Prospective memory and executive function in schizophrenia

Experimental studies of normal subjects have shown that the intention to perform an action speeds word recognition for items related to that intention (Goschke & Kuhl, 1993). This phenomenon--the intention superiority effect (ISE)--is thought to be mediated by frontal executive functions. Since schizophrenia is characteristically associated with forms of frontal-executive dysfunction, an impaired ISE might be expected in this patient group. A script-learning paradigm was used to investigate the ISE in 10 schizophrenics who do show evidence of executive dysfunction and in 10 who do not. As predicted, only the former showed an ISE; however, all schizophrenics showed an ISE to words semantically related to the intention. It seems that the ability to form specific intentions is impaired only in schizophrenics with executive dysfunction; however, they retain the ability to form more generalized intentions.