This project is somewhat open ended. It studies several papers to develop some insights into the importance of the co-existence of brain structures possessing characteristic scales with scale-invariant (power law dependence on separation) correlation function and power-distributed bursts of brain activity.
Recall the discussion in Sec. 2.1. In [136], analysis of fMRI scans of the brain found that the BOLD activity in the brain lacks a characteristic scale. Scale invariance and criticality is described in [281] as crucial for a healthy brain.
From the same type of scans it is routinely concluded that the brain possesses welldefined structures, see Fig. 2 in [463] consisting of brain regions particularly involved in certain tasks such as vision and motion. These regions appear to form collaborative networks, see Fig. 3 in [463] and [72].
(a) Try to think about how the BOLD signal of fMRI, when averaged over time and space, can lead to a scale-invariant correlation function while when analysed as in [463] it allows the identification of characteristic spatial regions. 

In agreement with the observed behaviour of the BOLD correlation function [136], indications of scale-invariant brain dynamics were also seen at the microscale of bursts of neuronal firing [56] and at the macroscale of BOLD signal activity [433].
(b) Try to think about how the burst activity needs to be organised in space and time in order to be able to be described by a scale-free correlation function and also at the same time to exhibit spatial structures and networks when analysed as in [72, 463].