Synaesthesia On March 2, 2001 I finally found out the name for something I have experienced for as long as I can remember! It was synaesthesia! Synaesthesia is when the brain connects two or more sensory reactions. For me it shows as numbers, letters, words and time units having colors. For example, when I think of 7 it's yellow in my head. 4 is also yellow while 2 is red and 8 is dark blue and ...