Illuminating consciousness during sleep via real-time dialogue with sleepers

After waking from a sound sleep, we typically remember little of what transpired during the night. The common assumption is thus that sleep is unconscious. Yet, what is recalled in the morning offers only the tiniest glimpse into the Pandora’s box of our sleeping minds. For instance, repeatedly awakening individuals to probe the last thing on their mind reveals frequent experiences across sleep stages. Further, studies of brain responses reveal sophisticated environmental processing during sleep. During fleeting moments, sleepers can even respond to questions using subtle signals, like twitching. We propose to take advantage of this real-time dialogue with sleeping people to get a first-hand glimpse into the sleeping mind, unobscured by the memory deficits that usually shield us from knowing what happens each night. Our first project will first elucidate why sleeping people communicate inconsistently. By studying sleepers’ responses to analogous questions posed in three different sensory modalities, we will test whether responsiveness is bottlenecked by global variations in markers of consciousness or by modality-specific sensory disconnection. Our novel response methodology will also allow us to detect whether sleepers form the intention to respond, regardless of their behavioral responses. Next, we will initiate communication throughout a full night’s sleep to query sleepers about conscious experiences in all sleep stages. By posing questions that require a metacognitive judgment, we can directly evaluate how metacognition, a process closely linked with higher order aspects of consciousness, changes throughout sleep. Immediately after responding, sleepers will be awoken to report their experiences to assess whether sleepers report conscious access of responses given. This synergistic combination of methods has the potential to reveal previously intractable mysteries of the sleeping mind, such as the nature of experiences forgotten upon awakening.