Functional connectivity reveals inefficient working memory systems in post-traumatic stress disorder

Working memory processing of traumatic material in women with pottraumatic stress disorder

“…28 However, previous studies using a similar paradigm with nontraumatic material did not report medial parietal decreases in patients when performing working memory tasks. 9,10,12,13 This discrepancy between our results and those reported in these latter studies may be related to their use of a 1-back task in which participants only had to maintain the last item in memory, whereas in our study participants had to maintain and constantly update the 3 last items perceived. Thus, the previous absence of evidence of parietal midline deactivation may be explained by relatively low cognitive demands (as compared with our 3-back task), resulting in a lesser amount of default mode network J Psychiatry Neurosci 2012;37(2) mobilization in both groups and subthreshold betweengroup variations in these regions.…”

“…8 Neuroimaging studies have suggested frontal and parietal dysfunction as a source for working memory alterations in patients wtih PTSD with an under-recruitment of dorsolateral frontal 9,10 and posterior parietal sites, 10 which are classically associated with the n-back task in healthy participants. 11 Moreover, frontoparietal functional connectivity appears to be altered when patients perform working memory tasks, 12,13 showing a lack of differentiation between the networks implicated in the maintenance and the updating of information in patients with PTSD.…”

Frontostriatal Involvement in Task Switching Depends on Genetic Differences in D2 Receptor Density

“…Various studies showed increased functional connectivity in clinical populations associated with performance deficits in cognitive tasks (Schlösser et al, 2003(Schlösser et al, , 2008Meyer-Lindenberg et al, 2005;Shaw et al, 2009). In addition, decreased task-related coupling in clinical conditions such as schizophrenia is presumably compensated by increased connectivity in other networks (Friston, 1998;Stephan et al, 2006;Spoletini et al, 2009).…”

Trait Anxiety Modulates the Neural Efficiency of Inhibitory Control

“…The finding is consistent with earlier reports showing the importance of DLPFC connectivity for executive control functions in psychiatric samples. Abnormal coupling or "disconnection" (Friston, 1998) has been linked to pathological cognitive processing in disorders such as schizophrenia (Meda et al, 2009;Meyer-Lindenberg et al, 2005;Schlösser et al, 2003), depression ( Vasic et al, 2009;, and anxiety (Etkin et al, 2009;Shaw et al, 2009). In the Stroop task, the functional coupling of DLPFC with the fusiform gyrus during incongruent trials is likely related to the top-down suppression of task-irrelevant stimulus features (i.e., word form or identity), while participants are engaged in color naming (cf.…”

“…This assumption is motivated by recent studies that demonstrated an important role of differences in interregional coupling for optimal versus suboptimal or even pathological cognitive processing, for example, for high as compared with low intelligence (Neubauer & Fink, 2009b) and for psychiatric disorders such as schizophrenia (Meda, Stevens, Folley, Calhoun, & Pearlson, 2009;Spoletini et al, 2009;Stephan, Baldeweg, & Friston, 2006;Meyer-Lindenberg et al, 2005;Schlösser et al, 2003;Friston, 1998), depression (Vasic, Walter, Sambataro, & Wolf, 2009;, and anxiety disorders (Etkin, Prater, Schatzberg, Menon, & Greicius, 2009;Shaw et al, 2009). Of greatest relevance to the present study is the finding that anxiety-related personality traits are accompanied by reduced amygdalaprefrontal connectivity in emotion regulation tasks requiring cognitive control for the modulation of an affective response (Cremers et al, 2010;Kienast et al, 2008;Passamonti et al, 2008).…”