title: ADHD and schizophrenia phenomenology: visual scanpaths to emotional faces as a potential psychophysiological marker?
abstract: Commonalities in the clinical phenomenology and psychopharmacology of ADHD and schizophrenia are reviewed. The potential of psychostimulants to produce psychotic symptoms emphasizes the need for objective psychophysiological distinctions between these disorders. Impaired emotion perception in both disorders is discussed. It is proposed that visual scanpaths to facial expressions of emotion might prove a potentially useful psychophysiological distinction between ADHD and schizophrenia. There is consistent evidence that both facial affect recognition and scanpaths to facial expressions are impaired in schizophrenia, with emerging empirical evidence showing that facial affect recognition is impaired in ADHD also. Brain imaging studies show reduced activity in the medial prefrontal and limbic (amygdala) brain regions required to process emotional faces in schizophrenia, but suggest more localized loss of activity in these regions in ADHD. As amygdala activity in particular has been linked to effective visual scanning of face stimuli, it is postulated that condition-specific breakdowns in these brain regions that subserve emotional behavior might manifest as distinct scanpath aberrations to facial expressions of emotion in schizophrenia and ADHD.
authors.affiliation: Western Clinical School, The Brain Dynamics Centre, University of Sydney, Sydney, NSW, Australia. pamelam@psych.usyd.edu.au
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Marsh
authors.forename: Leanne M
authors.initials: LM
authors.lastname: Williams
mesh_terms: D000679:Amygdala / Q000503:physiopathology; D001288:Attention; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism / Q000523:psychology; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D003937:Diagnosis, Differential; D004192:Discrimination, Psychological; D004298:Dopamine / Q000378:metabolism; D004644:Emotions; D005133:Eye Movements; D005149:Facial Expression; D006801:Humans; D008032:Limbic System / Q000503:physiopathology; D010364:Pattern Recognition, Visual; D017397:Prefrontal Cortex / Q000503:physiopathology; D011601:Psychophysics; D021641:Recognition, Psychology; D012559:Schizophrenia / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism; D012565:Schizophrenic Psychology
chemical_list: D000697:Central Nervous System Stimulants; D004298:Dopamine