Wandering Minds and the Default Brain Network

Several news articles have come out today which seem to imply that a recent Science report's main finding is that the mind wanders for a purpose (see this Forbes article), and that "daydreaming improves thinking" (see this Cosmos article). These are typical of fabrications used by popular science journalists to pique the public's interest.

Mason, et al. 2007 (the Science article published today) did not say that the mind wanders for a purpose (though they speculated that there may be one), and specifically mentioned that "the mind may wander simply because it can". Also, I could not find anything about daydreaming improving thinking in the article, except a short sentence about daydreaming possibly improving arousal. (A slap to the face will probably improve arousal; will the next headline be "face slaps improve thinking"?)

The two popular news articles mentioned above present these very speculative statements from the article not only as fact but also as the main results of the research, which I find to be disingenuous.

As a researcher in the area, I would say these are the main points to take from Mason, et al. 2007:

  • It was already known that a set of brain areas in cortex (the 'default network') were consistently more active during "rest" than during task performance. It was not known what these regions were doing, but some thought it may have been daydreaming. Mason, et al. showed that daydreaming is likely what the default network is doing, since this network was more active whenever subjects reported that their mind wandered. (More precisely, the network's activity was correlated with each subject's propensity to daydream.)
  • Rather than using "rest" periods (involving staring at a fixation), Mason, et al. used a practiced task to induce mind wandering. As the Cosmos article put it, "the researchers recognised that our minds often wander while we are engaged in familiar tasks, such as making a tuna fish sandwich, because we don't need to concentrate on it." This, arguably, was a better task to test mind wandering than the typically-used fixation staring since it controlled for more things. For instance, the presence of stimuli between the difficult and practiced tasks was controlled for. However, one could argue that the presence of the task may have contaminated the mind wandering and produced spurious results (e.g. if subjects did the practiced task differently when their mind wandered).
  • The authors acknowledge that other things may be causing the default network activity besides daydreaming: "Reductions in ask difficulty are also likely accompanied by qualitative changes in attention and, perhaps, the implementation of general 'housekeeping' functions."
    Some other possibilities the authors mention (note that these are very speculative!):
      • Increased self-awareness (metacognition), since "people are frequently unaware that their mind is wandering", but the people tested (who scored high on daydreaming) were certainly aware of their own mind wandering.
      • Mind wandering may increase the level of arousal, and thus help with these boring tasks. Thus it might be a strategy used by the subjects to deal with the boring tasks they had to do.
      • It may be that daydreaming "—as a kind of spontaneous mental timetravel—lends a sense of coherence to one’s past,present, and future experiences"
      • It also could be that the network is active "simply because it evolved a general ability to divide attention and to manage concurrent mental tasks."
      • Finally, "the mind may wander simply because it can."

Why did these popular science news articles get things so wrong? Well, as you can see, a lot had to be covered to (hopefully) get it right. It's understandable if some details are left out. However, adding false information or misrepresenting the findings (as the two news articles cited above did) is unacceptable. Science journalists can do better than this.

-MC 

3 Responses to “Wandering Minds and the Default Brain Network”

  1. MWCole Says:

    Despite the problems in the two news articles mentioned, this article at Reuters does a fair job covering the story:

    http://tinyurl.com/ynkhsn

  2. Alex Says:

    Thank You

  3. Neurevolution » Blog Archive » CNS Meeting 2008: Development of Cognitive Control Says:

    [...] on a functional MRI study of 239 individuals ranging from 9 to 97 years of age. She found that the “default-network” brain activity (likely related to mind wandering) was better suppressed during difficult tasks early in life and [...]

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