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What the brain does by itself: The role of endogenous brain activity in resting state functional connectivity studiesResting state functional connectivity studies discovered coherent patterns of brain activity in the absence of a cognitive task, but the function of so-called ‘resting state networks’ that are connected by these patterns remains controversial. This poster outlines two views on the functional role of these networks: the direct role and enabling condition view. Bechtel (2013) argues that resting state networks could play a direct role in cognition and behavior, because endogenous brain activity can modulate information processing. I argue that Bechtel overlooks the alternative position that endogenous brain activity contributes to the maintenance of functional systems in the brain, which is an enabling condition for cognitive processing (Raichle 2015).
Firstly, I reconstruct Bechtel’s argument for the direct role view, according to which the containing system for functional analysis (Cummins 1975) is the behaving organism. Endogenous brain activity directly contributes to cognition by modulating the processing of behaviorally relevant information. For example: electrophysiological experiments have shown that endogenous theta-oscillations in rat hippocampi play a role in tracking the trajectory of the animal during spatial navigation (O’Keefe and Reece 1993).
Secondly, I show that Bechtel’s examples from resting state functional connectivity studies do not support the direct role view so clearly. Recent experiments suggest that that the default mode network plays a direct role in mind-wandering, and endogenous somatomotor activity a direct role in motor control. The main issue with this interpretation is that activity in both networks remains stable during sleep and anesthesia, when online cognition or overt behavior is absent (Raichle 2015).
Thirdly, I claim that the enabling condition view can better account for this stability of endogenous brain activity because it takes the living brain, and not the behaving organism as the containing system for functional analysis. Functional system pathways need to be constantly maintained, independently of the presence of cognitively relevant information processing. This view is further supported by consistent metabolic levels within several resting state networks, suggesting that cellular repair and synaptic remodeling are coordinated at the system level (Raichle 2015).
The poster concludes that both the direct role and enabling condition view are empirically supported by current resting state studies. However, whereas the direct role view predicts that a particular information processing aspect (e.g., duration of mind-wandering) is disrupted when endogenous network activity is disturbed, the enabling condition view would not predict such a selective effect. Further experimental work is needed to test either of these predictions.
Bechtel, Will. 2013. “The Endogenously Active Brain: The Need for an Alternative Cognitive Architecture.” Philosophia Scientiae 17: 3–30.
Cummins, Robert. 1975. “Functional Analysis”. The Journal of Philosophy 72: 741–765.
O'Keefe, John and Michael L. Recce (1993). “Phase Relationship between Hippocampal Place Units and the EEG Theta Rhythm”. Hippocampus. 3: 317–330.
Raichle, Marcus E. 2015. “The Restless Brain. How Intrinsic Activity Organizes Brain Function.” Transactions of the Royal Society London B. 370: 1–8. DOI: 10.1098/rstb.2014.0172
Berlin School of Mind and Brain, Max Planck Institute for Human Cognitive and Brain Sciences