ABSTRACT
A century ago, Diefendorf and Dodge (1908) ®rst described the phenomenon that patients with schizophrenia have dif®culty accurately maintaining visual gaze on a predictably moving target. Modern research into eye-tracking abnormalities as a neurobiological abnormality representing a possible genetic marker of schizophrenia dates back to the 1970s, when not only patients but also their well relatives were reported to display abnormal eye tracking (Holzman et al., 1974). This chapter describes the major abnormalities of eye tracking reported in patients with schizophrenia and presents data from the Maudsley Family Study of Psychosis, which assessed the utility of eye-tracking dysfunction as an intermediate phenotype by virtue of its presence in unaffected relatives at presumed differing genetic liability.
