Phase lag indeX (PLI), a measure of phase locking between two signals, was calculated between all combinations of EEG channels, and channel pairs constituting the top 30% of PLI values, a threshold at which the results match well with those of model network, were chosen as the functional connections of the network [50].

The time scale of our study lies in between these two extreme limits, where the functional connectivity can reflect underlying structural connectivity yet the effect of local dynamics on the network structure can be disregarded.

For the functional connection in the network, we use two types of phase coherence measures; (1) mean phase coherence (PC) and (2) phase lag indeX (PLI).

PLI was used to define the functional connectivity in the EEG network [50].

Finally, the results we present here provide a co-activation based view of emotion representation that can inform models of functional connectivity .

However, co-activation is not the same as functional connectivity .

However, these latter studies omitted the brainstem (and note that “the functional connectivity of the brainstem should be investigated in the future”).