Is dream recall underestimated by retrospective measures and enhanced by keeping a logbook? An empirical investigation.

Retrospective questionnaires asking people how often they remember dreams produce lower recall rates than daily logbooks, a gap called the retrospective-logbook disparity. One explanation is that retrospective measures underestimate true dream recall; another is that keeping a logbook boosts recall. This study tested both possibilities using several retrospective and logbook measures across three logbook types. The disparity correlated with variables tied to retrospective underestimation and was larger among participants who reported improved recall during the logbook period. The findings suggest that retrospective measures underestimate dream recall and that keeping a logbook enhances it. Recommendations for using each measurement method are offered.

Study at a glance

Abstract

In a recent review, Aspy, Delfabbro, and Proeve (2015) highlighted the tendency for retrospective measures of dream recall to yield substantially lower recall rates than logbook measures, a phenomenon they termed the retrospective-logbook disparity. One explanation for this phenomenon is that retrospective measures underestimate true dream recall. Another explanation is that keeping a logbook tends to enhance dream recall. The present study provides a thorough empirical investigation into the retrospective-logbook disparity using a range of retrospective and logbook measures and three different types of logbook. Retrospective-logbook disparities were correlated with a range of variables theoretically related to the retrospective underestimation effect, and retrospective-logbook disparities were greater among participants that reported improved dream recall during the logbook period. These findings indicate that dream recall is underestimated by retrospective measures and enhanced by keeping a logbook. Recommendations for the use of retrospective and logbook measures of dream recall are provided.