This is hidden brain.
I'm Shankar Vedantam.
All right, and next up, we have Diana shouting out to the Polensky unit.
Hito, it's mama D.
I know I sound kind of different.
I'm very sick right now.
Got diagnosed with pneumonia.
I've been sick already for quite some time now.
This is the voice of a woman calling into a radio show on the Texas station KPFA.
She has a personal message for a prison inmate.
Anyway, I want to tell you, Rito, that mama Dee loves you.
I always think of you, and it's just getting harder and harder.
I know I'm not supposed to cry because you're going to get mad at me, but I can't help but feel so much love for you.
Calling into a program like this is one of the few ways for spouses and parents and children to communicate with prisoners, especially inmates in solitary confinement.
Many prisoners in solitary have been found guilty of heinous crimes, including murder, rape, terrorism.
But here's something you might not know.
Some are there because they're difficult to manage or because of bureaucratic inertia.
While judges and juries decide whether someone should go to prison, a decision that can be appealed in court, typically, it's prison officials who decide whether someone should be in solitary confinement.
In recent years, both liberals and conservatives, worried about the psychological and financial costs of long term solitary confinement, have raised questions about the practice.
This week on hidden brain, we thought we'd take a look at what happens inside the prison cells that few people ever see and the psychological effects of being alone for long periods of time.