Context and Significance: Overview: Synesthesia is an intriguing neurological condition that is relatively rare and not well studied. It comes in many different forms, but the common denominator in all variations is “the automatic activation of unusual simultaneous experiences in response to ordinary inducing stimuli.” In other words, stimulation of one sensory system causes a response in a different, unrelated sensory system. Investigation of this phenomenon may allow for a more in-depth view of the various sensory systems and their integration. Understanding synesthesia is important to learn more about the underlying brain structures and the development of our senses. Grapheme-color synesthesia is the most common form of synesthesia in which people display consistent colors associated with letters and numbers. As with all forms of synesthesia, the cause is unknown. A study by Simner et. al suggests that synesthetes (individuals with synesthesia) develop these associations during childhood as they learn the alphabet and number sequences. Furthermore, a study by Jäncke et. al suggests that synesthesia may be caused by greater structural connectivity and more cortical matter in the fusiform gyrus and areas of the V4 complex. A study by Rouw et. They also all found greater presence of white matter in the inferior temporal cortex for synesthetes and greater hyperconnectivity for those who could project color into the outside world compared to those who could only visualize colors in their mind. This distinction infers that synesthesia is likely caused by abnormalities in brain development, and research conducted by Simner et. al suggests that a basic level of cognition is required before these associations can form. It is largely unknown whether this difference in brain matter is caused genetically or in some other way. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Main hypothesis: I hypothesize that grapheme-color synesthesia is the result of an abnormal genetic accumulation of neural connections in the inferior temporal cortex and areas near the V4 complex. I will test this by monitoring brain activity during stimulation using MRI and EEG in regions associated with visual signals, color processing and perception (V4 complex, fusiform gyrus, inferior temp. cortex) and attempt to perform anisotropy measurements fractional in these regions to determine the volume and composition of the neural connection. To determine whether grapheme-color synesthesia has a genetic basis, these tests will be performed with blood relatives of the affected person who give consent. Rationale: These experiments will be performed under the assumption that the areas responsible for letter/number perception and color processing interact in individuals with grapheme-color synesthesia. The use of MRI procedures can determine whether there is an intensification of brain activity through changes in blood flow when a synesthete perceives letters/numbers compared to when an unaffected individual does the same. This will narrow down the affected areas in the brain and perhaps even target new ones. For the same purpose, invasive EEG monitoring will also be used by measuring currents that indicate the activity of neurons in these regions when stimulated. Furthermore, a statistically significant increase in cortical matter should influence the EEG reading if hyperconnectivity is indeed responsible for synesthesia. The MRI/EEG test will also be performed by direct shock of the V4 complex and checking whether.