 It is believed that the same neurological pathways operate in both persons with synesthesia and neurologically normal individuals.These pathways are just exaggerated in those with synesthesia

It has been shown that neurologically normal persons as young as 2.5 years of age demonstrate a type of synesthetic cross-modal associations.In 1929, Wolfgang Köhler ran an experiment in which a group of native Spanish speakers would assign the name “takete” or “baluba” to a set of round or jagged shapes.