The results may therefore be consistent with different neurochemical theories of the effects of schizophrenia on MMN, considering N-Methyl-D-aspartate (NMDA) antagonists (Javitt, 2000; Heekeren et al., 2008) and the serotonin receptor (5HT2A) as an agonist giving a model of psychoses that display distinct neurocognitive profiles (Heekeren et al., 2008). Here, HTR2A is linked to schizophrenia.