Brain response abnormalities during verbal learning among patients with schizophrenia

Patients with schizophrenia often show verbal teaming deficits that have been linked to the pathophysiology of the disorder and result in functional impairment. This study examined the biological basis of these deficits by comparing the brain response of patients with schizophrenia (n = 17) to that of healthy comparison participants (n = 14) during a verbal paired-associates teaming task using functional magnetic resonance imaging (fMRI). Brain response during new word teaming was examined within and between groups in two a priori regions of interest, the inferior frontal gyrus and hippocampus, and across the whole brain. In regions of group difference, we also examined the relationship of brain response during teaming to later recall of the word pairs. Despite successful matching of levels of word-pair recall, patients' brain response during new teaming was abnormal in bilateral regions within the inferior frontal gyrus, a small region in left posterior hippocampus, and other areas within the frontal, parietal and temporal cortex compared with healthy individuals. In some regions, but not in the hippocampus, patients with the most normal brain response also remembered the most word pairs following scanning. Thus, verbal teaming deficits found among patients with schizophrenia appear to be related to hypofunction of distributed brain networks. (c) 2007 Elsevier Ireland Ltd. All rights reserved.