An altered balance of integrated and segregated brain activity is a marker of cognitive deficits following sleep deprivation
Fig 1
Study design and behavioural results.
(A) Participants made 3 visits to the lab: a habituation night, followed by a counterbalanced design of either another full-night opportunity to sleep (blue) or a night of total SD. In the morning following each night, participants completed RS and cognitive tasks inside the MRI scanner. In the sleep-deprived state (red), participants also had a recovery nap opportunity (yellow) and then recompleted the tasks inside the MRI scanner. (B) Participants completed 3 cognitive tasks inside the scanner in each condition: the ANT, N-back task, and MCT. (C) The preprocessed BOLD time series was concatenated across the 3 tasks, providing one time series for each subject and condition. Task-specific activity (trials for the ANT, blocks for the N-back, and MCT) was modelled with a finite impulse response combined with a hemodynamic response function (black line) and regressed from the time series (blue line) for each parcel to reduce the influence of task-evoked coactivation in subsequent connectivity analyses. (D) Integration was calculated from the covariance matrix of cortical parcels, in a hierarchical manner: across the whole cortex, 7 networks, 17 networks, and 57 clusters. At the cortex level, total integration was calculated as the sum of integration within each of Yeo7 networks and a single measure of integration between networks (between systems). The total integration within each Yeo7 network was calculated as the sum of integration within each of Yeo17 subnetworks and the integration within each of the Yeo17 networks as the sum of integration within each cluster of parcels, as well as a single measure of integration between subnetworks or clusters. ANT, attention network task; BOLD, blood oxygen level dependent; MCT, Mackworth clock task; MRI, magnetic resonance imaging; RS, resting state; SD, sleep deprivation.