Torture during interrogation often includes methods that do not physically assault the body or cause actual physical pain - and yet entail severe psychological pain and suffering and profoundly disrupt the senses and personality. Solitary confinement and prolonged sleep deprivation are just two examples of these psychological torture methods. Even psychological methods which do not amount to ill-treatment when considered in isolation, amount to inhuman or degrading treatment or torture, when applied in conjunction with other techniques, cumulatively and/or over a long time. Often they are part and parcel of the whole torture process and constitute a ""background environment'' of harassment and duress. The ""cumulation over time'' factor must thus be considered as part of a system of psychological torture.