum of colors. During sunrise it is a refreshing mixture of yellow, orange, and blue. During sunset, the sky is a gorgeous blend of the rainbow from royal purples to warm, sultry reds. The colors of the sky can vary depending on your location on Earth. For example, during the northern lights, it is an array or colors that light up the sky. There are numerous answers to what the color of the sky actually is, but these are just examples of how I see the sky.
However, the perception of color is really at the core of this question. When we think about how we perceive the color of the sky, the answer to this simple question becomes quite complicated. There are many different ways that people see different ranges of color. This is quite special because these experiences and qualities allow for us to experience the world quite differently. People with “normal vision” will perceive the sky differently than others with something such as synesthesia.
Based on my thought process to answer this question, I really dove into different ways people with synesthesia are different in terms of how they perceive the world. Synesthesia is a phenomenon in which people experience unusual percepts elicited by the activation of a sensory modality that is unrelated or a cognitive process (Safran and Sanda, 2014). It is truly fascinating that people experience the world in such a distinct and unique way.
The literature provides great resources to better understand how people with synesthesia process many different stimuli in the world. In a study by Itoh et al. (2019), the experimenters performed a Stroop-like test in individual with synesthesia. The Stroop test is a neuropsychological test to test the ability to inhibit cognitive interference that happens when the processing of a specific feature of a stimulus disrupts the simultaneous processing of a different stimulus (Scarpina and Tagini, 2017). For example, one must say the color of a word and not the actual word itself. When the color of the word and the word itself differ, this task seems to become increasingly difficult. The authors did this with people with synesthesia, except with an auditory stimulus because some people with synesthesia relate a color and sound together. This was done to test the automaticity of pitch class with relation to color. They did this by presenting pitch class names (e.g., do, re, and mi) in font colors that lined up with their color sensations. These results showed that people with synesthesia had decreased time in identifying font color when the color was incongruent with their associated pitch class names, concluding that pitch-class synesthesia is a genuine type of synesthesia (Itoh et al., 2019).
Synesthetes have been implicated to have a cross activation of visual areas that processes shape and color, supporting how visual stimuli lead to their unique perceptions of the world (Amsel et al., 2017). A review by Safran and Sanda (2014) took a look into how people with color synesthesia have varying associations in regards to perceptions, emotions, and consciousness. For example, synesthetes showed improved digit identification because each number is represented by a color, making a specific digit stand out. Some synesthetes experience their emotions and understanding through color, as shown in the review. An example that was shown was how a painting called “Vision” showed how the synesthetic painter drew out the visual experience of a needle puncture during an acupuncture session (Safran and Sanda, 2014).
To me, I would interpret it as a red splotch that could be blood. Clearly, my interpretation is far less poetic and meaningful when compared to the synesthete’s perception. Even within this review, the authors explored and reviewed many different ways that people with synesthesia navigate the world around them.
It is genuinely mind-blowing how the person on my right can interpret the world completely differently than the person on my left. I never would have imagined how a simple question like, “What color is the sky,” could be such an intriguing conversation starter.
Amsel, B. D., Kutas, M., & Coulson, S. (2017). Projectors, associators, visual imagery, and the time course of visual processing in grapheme-color synesthesia. Cognitive Neuroscience, 8(4), 206–223. https://doi.org/10.1080/17588928.2017.1353492
Itoh, K., Sakata, H., Igarashi, H., & Nakada, T. (2019). Automaticity of pitch class-color synesthesia as revealed by a Stroop-like effect. Consciousness and Cognition, 71, 86–91. https://doi.org/10.1016/j.concog.2019.04.001
Safran, A. B., & Sanda, N. (2015). Color synesthesia. Insight into perception, emotion, and consciousness: Current Opinion in Neurology, 28(1), 36–44. https://doi.org/10.1097/WCO.0000000000000169
Scarpina, F., & Tagini, S. (2017). The Stroop Color and Word Test. Frontiers in Psychology, 8. https://doi.org/10.3389/fpsyg.2017.00557