Some of the neuronal circuitry of anxiety that has previously been studied in animal models has been uncovered in man using brain imaging techniques. Patients with various types of anxiety disorders have been studied, and common, diverse brain regions have been linked to psychopathology. Findings from a variety of imaging studies were analyzed and summarised. Most anxiety disorders have aberrant brain areas such as the amygdala, anterior cingulate, hippocampus, striatum, and prefrontal cortex, but there are significant variations across anxiety disorders that give a biological basis for a future classification system. Prader-Willi Syndrome (PWS) people have postprandial hyperfunction in the limbic and paralimbic regions of the brain, according to brain imaging studies utilizing functional magnetic resonance imaging.