Neuropsychological indicators of heteromodal cortex (dys)function relevant to conditioned blocking measures of attention in schizophrenia

Abstract

Background. Learning a predictive relationship between two events can block learning about an added event (conditioned blocking; CB). Patients with nonparanoid schizophrenia can show reduced CB and learn about the similar consequences of the added event. Methods. This study reports on the relationship of associative learning and CB measures of attention to signs of heteromodal cortex function provided by performance on a battery of 10 neuropsychological tasks (i.e., frontal, parietal, and temporal lobe function of the left and right hemispheres). Acquisition criteria for the task were achieved by 62 patients with schizophrenia and 62 matched controls but not by 39 other individuals with schizophrenia. Results. First, right hemisphere, visuospatial abilities were generally associated with faster task learning, and patients who could not learn the task were poorer on tests emphasising set-switching abilities associated with left frontal lobe function. Second, CB expression depended on Stroop and Mooney faces task performance that are reported to require cingulate and parietal lobe function. Conclusions. As would be expected, right hemisphere function was implicated in performing a visuospatial learning task. The additional CB requirement incurred additional anterior cingulate and right parietal involvement. Functionally, this probably reflected effortful attentional processes, and illustrates the problems of patients with schizophrenia in switching between automatic and controlled processing strategies.