Task-dependent organization of brain regions active during rest
Abstract:
The human brain demonstrates complex yet systematic patterns of
neural activity at rest. We examined whether functional connectivity
among those brain regions typically active during rest depends
on ongoing and recent task demands and individual differences.
We probed the temporal coordination among these regions
during periods of language comprehension and during the rest
periods that followed comprehension. Our findings show that the
topography of this ..rest network.. varies with exogenous processing
demands. The network encompassed more highly interconnected
regions during rest than during listening, but also when
listening to unsurprising vs. surprising information. Furthermore,
connectivity patterns during rest varied as a function of recent
listening experience. Individual variability in connectivity strength
was associated with cognitive function: more attentive comprehenders
demonstrated weaker connectivity during language comprehension,
and a greater differentiation between connectivity
during comprehension and rest. The regions we examined have
generally been thought to form an invariant physiological and
functional network whose activity reflects spontaneous cognitive
processes. Our findings suggest that their function extends beyond
the mediation of unconstrained thought, and that they play an
important role in higher-level cognitive function.