| Synesthesia | |
|---|---|
| Other names | Synaesthesia[1] |
 | |
| Some of those affected perceive certain letters and numbers as also colors. | |
| Specialty | Psychiatry, neurology |
| Symptoms | Experiencing one sensation as an additional sensation[1] |
| Types | At least 61[2] |
| Causes | Unclear[3] |
| Risk factors | Family history, sensory loss, LSD[1] |
| Differential diagnosis | Illusion, hallucination[1] |
| Frequency | ~4% of people[4] |
Synesthesia is a phenomenon in which stimulation of one sensory or cognitive pathway also leads to involuntary experiences in another sensory or cognitive pathway.[1][4] The most common stimulations are letters, numbers, or words; and the most common experiences are colors or textures.[1] Other types may involve days, music, taste, or people.[1] People may have more than one type.[1]
The cause is unclear.[3] Cases may develop earlier in life or be acquired following a precipitating event.[1] Risk factors include family history, sensory loss such as blindness, and substances like lysergic acid diethylamide (LSD).[1] About 40% of cases have a first-degree relative who is affected.[4] The underlying mechanism may involve decreased neuronal inhibition or decreased pruning of nerve connections.[5] There remains ongoing discussion on to how best define the condition.[1][2]
Between 2% and 20% of people are affected to some degree.[1] Males and females appear to be affected with similar frequency.[1] The condition may result in benefits in cognitive processing such as creative ability.[4] Some have used it to help with memorization.[4]
The earliest recorded case may be from 1690 by philosopher John Locke, who described a blind man who experienced the color scarlet when he heard the sound of a trumpet.[6] However, some dispute if what Locke described was an actual instance of the condition or a metaphor.[7] The first medical account is attributed to German physician Georg Tobias Ludwig Sachs in 1812.[7][8][9] The term is from the Ancient Greek σύν syn, meaning "together", and αἴσθησις aisthēsis, meaning "sensation".[10] Those who have a long term history of such experiences are known as synesthetes.[11]
References edit
- ^ a b c d e f g h i j k l m Ward, J (2013). "Synesthesia". Annual review of psychology. 64: 49–75. doi:10.1146/annurev-psych-113011-143840. PMID 22747246.
- ^ a b Simner J (February 2012). "Defining synaesthesia" (PDF). British Journal of Psychology (Review). 103 (1): 1–15. doi:10.1348/000712610X528305. PMID 22229768. Archived (PDF) from the original on 9 July 2019. Retrieved 17 July 2022.
- ^ a b Kelly, Evelyn B. (23 November 2015). The 101 Most Unusual Diseases and Disorders. ABC-CLIO. p. 269. ISBN 978-1-61069-676-0. Archived from the original on 5 August 2022. Retrieved 25 July 2022.
- ^ a b c d e Brang, D; Ramachandran, VS (November 2011). "Survival of the synesthesia gene: why do people hear colors and taste words?". PLoS biology. 9 (11): e1001205. doi:10.1371/journal.pbio.1001205. PMID 22131906.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ Cavallaro, Dani (2 October 2013). Synesthesia and the Arts. McFarland. p. 22. ISBN 978-0-7864-7563-6. Archived from the original on 5 August 2022. Retrieved 25 July 2022.
- ^ Cavallaro, Dani (2 October 2013). Synesthesia and the Arts. McFarland. p. 53. ISBN 978-0-7864-7563-6. Archived from the original on 5 August 2022. Retrieved 25 July 2022.
- ^ a b Jewanski J, Day SA, Ward J (July 2009). "A colorful albino: the first documented case of synaesthesia, by Georg Tobias Ludwig Sachs in 1812". Journal of the History of the Neurosciences. 18 (3): 293–303. doi:10.1080/09647040802431946. PMID 20183209. S2CID 8641750.
- ^ Herman LM (2018-12-28). "Synesthesia". Encyclopaedia Britannica. Archived from the original on 29 July 2019. Retrieved 2019-01-25.
- ^ Konnikova M (2013-02-26). "From the words of an albino, a brilliant blend of color". Scientific American Blog Network. Archived from the original on 2016-09-20. Retrieved 2019-01-25.
- ^ Robertson, Lynn C.; Robertson, Lynn C.; Sagiv, Noam; Sagiv, Research Fellow Noam (2005). Synesthesia: Perspectives from Cognitive Neuroscience. Oxford University Press, USA. p. 3. ISBN 978-0-19-516623-1. Archived from the original on 2022-08-05. Retrieved 2022-07-25.
- ^ van Campen C (2009). "The Hidden Sense: On Becoming Aware of Synesthesia" (PDF). Teccogs. 1: 1–13. Archived from the original (PDF) on 8 July 2009.