New perspectives for the study of lucid dreaming: From brain stimulation to philosophical theories of self-consciousness

The neural mechanisms underlying lucid dreaming have recently been investigated using brain imaging techniques such as electroencephalography and functional magnetic resonance imaging, which produce insightful but merely correlative results. We propose that research on the neurophysiology of lucid dreaming, for instance concerning the exact relationship between the dorsolateral prefrontal cortex and metacognitive insight into the fact that one is dreaming, should be complemented by methods allowing direct causal interference with neural functioning during sleep. To achieve this aim, several stimulation methods are proposed, i.e. transcranial magnetic stimulation, transcranial direct current stimulation, and galvanic vestibular stimulation. Given the broad range of cognitive and metacognitive processing in dreams, which support a continuous view of lucid and nonlucid dreaming, we further propose that certain aspects of dream lucidity and its neural mechanisms can be investigated in so-called ordinary, nonlucid dreams. This would allow for phenomenologically more comprehensive and practically more efficient experiments in this field of dream research. Such experiments would also provide a solid ground for understanding self-consciousness in lucid and non-lucid dreams, as well as for integrating dream research into more general neurophilosophical theories of consciousness and the self.