Despite my best efforts to stop it, my most productive planning always occurs in the last five minutes of a yoga class. Relax my mind? I don’t think so! What goes on in the brain when we let our minds wander? Mason et al. report that a network of brain structures is active during daydreaming in a recent article in Science.

The authors had people do repetitive (i. e. boring) tasks, like memorizing and rehearsing the same short list of words forward and backward, for 30 minutes each day. The subjects reported that their minds wandered more during this task than when they were given a new task to do. On the fifth day, the subjects did the same task in an MRI machine. The authors identified regions of the brain that were active during this literally mind-numbing activity relative to those that were active when participants worked on a novel task. Then they correlated the activity of these brain regions to the participants’ daydream frequencies. BOLD signal in the medial prefrontal cortex, cingulate, precuneus, right superior frontal gyrus and the left and right insula associated with daydreaming. In addition to daydreaming, the authors believe that these brain regions might be important in ‘housekeeping’ functions or might cause people to be aware of their daydreams.

Why do we daydream? I’ll look that up once I stop thinking about a beach vacation…