Rolling Stone issue 1171 12/6/12
Article about solitary confinement in R/S was haunting. You go into a constant state of anxiety, adrenal gland out of whack, making you ready for action while your frontal cortex atrophies, making your decision making process go all caveman. Your sight gets bad, ocular muscles atrophy from not focusing on distance.
If a psychologist knows this, prison keepers know this.