An interesting Journal of Neuroscience paper just out argues that Spontaneous and Task-Evoked Brain Activity Negatively Interact.
If true, this could be explosive, because a lot of neuroscience is built on the assumption that those two things don't interact. So what's going on? We know that the brain is active all of the time. Even if you're not doing anything in particular, there is 'spontaneous' (or resting-state) activation, which varies over time. But what if something in particular does happen, causing brain activation? Is that evoked activity a constant that simply gets added on to the pre-existing activity, or do they interact in some more complex way? The new paper's author, Biyu He, argues as follows. If evoked activity is independent of spontaneous activity and they sum additively, then the variance of the brain activation ought to increase after a stimulus. That's because whatever variability was there spontaneously would still ...
