People's memories of past events possess different qualitative characteristics, including overall vividness. Certain events are recalled with high clarity and a great degree of detail, whereas other events are barely remembered. Research on the effects of emotion on memory has shown that emotion can play an important role in determining such differences in recall. Positive, negative, and neutral emotions can influence whether an event or information will be richly and vividly recollected. Investigations of emotion and memory have included studies of emotion and general autobiographical memories, eyewitness testimony, flashbulb memories, and memories for traumatic events. This entry examines each of these topics.