Aberrant Frontoparietal Function during Recognition Memory in Schizophrenia: A Multimodal Neuroimaging Investigation

Abstract

Prefrontal-parietal networks are essential to many cognitive processes, including the ability to differentiate new from previously presented items. As patients with schizophrenia exhibit structural abnormalities in these areas along with well documented decrements in recognition memory, we hypothesized that these patients would demonstrate memory-related abnormalities in prefrontal and parietal physiology as measured by both functional magnetic resonance imaging and magnetoencephalography (MEG). Medicated outpatients with schizophrenia (n ϭ 18) and age-matched healthy control subjects (n ϭ 18) performed an old-new recognition memory task while physiological data were obtained. Whereas controls exhibited strong, bilateral activation of prefrontal and posterior parietal regions during successful identification of old versus new items, patients exhibited greatly attenuated activation of the right prefrontal and parietal cortices. However, within the patient group, there was strong correlation between memory performance and activation of these right-sided regions as well as a tight correlation between old-new effect-related activations in frontal and parietal regions, a pattern not seen in control subjects. Using MEG, control subjects-but not patients-exhibited a sequential pattern of old Ͼ new activity in the left posterior parietal cortex and then right prefrontal cortex; however, patients uniquely exhibited old Ͼ new activity in right temporal cortex. Collectively, these findings point to markedly different distributions of regional specialization necessary to complete the old-new item recognition task in patients versus controls. Inefficient utilization of prefrontal-parietal networks, with compensatory activation in temporal regions, may thus contribute to deficient old-new item recognition in schizophrenia.

Multimodal imaging of repetition priming: Using fMRI, MEG, and intracranial EEG to reveal spatiotemporal profiles of word processing

“…A blocked design was selected in order to increase the SNR, optimizing our ability to detect very subtle BOLD changes associated with repetition priming in anterior and ventral temporal lobe regions that are known to be susceptible to signal loss (Chee et al, 2003; Dale et al, 2000). Although numerous studies have reported highly similar patterns of activations between blocked and event-related fMRI designs using lexical-semantic tasks (Chee et al, 2003; Pilgrim et al, 2002; Wagner et al, 2005; Weiss et al, 2009), blocked presentation of items may induce strategies or lead to greater levels of habituation in some regions relative to event-related designs. This may explain the bilateral precuneus and lateral occipitotemporal activations seen in our fMRI data that were not apparent with MEG.…”

“…Reliable decreases in blood-oxygen level dependent (BOLD) responses are consistently reported in left ventral occipitotemporal, posterior temporal, and left inferior frontal cortex—regions implicated in word form identification (Allison et al, 1999), lexical access, and semantic processing (Marinkovic et al, 2003; Matsumoto et al, 2005). Repetition of words also has been associated with increased activity in bilateral precuneus, frontoparietal, and hippocampal cortex—regions implicated in resting state and episodic retrieval processes (Weiss et al, 2009). What it not clear from fMRI is precisely when repetition effects occur during the course of word processing.…”

Dysconnectivity in the Frontoparietal Attention Network in Schizophrenia

“…For example, this frontoparietal network (FPN) is activated in tasks ranging from set-shifting (16) to feature selection (17) and object orientation (18) as well as recognition memory (19), working memory (20) and attention [for reviews see Ref. (21–23)].…”

Aberrant neural networks for the recognition memory of socially relevant information in patients with schizophrenia

“…However, deficits in recognition memory that were related to nonsocial contexts were not directly compared in this study. Some studies have reported evidence of deficits in recognition memory that is related to nonsocial contexts as well (Kim, Kwon, Kang, Youn, & Kang, 2004; Weiss et al., 2009). Therefore, this viewpoint should be supported by the results of a task involving both social and nonsocial contexts, which should be able to determine whether the deficits were prominent during social contexts.…”