What we have learned so far is that the occurrence of lucid dreaming seems to be facilitated by brain maturational processes, in particular the integration of the frontal lobes into the cortico-cortical and cortico-thalamic networks, as outlined in thesis no. 1. Moreover, in lucid dreaming arising out of REM sleep, the apparent spatial dissociation between two states of arousal, waking (rostral) and sleep (caudal) is accompanied by the phenomenological dissociation expressed in an altered conscious awareness, for example, by changing from a first-person to a third-person perspective. This observation has led us to propose that lucid dreaming is to be regarded as a hybrid state (thesis No. 2) within a state-space continuum (thesis No. 3). Another observation concerns changes in frequency-specific oscillatory activity, with significant increases in lower gamma band activity in lucid dreams, suggesting that lower gamma band activity plays an important role in achieving and/or maintaining a lucid dream. By electrically stimulating the dreaming brain in this frequency band we have been successful in trying to elicit lucid dreams, suggesting a causal role for the gamma frequency band, perhaps not only in lucid dreaming but in higher-order consciousness per se (thesis No. 4).
In spite of this basic scientific progress, our conclusions are only speculative and in need of experimental testing. One future line of research might be the spatial networking involved in consciousness. In our research, we have only stimulated the brain through bilateral fronto-temporal stimulation. We found only lower gamma band activity to be successful in inducing lucid dreaming. What happens, however, when we use different frequencies in rostral and caudal areas? Another question in need of attention is that of applicability. Will wake-training in gamma band activity through Neurofeedback and/or tACS increase the rate of lucid dreaming? What about effects on higher cognitive functions? Finally, we hope that our findings might some day be implemented in clinical settings. This concerns, for example, comatose or locked-in patients who are, through their trauma, confined to a particular state and who may benefit from the possibility of maximally utilizing state capacities.
We have now reviewed and discussed the current state of the art with respect to lucid dreaming. Having been very skeptical at first about whether such research could be conducted at all using a rigorous scientific protocol, we have grown increasingly optimistic—if not enthusiastic—about the prospects for the study of lucid dreaming, allowing us to monitor the brain as the mind changes conscious states. In that spirit, lucid dream science may be likened to a moon landing: yes it was hard to achieve, but we did it, and returned to tell the tale.