Essay 7 in Monkeyluv, “Why Are Dreams Dreamlike” discusses how our frontal cortex is often completely offline during REM sleep – while we are dreaming. In the introduction to the second part of the book, Sapolsky states that chapter 7 will also discuss how in “every one of us it (the frontal cortex) is completely dysfunctional, shut down, and out of business many times each day.” However, the chapter talks strictly about when the prefrontal cortex is shut off during dreams, and does not touch on these “many times each day” portion. I am interested to know the other times throughout the day that this area of the brain is offline. Are there triggers which cause it to be completely dysfunctional – certain events, fatigue, neurotransmitters? What are the advantages to giving this section of the brain a break? Are there individual differences which would cause some people’s frontal cortices to be shut down more or less than others’? Since Sapolsky dropped the ball, maybe one of you can help!
In this same vein, I wonder how similar brain activity is during a day dream compared to a REM dream – maybe while the mind wanders, or day dreams, the frontal cortex takes a breather just like it would during a REM dream.
Hey Amy- when I read this I thought Sapolsky was referring to the multiple times each night when we are in REM sleep as the times the prefrontal cortex is offline instead of separate instances when this happens. That would be interesting to know when else, if ever, the prefrontal cortex is offline though!
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I think that works quite nicely… especially if you’re having daydreams in which you march into your bosses office and tell them to… well, tell them off. It’s like you’re giving your prefrontal cortex a break while you indulge in secret fantasies of doing the stuff it keeps from doing all day.
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Ah! Offline prefrontal cortex and daydreaming! Sounds a lot like the Default Mode Network idea to me. Last semester I wrote a paper on the idea that when we engage in wakeful task-negative introspection (aka daydreaming) a part of our prefrontal cortex does in fact go off-line. I find the entire concept fascinating. For a good review take a look here:
http://www.pnas.org/content/105/10/4028.full
And here:
Or Google “A default mode of brain function: a brief history of an evolving idea”
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