Some worrying evidence that the Obama administration may be slipping:
The 2011 FBI primer recommends that FBI agents ask the detaining authority to isolate a detainee "several days before you begin interrogation" as well as during the "multi-session, multi-day [interrogation] process." The primer also repeatedly cites and encourages FBI interrogators to read the 1963 CIA KUBARK manual, a highly controversial document long disavowed and disparaged for its promotion of severe prisoner abuse, including through the use of isolation. Even the KUBARK manual explicitly recognizes the use of isolation in interrogation as a "coercive technique" with profound psychological effects, such as hallucinations and delusions.
The use of isolation as described in the 2011 FBI primer would appear to violate FBI policy.