Characterizing variation in the functional connectome: promise and pitfalls

Abstract

The functional MRI (fMRI) community has zealously embraced resting state or intrinsic functional connectivity approaches to mapping brain organization. Having demonstrated their utility for charting the large-scale functional architecture of the brain, the field is now leveraging task-independent methods for the investigation of phenotypic variation and the identification of biomarkers for clinical conditions. Enthusiasm aside, questions regarding the significance and validity of intrinsic brain phenomena remain. Here, we discuss these challenges and outline current developments that, in moving the field toward discovery science, permit a shift from cartography toward a mechanistic understanding of the neural bases of variation in cognition, emotion and behavior.

Subspecialization in the human posterior medial cortex

“…Hence, the PMC regions did not engage any common brain region or network during task-related information processing, while they conjointly engaged a well-characterized network during task-unrelated information processing. These findings also emphasize that a dichotomic brain segregation into clear-cut “task-positive” and “task-negative” brain regions probably constitutes an undue oversimplification (Bzdok et al, 2013b; Eickhoff et al, in press; Kelly et al, 2012; Murphy et al, 2009). That is because the PrC exhibited both “task-negative” properties, for example, in its functional coupling with DMN regions at rest in the present study, as well as “task-positive” properties, for example, in earlier studies on regional cerebral blood flow in humans measured by arterial spin labeling (Pfefferbaum et al, 2011) and functional connectivity patterns in monkeys (Margulies et al, 2009).…”

Neurocognitive Decoding of Aesthetic Appreciation

“…It is possible to find reinforcing reports on the validity of the DMN hypothesis in relation to aesthetics, and the fact that RSN closely resembles that of functional systems identified during task performance is not unique to this field (Kelly et al 2012). When actively looking for the time-course dynamics of aesthetic experience, similarities with the DMN have been reported to occur only during a late time window of 1 s after the stimulus onset Cela-Conde et al 2013).…”

Anhedonia correlates with abnormal functional connectivity of the superior temporal gyrus and the caudate nucleus in patients with first-episode drug-naive major depressive disorder

“…RSFC captures spontaneous neural activity that coincides temporally to form neural networks and is useful in understanding brain network dynamics (Kelly et al, 2012). Decreased RSFC in fronto-striatal-limbic circuits and increased RSFC within cortical networks have been frequently reported in patients with MDD (Kaiser et al, 2015;Wang et al, 2012).…”