 In 1998 Hyman and his co-authors, P. Usita and K. Herman conducted a study on the effects of progressive Alzheimer's disease on the ability to recall life events.They listened to personal narratives from 6 person's with the disease and six without, and recorded the various memory failures, repetitions and organizational methods of each group.They found that those with Alzheimer's Disease had a marked deficiency in their ability to adequately recall past significant events.