While reported and observed symptoms are a main way to diagnose either disorder, studies in the 21st century have allowed psychiatrists to use magnetic resonance imaging (MRI) scans to try to find better, definite markers. Through MRIs, psychiatrists can see specific structural differences in the brains of people with schizophrenia. These differences include volume of gray matter, neuropathological size differences variations and cortical thickness, which are associated with cognitive differences on tests.