What are we speaking about when we speak about “rest”?

By combining different neuroimaging methodologies (EEG, fMRI), we ask the question of what is the default state of the human brain, and in general how can we disentangle different states of mind which occur spontaneously.

The answer to our question seems to be sleep. The freely wandering, resting mind moves (fast) towards sleep. By analysing a large (>1000) number of fMRI datasets with a sleep decoder based on support vector machines, we revealed a strong prevalence of sleep throughout the resting state imaging literature.

 

 

Journal reference:

Tagliazucchi, E. & Laufs, H. (2014). Decoding wakefulness levels from typical fMRI resting state data reveals reliable drifts between wakefulness and sleep. Neuron.