The Neuropsychological phenomenon of Sensory Spillovers: Synesthesia

Introduction

Have you ever tasted colors or seen sounds? Maybe you felt color, or saw flavors? This could either make a lot of sense or zero sense to some people. Whether it does or doesn’t, this phenomenon is a result of neurological functions. Dying to find out more about it? Let's explore this marvel known as Synesthesia!

What is Synesthesia?

Synesthesia is a perceptual phenomenon, meaning it affects the way the brain processes, interprets, and organizes information (Cleveland Clinic, 2023a). It is important to note that synesthesia is not a medical disorder or condition, but rather simply a symptom of normal neurological functions. 

The word synesthesia is Greek, meaning ‘to perceive together’. This is because it occurs when the brain reroutes sensory information through multiple sensory routes, rather than one alone (Banissy et al., 2014). For example, one could smell a distinct scent, and rather than routing it through the olfactory senses alone, the brain would route it through the visual pathways too. This would lead to somebody smelling AND seeing a scent simultaneously. Synesthetes (people who experience synesthesia), describe it as an out-of-body, acid trip. 

Causes and development of Synesthesia

Synesthesia is mainly a result of genetic factors. According to BetterHelp, synesthesia is often found among close relatives, which supports the claim that synesthesia is hereditary. However, in some cases, it may be developed in early childhood, and in EXCEPTIONAL cases can emerge in adulthood, as a result of special circumstances that rewire the brain (What Is Synesthesia? | Causes & Symptoms, n.d.). For example, drug exposure or brain injuries can rewire neural pathways. Moreover, neuroscientists believe that the failure of synaptic pruning during early developmental years could lead to synesthesia (Meier & Rothen, 2015). Synaptic pruning is the elimination of unnecessary neural pathways that occurs during early neurological development. Failure of this neural pruning leads to cortical hyperconnectivity, which can later be diagnosed as autism, schizophrenia, OCD, or synesthesia. 

Conclusion

To conclude, synesthesia is the marvel behind our inexplicable abilities to exhibit more than one sense at once. Synesthesia was also the magic behind the pieces of many famous artists and painters, such as Vincent Van Gogh and Wassily Kandinsky. Whether it lets you see the color of numbers or the flavor of sounds, synesthesia reminds us of the magical wonders of neuroscience!

Works cited

Cleveland Clinic. (2023a, May 3). Synesthesia. Cleveland Clinic; Cleveland Clinic. https://my.clevelandclinic.org/health/symptoms/24995-synesthesia

What Causes Synesthesia | BetterHelp. (2024). Betterhelp.com. https://www.betterhelp.com/advice/psychology/what-causes-synesthesia-understanding-cross-sensory-connections/

Banissy, M. J., Jonas, C., & Cohen Kadosh, R. (2014). Synesthesia: an introduction. Frontiers in Psychology, 5(1414). https://doi.org/10.3389/fpsyg.2014.01414

What is Synesthesia? | Causes & Symptoms. (n.d.). Exceptional Individuals. https://exceptionalindividuals.com/neurodiversity/what-is-synesthesia/

Meier, B., & Rothen, N. (2015). Developing synaesthesia: a primer. Frontiers in Human Neuroscience, 9. https://doi.org/10.3389/fnhum.2015.00211