DMN Again and Again

* Jonathan Smallwood, Boris C. Bernhardt, Robert Leech, Danilo Bzdok, Elizabeth Jefferies and Daniel S. Margulies, ‘The Default Mode Network in Cognition: A Topographical Perspective’, Nature Reviews Neuroscience, 22 (2021), 503-13.
* Yaara Yeshurun, Mai Nguyen and Uri Hasson, ‘The Default Mode Network: Where the Idiosyncratic Self Meets the Shared Social World’, Nature Reviews Neuroscience, 22 (2021), 181-92.

The Default Mode Network (DMN) has been with me all the way through this blog. It is a set of brain regions which earned its name when it was noticed that activity continued there when other attention-demanding tasks were not in progress — when the brain reverted to a sort of default mode. It became associated with inward-turned processes such as mind-wandering, for example, and I got really keen on that, writing various posts (e.g. here), and a lecture that got published in the Journal of the British Academy.
      Naturally I am interested when there is further research on the DMN, and here we have two recent papers in Nature Reviews Neuroscience that show scientists still tackling quite fundamental questions. Smallwood et al. consider the ‘topographical characteristics’ of the DMN — what do its component parts seem to be linked to by proximity? — and zero in on the auditory system which, they suggest, ‘allows these regions of the DMN to capitalize on the capacity for language processes to organize cognitive function, perhaps through the vehicle of inner speech’. So when our minds wander — or perhaps in dreaming — there may be some sense of an ‘inner voice’ involved, or so the physical contiguities suggest, at least.
      Yeshurun et al. are interested in how the brain ‘integrates incoming extrinsic information with prior intrinsic information to form rich, context-dependent models of situations as they unfold over time’. They propose that the DMN is not simply involved in looking inwards; instead it is ‘central for integrating external and internal information, allowing for shared communication and alignment tools, shared meanings, shared narratives and, above all, shared communities and social networks’. And as they aptly notice, this is about as ‘default’ as it gets, a fundamental aspect of human cognition. Scientists are interested in the ways that the DMN links things up — and so am I. It appears that many key questions are open, though.
      There is still a process of catch-up in these posts; it is enjoyable sifting through the things I have been missing. I am allowing myself to hope that soon I will feel able to take The Turn and begin putting some literary examples into the mix, with their own questions to ask and answers to give.

E-mail me at rtrl100[at]cam.ac.uk

1 thought on “DMN Again and Again

  1. Ellen Spolsky

    See also G. Gabrielle Starr, Feeling Beauty: The Neuroscience of Aesthetic Experience, MIT Press, 2013 for interesting speculation and some empirical evidence on the DMN –

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.