The Modulator was researched, designed and created for one purpose and one purpose only: to cause the most suffering possible to a human being.
Its function was simple: to remove the ability of the human mind of regressing into madness, hysteria, unconsciousness or even zoning out, such that the victim’s mind would be ever-present and lucid.
It meant a person going through so much hardship and pain, beyond that which he ever thought possible, only to find that he did not snap. That his mind kept powering on, that despite the sufferings his psyche and body had to endure, the machine of his being would just keep plowing forward. Ceaselessly, with no end in mind.
It would leave him beyond exhausted, hopeless, feverishly hoping for death, but never slipping across the threshold to make suicide a possibility.
Once a the Modulator was removed from the victim (if ever), he was left an empty husk, a shadow of a man. Interestingly enough, the function of the Modulator had an added effect, which was to disable the mysterious part of the brain that served as a tripwire of sorts.
It meant that even after the Modulator was removed, the person would still be in a similar state of endless torture, a drag of a life, till overwhelmed by whatever external force to mercifully end his pitiful and pathetic life.