Accuracy and completeness of autobiographical memory: evidence from a wearable camera study.

A small wearable camera, SenseCam, passively captured pictures from everyday experience that were later used to evaluate the accuracy and completeness of autobiographical memory. Nine undergraduates wore SenseCams that took pictures every 10 s for two days. After one week and one month, participants first recalled their experiences from specific time periods (timeslices), then reviewed the corresponding pictures to make corrections and report information omitted from initial recall. Results demonstrated the utility of wearable cameras as research tools, and illustrated several characteristics of everyday memory. Recall contents reflected the structure of undergraduate lives. Three different types of omissions were reported: neglected, reminded, and forgotten. Pictures stimulated memory, even for non-visual information (e.g., feelings, thoughts), increasing recall by 23%. The mean completeness of initial recall was 79% (upper bound), with at least 21% forgetting. Accuracy was self-scored by participants (M = 89%), and the mean error rate (11%) provided evidence against strong reconstructive and copy theories of memory. The characteristics of errors shed light on the cognitive processes underlying them. Ratings of recall (confidence, reliving, knowledge, and frequency) supported the episodic/semantic distinction, the dual-process theory of repetition, and reconstructive imagery. Metamemory measures showed a positive correlation between confidence and accuracy.