For the last year or so there's been much talk about the fact that the brain apparently spends up to 99% of its energy on apparently useless, task-unrelated activity. Nobody knew what these activity fluctuations were good for and speculations abound. Now there's a new study out from the same lab (Marcus E. Raichle from Washington University at St. Louis) in the journal Neuron. The paper demonstrates that over 70% of human behavioral variability in button press force can be accounted for by these spontaneous brain activity fluctuations.
This of course confirms my earlier hypothesis that it is exactly this type of activity which could underly sponteneous behavior in humans. This reminds me that I have to update my opinion article on "brains as output/input systems" to incorporate this important new finding. It's all getting very solid now so I will probably submit the article for comments also to Nature Precedings soon.
It all comes together very nicely with spontaneous brain activity using most of the brain's energy, because spontaneous behavior is so important for a whole host of evlutionary reasons. We're currently witnessing a huge paradigm shift in the neurosciences. Surely, the dominant input/output paradigm of the brain is coming to an end and makes way for a functional principle of all brains which is centered around spontaneous activity.