Lucid dreaming can be learned and offers many potential uses, but research has been hindered by unreliable methods to induce it. This study thoroughly examines three of the most promising cognitive techniques for lucid dream induction, comparing their effectiveness and reliability.
Taking 240 mg of vitamin B6 before bed for five consecutive nights significantly increased how much dream content people remembered, but did not affect dream vividness, bizarreness, or color, nor did it change other sleep measures. A B complex vitamin preparation, by contrast, led to lower self-rated sleep quality and greater tiredness upon waking. The findings replicate and extend a smaller earlier study, suggesting vitamin B6 may be useful in lucid dreaming research.
Two methods are commonly used to measure dream recall at home: retrospective questionnaires (a single question asking people to estimate their recall) and daily logbooks. Retrospective measures tend to yield lower dream recall rates than logbooks. One explanation is that retrospective measures underestimate actual dream recall; another is that keeping a logbook enhances recall. If both effects occur, neither method reflects typical dream recall rates, and each may be confounded with variables linked to underestimation or enhancement. This review addresses the insufficient attention this issue has received.