The Dream Catcher experiment: Blinded analyses disconfirm markers of dreaming consciousness in EEG spectral power

Abstract

The Dream Catcher test defines the criteria for a genuine discovery of the neural constituents of phenomenal consciousness. Passing the test implies that some patterns of purely brain-based data directly correspond to the subjective features of phenomenal experience, which would help to bridge the explanatory gap between consciousness and brain. Here, we conducted the Dream Catcher test for the first time in a graded and simplified form, capturing its core idea. The experiment involved a Data Team, who measured participants’ brain activity during sleep and collected dream reports, and a blinded Analysis Team, who was challenged to predict better than chance, based solely on brain measurements, whether or not a participant had a dream experience. Using a serial-awakening paradigm, the Data Team prepared 54 one-minute polysomnograms of NREM sleep—27 of dreamful sleep (3 from each of the 9 participants) and 27 of dreamless sleep—redacting from them all associated participant and dream information. The Analysis Team attempted to classify each recording as either dreamless or dreamful using an unsupervised machine learning classifier, based on hypothesis-driven, extracted features of EEG spectral power and electrode location. The procedure was repeated over five iterations with a gradual removal of blindness. At no level of blindness did the Analysis Team perform significantly better than chance, suggesting that EEG spectral power does not carry any signatures of phenomenal consciousness. Furthermore, we demonstrate an outright failure to replicate key findings of recently reported correlates of dreaming consciousness.HighlightsThe first reported attempt of the Dream Catcher test.The correlates of conscious experience may not lie in EEG spectral power.Reported markers of NREM dreaming consciousness misperformed in a blinded setting.Those markers also could not be confirmed in an unblinded setting.

Does the mind wander when the brain takes a break? Local sleep in wakefulness, attentional lapses and mind-wandering

“…For example, local modulations of slowwave activity within NREM and REM sleep have been associated with the occurrence of dreams (Siclari et al, 2016). Specifically, a decrease in the number of slow waves (which can be interpreted as a regional reduction of sleep depth) in parietal regions is associated with subjective reports of dreaming upon awakening, although the causal nature of this relationship is debated (Boly et al, 2017;Wong et al, 2019). The spatio-temporal properties of the decrease in slow-wave activity are predictive not only of the occurrence of dreams but also of their content (Siclari et al, 2016) (e.g.…”

Does the Mind Wander When the Brain Takes a Break? Local Sleep in Wakefulness, Attentional Lapses and Mind-Wandering

“…For example, local modulations of slow-wave activity within NREM and REM sleep have been associated with the occurrence of dreams (Siclari et al, 2016). Specifically, a decrease in the number of slow waves (which can be interpreted as a regional reduction of sleep depth) in parietal regions is associated with subjective reports of dreaming upon awakening, although the causal nature of this relationship is debated (Boly et al, 2017; Wong et al, 2019). The spatio-temporal properties of the decrease in slow-wave activity are predictive not only of the occurrence of dreams but also of their content (Siclari et al, 2016) (e.g., a decrease in slow-wave activity in motor regions was associated with more reports of movements during dreams).…”

The Neural Correlates of Dreaming Have Not Been Identified Yet. Commentary on “The Neural Correlates of Dreaming. Nat Neurosci. 2017”

“…Some studies partially replicated the Siclari et al ( 2017) results (D'Atri et al, 2019;Scarpelli et al, 2019Scarpelli et al, , 2020 while some didn't. The recent Wong et al (2019) study failed to observe any significant difference between the "dream recall" vs. "no dream recall" condition. Using the same serial awakening paradigm, their blinded analyses disconfirmed markers of dreaming consciousness in EEG spectral power.…”