A Correspondence between Individual Differences in the Brain's Intrinsic Functional Architecture and the Content and Form of Self-Generated Thoughts

Abstract

Although neural activity often reflects the processing of external inputs, intrinsic fluctuations in activity have been observed throughout the brain. These may relate to patterns of self-generated thought that can occur while not performing goal-driven tasks. To understand the relationship between self-generated mental activity and intrinsic neural fluctuations, we developed the New York Cognition Questionnaire (NYC-Q) to assess the content and form of an individual's experiences during the acquisition of resting-state fMRI data. The data were collected as a part of the Nathan Kline Rockland Enhanced sample. We decomposed NYC-Q scores using exploratory factor analysis and found that self-reported thoughts clustered into distinct dimensions of content (future related, past related, positive, negative, and social) and form (words, images, and specificity). We used these components to perform an individual difference analysis exploring how differences in the types of self-generated thoughts relate to whole brain measures of intrinsic brain activity (fractional amplitude of low frequency fluctuations, regional homogeneity, and degree centrality). We found patterns of self-generated thoughts related to changes that were distributed across a wide range of cortical areas. For example, individuals who reported greater imagery exhibited greater low frequency fluctuations in a region of perigenual cingulate cortex, a region that is known to participate in the so-called default-mode network. We also found certain forms of thought were associated with other areas, such as primary visual cortex, the insula, and the cerebellum. For example, individuals who reported greater future thought exhibited less homogeneous neural fluctuations in a region of lateral occipital cortex, a result that is consistent with the claim that particular types of self-generated thought depend on processes that are decoupled from sensory processes. These data provide evidence that self-generated thought is a heterogeneous category of experience and that studying its content can be helpful in understanding brain dynamics.

Shaped by our thoughts – A new task to assess spontaneous cognition and its associated neural correlates in the default network

“…Combining the Shape Expectations task with concurrent fMRI or electroencephalography recording techniques to track the temporal course of mind wandering represents an area of immense interest for future studies. Nevertheless, our findings highlight the utility of combining out-of-scanner behavioural measures with resting state functional connectivity data, in keeping with previous reports in the literature (Gorgolewski et al, 2014;.…”

On the relation of mind wandering and ADHD symptomatology

“…For instance, as noted in the Introduction, some recently identified dimensions of mind wandering include its temporal focus (Smallwood, Nind, & O'Connor, 2009), level of awareness (Schooler, 2002), and valence , to name a few. In each case, these dimensions have been shown to predict unique variance in independent outcomes such as neural activity (Gorgolewski et al, 2014), mood , and, in the present case, ADHD symptoms. Thus, the acknowledgment of a multiplicity of states within the construct of mind wandering might well explain one of the fundamental paradoxes of mind wandering: namely, that for some individuals, mind wandering is a source of unhappiness and error (Killingsworth & Gilbert, 2010;McVay & Kane, 2009;respectively), and for others, a source of creativity and constructive thought (Baird et al, 2012;Kaufman & Singer, 2011).…”

“…Although the aforementioned evidence and argument provide grounds to hypothesize that mind wandering is a central feature of ADHD, counterarguments are provided by recent research that has reported that at least some aspects of mind wandering are linked to patience , controlled processing (Gorgolewski et al, 2014), and premeditation (Smallwood, Nind, & O'Connor, 2009), all of which are often thought to be antithetical to ADHD characteristics. Moreover, mind wandering has been linked to a reduction in external distraction (Barron, Riby, Greer, & Smallwood, 2011), whereas ADHD is thought to be associated with greater distraction from external sources (Barkley, Koplowitz, Anderson, & McMurray, 1997).…”

Thinking too much: self-generated thought as the engine of neuroticism

“…Multivoxel pattern analysis demonstrated that neural patterns in the mPFC determined the emotional content of SGT [32]. A large-scale individual-differences study exploring the neural correlates of the content of SGT at rest indicated that individuals whose experiences were less positive in tone (akin to being highly neurotic) exhibited greater activity in regions of the mPFC-PCC that are associated with conscious perception of threat [33]. Fitting with these findings is work showing that DMN brain regions were more active during induced worry compared with a neutral condition and that neuroticism correlated positively with the amount of everyday worrying and also with the generation of more worryrelated thoughts following exposure to a worry-inducing sentence [34].…”