Exploring the Phenomenology of Memory for Pain: Is Previously Experienced Acute Pain Consciously Remembered or Simply Known?

Abstract

Whether or not acute pain is recalled by consciously remembering it or by simply knowing about that past pain as an autobiographical fact, and the degree to which it can be accurately anticipated ("precalled") was investigated using the remember/know paradigm. Cold Pressor (CP) pain was induced in 97 healthy participants who precalled CP pain and then reported their actual experiences of CP pain, using the McGill Pain Questionnaire (MPQ) and a Visual Analogue Scale (VAS). Two weeks later, participants recalled the CP pain and indicated whether each retrospectively selected MPQ descriptor reflected their "remembering" or "knowing" about the pain. Whereas precall ratings significantly underestimated the severity of actual CP pain, recall ratings did not differ significantly from actual CP ratings. Almost three quarters of the MPQ descriptors chosen at recall reflected sensations of CP pain that were clearly, consciously remembered. The proportions of "correct" MPQ descriptors and categories at recall were significantly greater when judged as remembered than when judged as known. These findings suggest that recollections of acute pain at 2 weeks involve episodic memory and to a lesser extent semantic memory, with the former being more accurate. Whether previously experienced pain is clearly, consciously remembered or merely recalled as semantic knowledge about one's personal past has never been empirically investigated. Establishing the relative contribution of different types of memory will allow a better understanding of the phenomenological experience of recalling acute pain.