Christopher Frith and Shaun Gallagher Models of the Pathological Mind Introduction Christopher Frith is a research professor at the Functional Imaging Laboratory of the Wellcome Department of Imaging Neuroscience at University College, Lon- don. He explores, experimentally, using the techniques of functional brain imag- ing, the relationship between human consciousness and the brain. His research focuses on questions pertaining to perception, attention, control of action, free will, and awareness of our own mental states and those of others. As the follow- ing discussion makes clear, Frith investigates brain systems involved in the choice of one action over another and in the understanding of other people. Such investigations are aimed at understanding brain basis of autism and schizophrenia. In his widely cited study of schizophrenia, The Cognitive Neuropsychology of Schizophrenia (1992), Frith argues that many of the positive symptoms of schizophrenia, such as delusions of control, auditory hallucinations, and thought insertion, involve problems of self-monitoring. Patients, in effect, lose track of their own intentions and mistakenly attribute agency for their own actions to someone else. Frith employs models of motor control, involving comparator mechanisms and efference copy, not only to explain delusions that involve move- ment, but also to develop a neurocognitive explanation of delusional cognition. One of the central aspects of motor control involves a forward model, a non- conscious pre-motor system operating prior to the actual execution of movement and its sensory feedback. This forward mechanism, Frith argues, generates a conscious sense of agency for action. This is consistent with research that corre- lates initial awareness of action with recordings of the lateralized readiness potential and with transcranial magnetic stimulation of the supplementary motor area. One’s initial awareness of a spontaneous voluntary action depends on this forward mechanism. Schizophrenics, however, have problems with this forward Journal of Consciousness Studies, 9, No. 4, 2002, pp. 57–80 Correspondence: Christopher Frith, Wellcome Dept. of Cognitive Neurology, Institute of Neurology, Queen Square, London WC1N 3BG. Email: cfrith@fil.ion.ucl.ac.uk Shaun Gallagher, Department of Philosophy, Canisius College, Buffalo, NY 14208, USA. Email: Gallaghr@Canisius.edu