gq: Although unpleasantness is an essential part of the IASP definition of pain, it is possible to induce a state described as intense pain devoid of unpleasantness in some patients, with morphine injection or psychosurgery. Such patients report that they have pain but are not bothered by it; they recognize the sensation of pain but suffer little, or not at all. Indifference to pain can also rarely be present from birth; these people have normal nerves on medical investigations, and find pain unpleasant, but do not avoid repetition of the pain stimulus.
Question: IASP's definition of pain includes what aspect as an essential part? Question: What is it possible to induce which is, contrary to expectations, devoid of unpleasantness? Question: Which type of injection has caused patients to report they have pain but aren't bothered by it? Question: How much do some patients going through psychosurgery suffer from the sensation of pain? Question: What perspective towards pain are some people with perfectly normal nerves born with?