The uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist ketamine has been proposed as a model system of the symptoms of schizophrenia. To complement this model system and to allow neurobiological as well as translational studies, biomarkers are often applied to people under the influence of ketamine. Here, we apply oculomotor, perceptual and cognitive biomarkers to healthy human volunteers whilst they undergo BOLD fMRI at 3 Tesla field strength. We use a counter-balanced, placebo-controlled, double-blind, within-subjects design. A sample of 25 healthy participants is required. Participants will receive intravenous (IV) racemic ketamine (with a 100ng/ml target plasma concentration) on one of two assessment days and they will receive placebo (intravenous saline) on the other assessment day. BOLD fMRI will be carried out on a Siemens Trio scanner at the Life&Brain Centre, Bonn. In addition to brain functional and cognitive, perceptual and oculomotor responses, we will also measure self-ratings of psychosis-like experiences. These will be obtained using the Psychotomimetic States Inventory (PSI; Mason et al 2008).