Auditory Oddball Deficits in Schizophrenia: An Independent Component Analysis of the fMRI Multisite Function BIRN Study

Abstract

Deficits in the connectivity between brain regions have been suggested to play a major role in the pathophysiology of schizophrenia. A functional magnetic resonance imaging (fMRI) analysis of schizophrenia was implemented using independent component analysis (ICA) to identify multiple temporally cohesive, spatially distributed regions of brain activity that represent functionally connected networks. We hypothesized that functional connectivity differences would be seen in auditory networks comprised of regions such as superior temporal gyrus as well as executive networks that consisted of frontal-parietal areas. Eight networks were found to be implicated in schizophrenia during the auditory oddball paradigm. These included a bilateral temporal network containing the superior and middle temporal gyrus; a default-mode network comprised of the posterior cingulate, precuneus, and middle frontal gyrus; and multiple dorsal lateral prefrontal cortex networks that constituted various levels of between-group differences. Highly task-related sensory networks were also found. These results indicate that patients with schizophrenia show functional connectivity differences in networks related to auditory processing, executive control, and baseline functional activity. Overall, these findings support the idea that the cognitive deficits associated with schizophrenia are widespread and that a functional connectivity approach can help elucidate the neural correlates of this disorder.

Spatial Variance in Resting fMRI Networks of Schizophrenia Patients: An Independent Vector Analysis

“…The differences in weighted amplitudes of these components substantiate findings from previous studies and further strengthen an implication of these neuroanatomical areas in schizophrenia. [29][30][31] We also plotted the amplitude at the voxel of maximum difference for each group for each of these 4 components to ascertain that there existed differences in the observed variance of the groups at these voxels. Figure 2B shows histograms of voxel amplitudes for each group (SZs and HCs) and clearly shows that there exist variance differences even at voxels with mean differences.…”

A Review of the Functional and Anatomical Default Mode Network in Schizophrenia

“…Functional Activity/Deactivation and Connectivity within the DMN in Schizophrenia Activity/Deactivation in the DMN in Schizophrenia Many fMRI studies have demonstrated abnormal activity or deactivation within the DMN areas in patients with schizophrenia during a broad range of tasks, including the auditory oddball task [36][37][38], multi-source interference task [39], working memory task [40][41][42], selective attention task [43], and semantic repetition priming task [44]. Garrity and colleagues [36] first used fMRI to examine the auditory oddball task effects on the DMN in chronic schizophrenia patients.…”

Conserved Functional Connectivity but Impaired Effective Connectivity of Thalamocortical Circuitry in Schizophrenia

“…Abnormal functional magnetic resonance imaging (fMRI) activation of the thalamus in patients with schizophrenia during sensory gating (Tregellas et al, 2007;Tregellas et al, 2009), working memory (Bor et al, 2011), and other executive function (Andrews et al, 2006;Barch, 2005;Minzenberg et al, 2009;Walter et al, 2007) tasks further highlights its role in the illness. Aberrant scalp-recorded electrophysiological indices of sensory gating in schizophrenia (Brockhaus-Dumke et al, 2008;Javitt, 2000;Javitt et al, 1995;Kim et al, 2009;Potter et al, 2006;Salisbury et al, 2002) have also been interpreted as evidence for thalamic dysfunction, given nonhuman research confirming the critical role of the thalamus in similar processes ( Jones, 2007;Krause et al, 2003;McCormick and Bal, 1994;Sherman and Guillery, 2006;Wolf et al, 2010). Additionally, sleep studies have repeatedly identified a decrease in sleep spindle measures in patients with schizophrenia (Ferrarelli et al, 2007;Ferrarelli et al, 2010;Vukadinovic, 2011;Wamsley et al, 2012).…”