The study of synesthesia has grown exponentially over the past few decades and as a result there is some level of ambiguity as to the scope of what defines it. Gail Martino and Lawrence Mark propose that synesthesia can be categorized into strong or weak. The former refers to those who experience “a vivid image in one sensory in response to stimulation in another”, whereas the latter is characterized as “cross-sensory correspondence[s] expressed through language, perceptual similarity and perceptual interactions during information processing” (Martino and Marks, 2001). This view implies that even the subtlest forms of cross-modal interactions that take place in the individual, albeit associating certain sounds to sight, deserve some credibility as being a form of synesthesia. Such a wide scope implies that far more people can experience some type of synesthesia even if its not necessarily the more exaggerated and rare forms like lexical-gustatory and grapheme color.
These rare forms of synesthesia, typically referred to as developmental, tend to persist “since birth or early childhood and remain relatively stable and systematic over time” (Brogaard 2013). However, recent evidence suggests that synesthesia is not solely developmental in the alleged “4% of the general population” (Brang and Ramachandran 2007). For the purpose of this paper I will look at studies in which serotonin appears to play a key role across not only developmental synesthesia, but also drug-induced and acquired, suggesting that there are underlying mechanisms which make synesthesia readily accessible to more people than what was once believed.
Brang and his colleague Ramachandran propose that “serotonin S2a receptors are the ‘synesthesia receptors’ in the b...
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...presence of serotonin. Nonetheless, the discovery that individuals who could not otherwise experience developmental synesthesia, can do so with increased levels of serotonin is a fairly new concept in a field that is still growing.
Works Cited
Brang, David, and Vilayanur S. Ramachandran. "Psychopharmacology of Synesthesia; the Role of Serotonin S2a Receptor Activation." National Center for Biotechnology Information. U.S. National Library of Medicine, 5 Nov. 2007. Web. 15 Dec. 2013.
Brogaard, Berit. "Serotonergic Hyperactivity as a Potential Factor in Developmental, Acquired and Drug-Induced Synesthesia." National Center for Biotechnology Information. U.S. National Library of Medicine, 21 Oct. 2013. Web. 14 Dec. 2013.
Martino, Gail, and Lawrence E. Marks. "Synesthesia: Strong and Weak." Current Directions in Psychological Science 10.2 (2001): 61-65. Print.
Schacter, D. L., Gilbert, D. T., & Wegner, D. M. (2010). Psychology. (2nd ed., p. 600). New York: Worth Pub.
In this paper, I will argue that it is more likely that the qualia of colour could be explained by physicalism rather than by property dualism. Qualia are subjective experiences, such as our senses (pg. 3). Physicalism views every property as physical, and can be explained by science (pg. 29). Property dualism refers to the philosophical view that minds are made out of one substance, but contain physical properties, and a non-physical mind (qualia) that are not related to each other (pg. 29).
In common language synesthesia is an involuntary blending of the senses by some people, which allows them to see colors when looking at numbers, for instance.
...ng pubertal period and leads to the loss of around 40% of the synaptic connections in order to improve working memory and higher linguistic ability is taken too far leaving fewer synapses in the frontal and temporal lobes (Feinberg 1983). This is usually associated with abnormality in Glutamate and Dopamine transmission. It was previously reported that substance abuse early in adolescence such as the abuse of an antidepressant can induce schizophrenia in people and many drugs were already tested on animal models such as the Amphetamine and Phencyclidine PCP (Mouri et al. 2007), hence the idea of using Bromocriptine, a psychotic drug to induce schizophrenia in mouse models and by that proving that this drug can induce schizophrenia in people especially when it is administered early during puberty where abnormal neural changes might occur due to overuse of such drugs.
In a study done by V. S. Ramachandran and Zeve Marcus, seven synaesthetes and thirteen non-synaesthetes were tested on their personal effects of the McCollough effect (2017). Collectively, this study showed that the observations made could prove the possibility that the McCollough effect can take advantage of the color connections that synesthetes already possess to strengthen the effects.
Another researcher has stated that instead of there being additional connections, the synaesthesia might be a result from disinhibited feedback in neural pat...
Rowland, L. P., ed. Merritt’s Textbook of Neurology. 7th ed. Lea and Febiger. Philadelphia: 1984.
It is clear from both animal experiments[3] and from human conditions (notably narcolepsy and multi-system degenerative
Imagine a world where numbers, letters, tastes, and sounds have color. Imagine a world where letters and numbers have personalities. For a synesthete, this is their world. Synesthesia occurs from a cross wiring in the brain. Instead of one sense being used in a particular action, multiple senses are used. Although little medical knowledge is known about the condition, it is fascinating and continues to impact our world.
N,N-dimethyltryptamine(DMT) is a psychoactive chemical in the tryptamine family, which causes intense visuals and strong psychedelic mental affects when smoked, injected, snorted, or when swallowed orally (with an MAOI such as haramaline). DMT was first synthesized in 1931, and demonstrated to be hallucinogenic in 1956. It has been shown to be present in many plant genera (Acacia, Anadenanthera, Mimosa, Piptadenia, Virola) and is a major component of several hallucinogenic snuffs (cohoba, parica, yopo). It is also present in the intoxicating beverage ayahuasca made from banisteriopsis caapi. This drink inspired much rock art and paintings drawn on the walls of native shelters in tribal Africa- what would be called 'psychedelic' art today (Bindal, 1983). The mechanism of action of DMT and related compounds is still a scientific mystery, however DMT has been identified as an endogenous psychadelic- it is a neurotransmitter found naturally in the human body and takes part in normal brain metabolism. Twenty-five years ago, Japanese scientists discovered that the brain actively transports DMT across the blood-brain barrier into its tissues. "I know of no other psychedelic drug that the brain treats with such eagerness," said one of the scientists. What intrigued me were the questions, how and why does DMT alter our percep...
"Synesthesia and Mirror Neurons." Weekends in Paradelle. 2 May 2010. Web. 24 May 2010. .
· Freedman, D.X. (1984): LSD: The bridge from human to animal. In: Jacobs, B.L. (Ed.) Hallucinogens: Neurochemical, Behavioral, and Clinical Perspectives. New York: Raven Press.
Crick and Koch introduces the argument that "to be aware of an object or event, the brain has to construct a multilevel, explicit, symbolic interpretation of part of the visual scene". Certainly the neuronal activity resulting from the varied patterns of light falling on one's photoreceptors does not alone explain the extent of visual experiences which one may conceive. Indeed the impression of completeness of any given perception proves largely false. Rather, the vivid scene has been 'made-up' by the brain, constructed out of aware...
Price, L. O., Charney, D. S., Goodman, W. K., Krystal, J. H., Woods, A. N. & Heninger, G. R. Clinical data on the role of serotonin in the mechanism of action of antidepressant drugs. Journal Clinical Psychiatry, April 1990, 51: 44-50. (cited as 5)
Because synesthesia occurs mainly in the brain, there is an interesting biology behind it. There are many theories about the biology behind why and how synesthesia affects the brain and senses. Some researchers say that synesthesia occurs because of an over abundance of neural connections in the brain, causing neurons and synapses from one sensory system to cross over into another (Rod Plotnik and Haig Kouyoumdjian 144). Researchers believe it is possible that everyone is born synesthetic, but through development the interconnected brain parts separate (“What is Synesthesia”). It has been found that women are more likely to have synesthesia than men, which indicates that synesthesia could be inherited from a trait carried on the X chromosome (“Synesthesia”).