nested

"Without sustained social interaction, the human brain may become as
impaired as one that has incurred a traumatic injury."
--http://www.boingboing.net/2010/12/17/is-long-term-solitar.html
quoting http://www.newyorker.com/reporting/2009/03/30/090330fa_fact_gawande
which cites a 1992 medical study.

I can't find the study written up anywhere in particular, but cf.
http://www.solitaryconfinement.org/uploads/sourcebook_web.pdf
and http://en.wikipedia.org/wiki/Sremska_Mitrovica_camp

This is all circulating now with regard to this:
http://www.salon.com/news/opinion/glenn_greenwald/2010/12/14/manning/index.html
(it being mainly an irony that Assange was briefly held in solitary
confinement in the UK).