 Bertrand and Spanos (1984) were able to study the process of memory recall by hypnotizing a group of undergraduate students, teaching the students three lists of words, and compelling the students to forget certain parts of these lists.They discovered that clustering related information together during initial learning may play a significant role in memory recall.In another experiment, Davidson and Bower (1991) found that participants with selective amnesia due to hypnosis were able to remember all non-amnesic information with near perfect recall.