TY - GEN ID - cogprints2051 UR - http://cogprints.org/2051/ A1 - Bender, A1 - Müller, A1 - Oades, A1 - Sartory, Y1 - 2001/// N2 - Introduction: Measures of selective attention processing like latent inhibition (LI) and conditioned blocking (CB) are disturbed in some patients with schizophrenia. (LI is the delay in learning about the associations of a stimulus that has been associated with no event [vs. de novo learning]; CB is the delay in learning the associations of a stimulus-component when the other component has already started to acquire these associations.) We proposed, - a) to replicate the reported decreases of CB in patients without paranoid-hallucinatory symptoms, b) to see if CB depends on the age of illness-onset and its duration, as reported for LI. Methods: We studied 101 young and old, acute and chronically ill patients with schizophrenia, of whom 62 learned a modified 'mouse-in-house' CB task, and compared them with 62 healthy controls matched for age, education and socio-economic background. Results: 1/ CB was more evident in patients with a diagnosis of paranoid schizophrenia than other subtypes. 2/ An unusual persistence of high CB scores through testing was associated with productive symptoms (including positive thought disorder). 3/ Reduced CB related to the increased expression of a) Schneider's first rank symptoms of ideas-of-reference and b) to negative symptoms like poor rapport and poor attention. 4/ CB was less evident in the older patients (age range 9.5-63.3y) and those with an earlier illness-onset (range 8.5-45.8y). Conclusions: In contrast to the similar LI test of selective attention CB is found in patients with paranoid schizophrenia and, unlike LI, the expression of CB by patients with schizophrenia is not related closely to illness-duration. Reduced CB tended to be found in those with an earlier onset, a group often noted for more severe cognitive problems. These results imply that CB and LI reflect the activity of different underlying processes. We suggest that reduced CB on the first few test-trials in nonparanoid schizophrenia reflects the unusual persistence of controlled information processing strategies that would normally become automatic during conditioning. In contrast continued CB during testing in patients with positive (paranoid) symptoms reflects an unusual persistence of automatic processing strategies. PB - Elsevier KW - attention KW - conditioned blocking KW - Kamin blocking KW - schizophrenia KW - paranoid KW - nonparanoid KW - thought-disorder KW - disorganized KW - onset KW - illness-duration KW - ideas-of-reference KW - passivity KW - delusions KW - learning TI - Conditioned blocking and schizophrenia: a replication and study of the role of symptoms, age, onset-age of psychosis and illness-duration SP - 157 AV - public EP - 170 ER -