Memory for pain.

How does memory handle previous experiences of pain? We asked this exciting question when we were analyzing the results of a study which was designed to examine the risk factors for the development of chronic pain in women treated surgically for breast cancer (1). The multifactorial Bayesian model indicated the intensity of the previous acute postoperative pain as remembered by the patient on top of the model. A prospective study was then designed to explore the relationship between acute and chronic pain and also to find out how the patient’s memory for the previous pain changes with time (2). The study revealed that patients will remember their past pains in a very different manner: the memory for the intensity of previous postoperative pain may diminish or it may increase. Which factors will determine which direction is taken by the memory?