it has been shown that the conditions of these secure housing units have severe mental and psychological effects on prisoners. prisoners in shus are isolated for long periods of time. instances of assault and torture against these prisoners in response to trivial things have also been cited. social isolation housing, can reduce environmental stimulation, and causes a feeling of loss of control over all aspects of a prisoner's daily life. these environmental risks include but are not limited to hypersensitivity to stimuli, distortions and hallucinations, increased anxiety and nervousness, diminished impulse control, severe and chronic depression, appetite loss and weight loss, heart palpitations, talking to oneself, problems sleeping, nightmares, self-mutilation, difficulties with thinking, concentration, and memory, and lower levels of brain function. researchers at mcgill university paid a group of male graduate students to stay in small chambers that were to replicate solitary confinement cells. this study was to conduct an experiment on sensory deprivation and how it can cause psychiatric disorders while in solitary confinement as you are deprived of most of your senses in there. the plan was to observe these students for six weeks, but none lasted more than seven days. the common justification by officials is that prisoners of certain natures deserve to be punished for the threat that they pose to society. this can be attributed to the fear of increasing crime rates and therefore, support the government's effort to enforce harsher forms of punishment.