Reduced Medial Prefrontal–Subcortical Connectivity in Dysphoria: Granger Causality Analyses of Rapid Functional Magnetic Resonance Imaging

Abstract

A cortico-limbic network consisting of the amygdala, medial prefrontal cortex (mPFC), and ventral striatum (vSTR) has been associated with altered function in emotional disorders. Here we used rapidly sampled functional magnetic resonance imaging and Granger causality analyses to assess the directional connectivity between these brain structures in a sample of healthy and age-matched participants endorsing moderate to severe depressive symptomatology as they viewed a series of natural scene stimuli varying systematically in pleasantness and arousal. Specifically during pleasant scene perception, dysphoric participants showed reduced activity in mPFC and vSTR, relative to healthy participants. In contrast, amygdala activity was enhanced to pleasant as well as unpleasant arousing scenes in both participant groups. Granger causality estimates of influence between mPFC and vSTR were significantly reduced in dysphoric relative to control participants during all picture contents. These findings provide direct evidence that during visual perception of evocative emotional stimuli, reduced reward-related activity in dysphoria is associated with dysfunctional causal connectivity between mPFC, amygdala, and vSTR.

Granger causality analysis reveals distinct spatio-temporal connectivity patterns in motor and perceptual visuo-spatial working memory

“…Over the last years, GC analysis (Granger, 1969 ) has been applied in several studies, mainly in fMRI (see e.g., Roebroeck et al, 2005 ; Rypma et al, 2006 ; Sridharan et al, 2008 ; Florin et al, 2010 ; Gao et al, 2011 ; Hamilton et al, 2011 ; Liao et al, 2011 ; Miao et al, 2011 ; Zhou et al, 2011 ; Al-Aidroos et al, 2012 ; Tang et al, 2012 ; Wen et al, 2012 ; Wu et al, 2013 ; Zhang and Li, 2013 ; Sabatinelli et al, 2014 ; Yang and Shu, 2014 ) and (considerably fewer) in EEG (Chávez et al, 2003 ; Hesse et al, 2003 ; Gow et al, 2008 ; Keil et al, 2009 ; Dauwels et al, 2010 ; Barnett and Seth, 2011 ; Barrett et al, 2012 ; Nicolaou et al, 2012 ; de Tommaso et al, 2013 ; Wu et al, 2013 ).…”

Narrative comprehension beyond language: Common brain networks activated by a movie and its script

“…In the movie condition of our experiment the dialog was represented with natural speech. A previous fMRI study by Moreno et al [ 42 ] employing natural and scrambled speech stimulus have revealed BOLD signal decrease in the precuneus, PHG, middle and inferior frontal gyri and parietal inferior lobule during natural speech comprehension. IC1 encompasses those regions and might therefore reflect its involvement in the comprehension of the natural speech (for movie dialogues) and imagery of the natural speech (for written dialogues).…”

Repeated noninvasive stimulation of the ventromedial prefrontal cortex reveals cumulative amplification of pleasant compared to unpleasant scene processing: A single subject pilot study

“…More precisely, the vmPFC shows increased activation patterns specifically for stimuli with pleasant content in comparison to unpleasant or neutral stimuli [3][4][5][6][7][8]. Furthermore, several psychiatric disorders were shown to be linked-amongst others-to dysfunctional processing in vmPFC regions [9][10][11][12][13].…”