Solitary confinement is 'damaging and unnecessary'

Experts in the fields of law, neuroscience, and psychology used this year's annual meeting of the American Association for the Advancement of Science to decry the use of solitary confinement in US prisons.

Prof Craig Haney, from the University of California, Santa Cruz, has been studying conditions in US prisons since the late 1970s, and in particular the impacts that long periods of isolation can have on inmates' state of mind.

He spoke to our correspondent Jonathan Amos.