Cognitive neurobiology of volition and agency in schizophrenia

Publisher Website
Google Scholar
Abstract
IntroductionSince its initial description, schizophrenia has been known to affect volition: voluntary movement (Kraepelin 1919; Zec 1995; McKenna et al. 1998). But such abnormality is not restricted to the way that a movement is performed, it also affects its purpose. Patients may do things abnormally – they may also choose to do abnormal things. In this chapter we address the neural substrates of disordered action performance and the disturbed sense of agency that may occur in some patients with this disabling condition.Volition and willVolition encompasses a spectrum of voluntary behaviours and some of these (‘willed’, ‘intended’ or ‘freely chosen’) seem to us to be quintessentially human. The ‘will’ refers to our capacity to choose. We may ‘choose’ to ‘control’ some of our involuntary impulses. We may choose to attend to one stream of competing information over another. We may initiate conversations, many of which may be structurally unique and unpredictable. We may create a sequence for performing even the most mundane tasks. What we choose to do is an ‘action’; the one who chooses it is an ‘agent’ (Macmurray 1991). One influential theory characterized schizophrenia as a ‘disorder of action’ (Frith 1987). By making action central to schizophrenia, Frith's early theory made the latter a disorder of higher volition – of that which is willed (or chosen) over that which is automatic (Frith 1987; Liddle 1993; see Chapter 10 by Frith). Frith's theories have undergone changes and he currently uses ‘action’ to refer to all movements.