 There are many scientific standards in use to determine if a person actually has the genuine neurological condition of lexical-gustatory synesthesia.Scientists check for the behavioral hallmark of a significantly higher retest consistency after at least a year compared to control groups.Another scientific standard method to determine the legitimacy of ones synesthesia is to use Functional magnetic resonance imaging or functional MRI (fMRI) to determine which areas of the brain are active during the scan.