Background and significance: Overview: Synesthesia is an intriguing neurological disease that is relatively rare and understudied. This comes in many different forms, but the common denominator among all variations is "the automatic activation of unusual competing experiences in response to ordinary inducing stimuli." In other words, stimulation of one sensory system causes a response in a different, unrelated sensory system. The study of this phenomenon can provide a better understanding of the different sensory systems and their integration. Understanding synesthesia is important for learning about the underlying brain structures and the development of our senses. Grapheme-color synesthesia is the most common form of synesthesia in which people visualize 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. Additionally, a study by Jäncke et. al suggests that synesthesia may be caused by increased structural connectivity and more cortical material in the fusiform gyrus and areas of the V4 complex. A study by Rouw et. al also found a greater presence of white matter in the inferior temporal cortex in synesthetes, and greater hyperconnectivity in those who could project colors into the outside world compared to those who could only visualize colors in their minds . This distinction implies that synesthesia is likely caused by abnormalities in brain development, and research by Simner et. al suggests that a basic level of cognition is required before these associations can be formed. Whether this difference in brain matter is caused genetically or in some other way is largely unknown. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get the original essay Main hypothesis: I hypothesize that grapheme color synesthesia is the result of an abnormal genetic accumulation of neuronal connections in the inferior temporal cortex and nearby areas. 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, inf. temp. cortex), and will attempt to perform fractional anisotropy measurements in these regions to determine the volume and composition of the neuronal connection. To determine whether grapheme-color synesthesia has a genetic basis, these tests will also be carried out with the blood relatives of those affected who give consent. Rationale: These experiments will be performed assuming that 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 increased brain activity via 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 identify new ones. Invasive EEG monitoring will also be used for the same purpose by measuring currents indicating neuronal activity in these regions when stimulated. Furthermore, a statistically significant increase..