Neural substrates of rumination tendency in non-depressed individuals

Abstract

a b s t r a c tThe tendency to ruminate, experienced by both healthy individuals and depressed patients, can be quantified by the Ruminative Response Scale (RRS). We hypothesized that brain activity associated with rumination tendency might not only occur at rest but also persist to some degree during a cognitive task. We correlated RRS with whole-brain fMRI data of 20 healthy subjects during rest and during a face categorization task with different levels of cognitive demands (easy or difficult conditions). Our results reveal that the more subjects tend to ruminate, the more they activate the left entorhinal region, both at rest and during the easy task condition, under low attentional demands. Conversely, lower tendency to ruminate correlates with greater activation of visual cortex during rest and activation of insula during the easy task condition. These results indicate a particular neural marker of the tendency to ruminate, corresponding to increased spontaneous activity in memory-related areas, presumably reflecting more internally driven trains of thoughts even during a concomitant task. Conversely, people who are not prone to ruminate show more externally driven activity.

Ruminative brooding is associated with salience network coherence in early pubertal youth

“…Despite evidence implicating all three networks in rumination in adults (Berman et al , 2011, 2014; Hamilton et al , 2011; Kuhn et al , 2012, 2014; Piguet et al , 2014; Luo et al , 2015), we found that coherence of SN, but not of DMN or ECN, was associated with brooding. The SN, which includes the anterior insula, dACC, and frontopolar regions, receives afferent inputs from subcortical and limbic structures involved in emotion processing and in motivation (Menon, 2011), as well as autonomic inputs (Craig, 2002).…”

“…Indeed, high-ruminating adults exhibit stronger SN-ECN connectivity (Kuhn et al , 2012) than do their low-ruminating peers. Thus, it is possible that in girls who exhibit higher levels of brooding, when the SN, which is already strongly coherent, integrates with the DMN and ECN, the DMN and ECN may not be equipped for the strength and potentiation of the SN activation, which may explain the over-coherence within DMN and under-coherence within ECN that has been found to be associated with ruminative brooding in adults (Berman et al , 2011; Hamilton et al , 2011, 2014; Kuhn et al , 2012; Piguet et al , 2014; Luo et al , 2015). …”

“…The DMN is involved in self-referential and memory consolidation processes, SN is implicated in orienting towards novel, potentially threatening, stimuli, and ECN is involved in inhibiting the persevative thinking that characterizes rumination and shifting individuals’ cognitive sets to another line of thought (Menon, 2011). The most robust evidence linking intrinsic networks with rumination has been documented for the DMN; adult studies converge to indicate that high ruminators have stronger connectivity between regions within the DMN than do their low-rumination counterparts (Berman et al , 2011, 2014; Hamilton et al , 2011; Piguet et al , 2014; Luo et al , 2015). High ruminating adults also evidence greater connectivity within the SN (Kuhn et al , 2014) and decreased connectivity within the ECN (Kuhn et al , 2012).…”

Affective neuroscience of self‐generated thought

“…Similarly, individuals with anxiety commonly exhibit hyperactivity of the salience network during anxiety‐provoking tasks . During external attentional tasks involving nonemotional stimuli, both depressed individuals and nondepressed individuals who ruminate fail to fully deactivate key default network regions . This pattern of hyperactivity is accompanied by increases in resting‐state functional connectivity among key default network regions; reduced connectivity between the medial prefrontal cortex and the nucleus accumbens and amygdala; and biased coupling of frontoparietal control systems with the default network and away from the dorsal attention network .…”

Trait Rumination Influences Neural Correlates of the Anticipation but Not the Consumption Phase of Reward Processing

“…The pars triangularis of the IFG, or more broadly the ventrolateral prefrontal cortex (vlPFC; Ridderinkhof et al, 2004) has a central role in inhibitory control (Swick et al, 2011), specifically in the inhibition of irrelevant or negative information from short-term memory (Berman et al, 2011), and has an important function in memory retrieval (Badre and Wagner, 2007). This brain area is among the most frequently activated regions in connection with rumination (Piguet et al, 2014). These findings are also convergent with the results of Kühn et al (2013), who detected greater left IFG activations among those non-depressed people who tend to experience intrusive thoughts (Kühn et al, 2013).…”