Synesthesia is a neuronal condition in which an individual experiences stimuli in one sensory or cognitive stream leading to an experience in a second unrelated cognitive stream, commonly triggered by one of the five external senses. Further, it can tie thought patterns and emotions to concepts and ideas, such as numbers, days of the week, or months of the year. Synesthesia is classified into subtypes identified by X→Y, where X is the inducing stimulation and Y is the concurrent, resulting stimulation. Genetically invoked congenital synesthesia occurs in around 4% of the general population. The condition is thought to be an X-linked dominant trait, according to the University of Wisconsin-Madison. Research was conducted at McMaster University concerning the neural basis of the condition utilizing MRI, and it was found that both the X and Y regions of the brain light up when the X stimulant is exposed to the synesthete, which supports the Cross Activation Theory. The Cross Activation Theory is based on evidence that, across several species, sensory cortical areas are initially not as specialized as they develop to be. Instead, there are transient connections between sensory cortical areas that are pruned during childhood in an experience-dependent manner. According to the cross-activation account, synesthesia occurs when some of the connections between sensory cortical areas are not pruned. Thus, synesthetic color is evoked because connections in areas mediating the perception of sound, words, graphemes, or taste were not pruned.
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Synesthesia is a neuronal condition in which an individual experiences stimuli in one sensory or cognitive stream leading to an experience in a second unrelated cognitive stream, commonly triggered by one of the five external senses. Further, it can tie thought patterns and emotions to concepts and ideas, such as numbers, days of the week, or months of the year. Synesthesia is classified into subtypes identified by X→Y, where X is the inducing stimulation and Y is the concurrent, resulting stimulation. Genetically invoked congenital synesthesia occurs in around 4% of the general population. The condition is thought to be an X-linked dominant trait, according to the University of Wisconsin-Madison. Research was conducted at McMaster University concerning the neural basis of the condition utilizing MRI, and it was found that both the X and Y regions of the brain light up when the X stimulant is exposed to the synesthete, which supports the Cross Activation Theory. The Cross Activation Theory is based on evidence that, across several species, sensory cortical areas are initially not as specialized as they develop to be. Instead, there are transient connections between sensory cortical areas that are pruned during childhood in an experience-dependent manner. According to the cross-activation account, synesthesia occurs when some of the connections between sensory cortical areas are not pruned. Thus, synesthetic color is evoked because connections in areas mediating the perception of sound, words, graphemes, or taste were not pruned.