Nir, Y., Tononi, G., Dreaming and the brain: from phenomenology to neurophysiology. Trends Cogn Sci, 14, 2010, 88.
Siclari, F., LaRocque, J.J., Postle, B.R., Tononi, G., Assessing sleep consciousness within subjects using a serial awakening paradigm. Front Psychol 4 (2013), 1–9.
Stickgold, R., Malia, A., Fosse, R., Hobson, J.A., Brain-mind states: I. Longitudinal field study of sleep/wake factors influencing mentation report length. Sleep 24 (2001), 171–179.
Tononi, G., Boly, M., Cirelli, C., Consciousness and sleep. Neuron, 2024, 1568–1594.
Killingsworth, M.A., Gilbert, D.T., A wandering mind is an unhappy mind. Science, 330, 2010, 932.
Ward, A.F., Wegner, D.M., Mind-blanking: when the mind goes away. Front Psychol, 4, 2013, 59718.
Chun, M.M., Golomb, J.D., Turk-Browne, N.B., A taxonomy of external and internal attention. Annu Rev Psychol 62 (2011), 73–101.
Kam, J.W.Y., Handy, T.C., The neurocognitive consequences of the wandering mind: a mechanistic account of sensory-motor decoupling. Front Psychol, 4, 2013, 725.
Seli, P., Kane, M.J., Smallwood, J., Schacter, D.L., Maillet, D., Schooler, J.W., Smilek, D., Mind-wandering as a natural kind: a family-resemblances view. Trends Cogn Sci 22 (2018), 479–490.
Barron, E., Riby, L.M., Greer, J., Smallwood, J., Absorbed in thought: the effect of mind wandering on the processing of relevant and irrelevant events. Psychol Sci 22 (2011), 596–601.
Gold, J., Ciorciari, J., A review on the role of the neuroscience of flow states in the modern world. Behav Sci, 10, 2020, 137.
Smallwood, J., Fitzgerald, A., Miles, L.K., Phillips, L.H., Shifting moods, wandering minds: negative moods lead the mind to wander. Emotion 9 (2009), 271–276.
Yanko, M.R., Spalek, T.M., Driving with the wandering mind: the effect that mind-wandering has on driving performance. Hum Factors 56 (2014), 260–269.
Smallwood, J., Beach, E., Schooler, J.W., Handy, T.C., Going AWOL in the brain: mind wandering reduces cortical analysis of external events. J Cogn Neurosci 20 (2008), 458–469.
Cirelli, C., Tononi, G., The many unknowns of partial sensory disconnection during sleep: a review of the literature. Clin Transl Neurosci, 8, 2024, 9 In this review paper, the mechanisms behind partial sensory disconnection across different sensory modalities during sleep are reviewed, drawing on studies in both animals and humans. They highlight the limited understanding of sensory gating in the brain during nonrapid and REM sleep and discuss the roles of neuromodulators like noradrenaline in this phenomenon.
Freud, S., The Interpretation of Dreams. 1899, Franz Deuticke.
BERGER, R.J., Experimental modification of dream content by meaningful verbal stimuli. Br J Psychiatry 109 (1963), 722–740.
Ellman SJ, Antrobus JS: The Mind in Sleep: Psychology and Psychophysiology; 1991.
Leslie, K., Ogilvie, R., Vestibular dreams: the effect of rocking on dream mentation. Dreaming 6 (1996), 1–16.
Nielsen, T.A., Changes in the kinesthetic content of dreams following somatosensory stimulation of leg muscles during REM sleep. Dreaming 3 (1993), 99–113.
Schredl, M., Atanasova, D., Hörmann, K., Maurer, J.T., Hummel, T., Stuck, B.A., Information processing during sleep: the effect of olfactory stimuli on dream content and dream emotions. J Sleep Res 18 (2009), 285–290.
Salvesen, L., Capriglia, E., Dresler, M., Bernardi, G., Influencing dreams through sensory stimulation: a systematic review. Sleep Med Rev, 74, 2024, 101908 In this systematic review, the authors examine how sensory stimulation during sleep influences dream content. They find that although stimuli across different sensory modalities can affect dreams, the precise mechanisms remain unclear due to significant methodological limitations in existing research. They emphasize the need for studies combining dream report collection and neuroimaging to better understand how external stimuli can modulate dreaming.
Colrain, I.M., Campbell, K.B., The use of evoked potentials in sleep research. Sleep Med Rev 11 (2007), 277–293.
Kakigi, R., Naka, D., Okusa, T., Wang, X., Inui, K., Qiu, Y., Tran, T.D., Miki, K., Tamura, Y., Nguyen, T.B., et al. Sensory perception during sleep in humans: a magnetoencephalograhic study. Sleep Med 4 (2003), 493–507.
Campbell, K.B., Colrain, I.M., Event-related potential measures of the inhibition of information processing: II. The sleep onset period. Int J Psychophysiol 46 (2002), 197–214.
Errando, C.L., Sigl, J.C., Robles, M., Calabuig, E., García, J., Arocas, F., Higueras, R., Del Rosario, E., López, D., Peiró, C.M., et al. Awareness with recall during general anaesthesia: a prospective observational evaluation of 4001 patients. Br J Anaesth 101 (2008), 178–185.
Moerman, N., Bonke, B., Oosting, J., Awareness and recall during general anesthesia. Facts and feelings. Anesthesiology 79 (1993), 454–464.
Osterman, J.E., Hopper, J., Heran, W.J., Keane, T.M., van der Kolk, B.A., Awareness under anesthesia and the development of posttraumatic stress disorder. Gen Hosp Psychiatry 23 (2001), 198–204.
Pandit, J.J., Cook, T.M., Jonker, W.R., O'Sullivan, E., A national survey of anaesthetists (NAP5 Baseline) to estimate an annual incidence of accidental awareness during general anaesthesia in the UK. Anaesthesia 68 (2013), 343–353.
Linassi, F., Zanatta, P., Tellaroli, P., Ori, C., Carron, M., Isolated forearm technique: a meta-analysis of connected consciousness during different general anaesthesia regimens. Br J Anaesth 121 (2018), 198–209.
Brice, D.D., Hetherington, R.R., Utting, J.E., A simple study of awareness and dreaming during anaesthesia. Br J Anaesth 42 (1970), 535–542.
Sanders, R.D., Gaskell, A., Raz, A., Winders, J., Stevanovic, A., Rossaint, R., Boncyk, C., Defresne, A., Tran, G., Tasbihgou, S., et al. Incidence of connected consciousness after tracheal intubation: a prospective, international, multicenter cohort study of the isolated forearm technique. Anesthesiology 126 (2017), 214–222.
Lennertz, R., Pryor, K.O., Raz, A., Parker, M., Bonhomme, V., Schuller, P., Schneider, G., Moore, M., Coburn, M., Root, J.C., et al. Connected consciousness after tracheal intubation in young adults: an international multicentre cohort study. Br J Anaesth 130 (2023), e217–e224 This study investigates the incidence of connected consciousness — awareness with the ability to behaviorally respond to commands — following tracheal intubation in young adults aged 18–40 years. Using the IFT, the study finds that 11% of subjects exhibited connected consciousness after intubation, with a higher incidence in females (13%) compared to males (6%).
Russell, I.F., The Narcotrend ‘depth of anaesthesia’ monitor cannot reliably detect consciousness during general anaesthesia: an investigation using the isolated forearm technique. BJA Br J Anaesth 96 (2006), 346–352.
K. Leslie, Dreaming during anesthesia, Conscious Aware Anesth, 2010, 74 - 89. doi:10.1017/CBO9780511676291.005.
Noreika, V., Jylhänkangas, L., Móró, L., Valli, K., Kaskinoro, K., Aantaa, R., Scheinin, H., Revonsuo, A., Consciousness lost and found: subjective experiences in an unresponsive state. Brain Cogn 77 (2011), 327–334.
Radek, L., Kallionpää, R.E., Karvonen, M., Scheinin, A., Maksimow, A., Långsjö, J., Kaisti, K., Vahlberg, T., Revonsuo, A., Scheinin, H., et al. Dreaming and awareness during dexmedetomidine- and propofol-induced unresponsiveness. Br J Anaesth 121 (2018), 260–269.
Leslie, K., Skrzypek, H., Paech, M.J., Kurowski, I., Whybrow, T., Dreaming during anesthesia and anesthetic depth in elective surgery patients: a prospective cohort study. Anesthesiology 106 (2007), 33–42.
Leslie, K., Sleigh, J., Paech, M.J., Voss, L., Lim, C.W., Sleigh, C., Dreaming and electroencephalographic changes during anesthesia maintained with propofol or desflurane. Anesthesiology 111 (2009), 547–555.
Ramsøy, T.Z., Overgaard, M., Introspection and subliminal perception. Phenomenol Cogn Sci 3 (2004), 1–23.
Sandberg, K., Bibby, B.M., Timmermans, B., Cleeremans, A., Overgaard, M., Measuring consciousness: task accuracy and awareness as sigmoid functions of stimulus duration. Conscious Cogn, 20, 2011.
Konkoly, K.R., Appel, K., Chabani, E., Mangiaruga, A., Gott, J., Mallett, R., Caughran, B., Witkowski, S., Whitmore, N.W., Mazurek, C.Y., et al. Real-time dialogue between experimenters and dreamers during REM sleep. Curr Biol 31 (2021), 1417–1427.e6.
Overgaard, M., Sandberg, K., Kinds of access: different methods for report reveal different kinds of metacognitive access. Philos Trans R Soc B Biol Sci, 367, 2012.
Peels, R., The empirical case against introspection. Philos Stud 173 (2016), 2461–2485.
Questienne, L., van Dijck, J.P., Gevers, W., Introspection of subjective feelings is sensitive and specific. J Exp Psychol Hum Percept Perform 44 (2018), 215–225.
Ramm, B.J., First-person experiments: a characterisation and defence. Rev Philos Psychol 9 (2018), 449–467.
Overgaard, M., Sandberg, K., The Perceptual Awareness Scale—recent controversies and debates. Neurosci Conscious 2021 (2021), 1–8.
Lohse, M., Overgaard, M., Emotional priming depends on the degree of conscious experience. Neuropsychologia 128 (2019), 96–102.
Sandberg, K., Timmermans, B., Overgaard, M., Cleeremans, A., Measuring consciousness: is one measure better than the other?. Conscious Cogn 19 (2010), 1069–1078.
Overgaard, M., Fehl, K., Mouridsen, K., Bergholt, B., Cleeremans, A., Seeing without seeing? Degraded conscious vision in a blindsight patient. PLoS One, 3, 2008, e3028.
Casagrande, M., Violani, C., Lucidi, F., Buttinelli, E., Bertini, M., Variations in sleep mentation as a function of time of night. Int J Neurosci 85 (1996), 19–30.
Dement, W., Kleitman, N., The relation of eye movements during sleep to dream activity: an objective method for the study of dreaming. J Exp Psychol 53 (1957), 339–346.
Goodenough, D.R., Lewis, H.B., Shapiro, A., Jaret, L., Sleser, I., Dream reporting following abrupt and gradual awakenings from different types of sleep. J Pers Soc Psychol 2 (1965), 170–179.
Kahan, T.L., LaBerge, S.P., Dreaming and waking: similarities and differences revisited. Conscious Cogn 20 (2011), 494–514.
Fosse, R., Stickgold, R., Hobson, J.A., Brain-mind states: reciprocal variation in thoughts and hallucinations. Psychol Sci 12 (2001), 30–36.
Nieminen, J.O., Gosseries, O., Massimini, M., Saad, E., Sheldon, A.D., Boly, M., Siclari, F., Postle, B.R., Tononi, G., Consciousness and cortical responsiveness: a within-state study during non-rapid eye movement sleep. Sci Rep 6 (2016), 1–10.
Brown, E.N., Lydic, R., Schiff, N.D., General anesthesia, sleep, and coma. N Engl J Med 363 (2010), 2638–2650.
Smith, G., D'Cruz, J.R., Rondeau, B., Goldman, J., General anesthesia for surgeons. StatPearls, 2023.
Cecconi, B., Montupil, J., Mortaheb, S., Panda, R., Sanders, R.D., Phillips, C., Alnagger, N., Remacle, E., Defresne, A., Boly, M., et al. Study protocol: Cerebral characterization of sensory gating in disconnected dreaming states during propofol anesthesia using fMRI. Front Neurosci, 18, 2024, 1306344 In this article, a detailed fMRI protocol is proposed to study sensory disconnection within-state during propofol sedation, aiming to avoid biases from contrastive analyses, by delivering auditory stimuli and collecting subjective reports upon awakening. The stimulation paradigm, experimental design, and planned analyses with the aim to investigate the fMRI correlates of sensory disconnection are thoroughly described.
Cecconi, B., Riedner, B., Smith, R., Annen, J., Laureys, S., Tononi, G., Boly, M., Baird, B., High density EEG signatures of connected vs disconnected consciousness during REM sleep. European Journal of Neurology, 2022, WILEY.
Krom, A.J., Marmelshtein, A., Gelbard-Sagiv, H., Tankus, A., Hayat, H., Hayat, D., Matot, I., Strauss, I., Fahoum, F., Soehle, M., et al. Anesthesia-induced loss of consciousness disrupts auditory responses beyond primary cortex. Proc Natl Acad Sci USA 117 (2020), 11770–11780.
Scheinin, A., Kantonen, O., Alkire, M., Långsjö, J., Kallionpää, R.E., Kaisti, K., Radek, L., Johansson, J., Sandman, N., Nyman, M., et al. Foundations of human consciousness: imaging the twilight zone. J Neurosci 41 (2021), 1769–1778.
Casey, C.P., Tanabe, S., Farahbakhsh, Z., Parker, M., Bo, A., White, M., Ballweg, T., Mcintosh, A., Filbey, W., Saalmann, Y., et al. Distinct EEG signatures differentiate unconsciousness and disconnection during anaesthesia and sleep. Br J Anaesth 128 (2022), 1006–1018 In this study, the authors use a serial awakening paradigm and collect subjective reports upon awakening to differentiate between sensory disconnection and unconsciousness during sedation with dexmedetomidine and propofol, as well as during natural sleep. They contrast these conditions with wakefulness to identify the hd-EEG neural correlates of each state. Their findings reveal that sensory disconnection is linked to broad neural changes, while unconsciousness is characterized by focal decreases in the cingulate cortices.
Valli, K., Radek, L., Kallionpää, R.E., Scheinin, A., Långsjö, J., Kaisti, K., Kantonen, O., Korhonen, J., Vahlberg, T., Revonsuo, A., et al. Subjective experiences during dexmedetomidine- or propofol-induced unresponsiveness and non-rapid eye movement sleep in healthy male subjects. Br J Anaesth 131 (2023), 348–359 This study explores the similarities between anesthetic-induced unresponsiveness and non-REM sleep at the experiential level by interviewing subjects after recovery from anesthesia. The findings reveal that both states produce comparable rates of conscious experiences (69.7% after anesthesia, 64.4% after sleep), primarily disconnected, dream-like in nature. Despite the absence of systematic sensory stimulation, memory incorporation of the research setting is common in both conditions. The estimates reported in this paper might be conservative, as the reports are collected only after recovery and may be biased by amnestic effects.
McCormick, D.A., Bal, T., Sensory gating mechanisms of the thalamus. Curr Opin Neurobiol 4 (1994), 550–556.
Nourski, K.V., Steinschneider, M., Rhone, A.E., Kawasaki, H., Howard, M.A., Banks, M.I., Auditory predictive coding across awareness states under anesthesia: an intracranial electrophysiology study. J Neurosci 38 (2018), 8441–8452.
Sanders, R.D., Casey, C., Saalmann, Y.B., Predictive coding as a model of sensory disconnection: relevance to anaesthetic mechanisms. Br J Anaesth 126 (2021), 37–40 The article proposes that predictive coding is a valuable framework for understanding sensory disconnection during anesthesia. The authors argue that anesthetics may disrupt specific components of predictive coding — particularly feedforward prediction error propagation and estimates of precision — leading to a mismatch between actual sensory input and higher-order cortical predictions.
Kanai, R., Komura, Y., Shipp, S., Friston, K., Cerebral hierarchies: predictive processing, precision and the pulvinar. Philos Trans R Soc B Biol Sci, 370, 2015, 20140169.
Andrillon, T., Kouider, S., The vigilant sleeper: neural mechanisms of sensory (de)coupling during sleep. Curr Opin Physiol 15 (2020), 47–59 This article reviews the mechanisms of sensory disconnection during sleep, exploring how the brain reduces responsiveness to external stimuli while maintaining some level of environmental monitoring. It challenges the traditional thalamic gating hypothesis by presenting evidence that sensory information can still reach and be processed by the cortex during sleep. The authors propose alternative mechanisms — such as cortical gating during NREM sleep and maximal absorption or inattentiveness during REM sleep — that help balance the need to protect sleep with the ability to detect important external cues.
Esser, S.K., Hill, S., Tononi, G., Breakdown of effective connectivity during slow wave sleep: investigating the mechanism underlying a cortical gate using large-scale modeling. J Neurophysiol 102 (2009), 2096–2111.
Massimini, M., Ferrarelli, F., Huber, R., Esser, S.K., Singh, H., Tononi, G., Breakdown of cortical effective connectivity during sleep. Science 309 (2005), 2228–2232.
Funk, C.M., Honjoh, S., Rodriguez, A.V., Cirelli, C., Tononi, G., Local slow waves in superficial layers of primary cortical areas during REM sleep. Curr Biol 26 (2016), 396–403.
Baird, B., Castelnovo, A., Riedner, B.A., Lutz, A., Ferrarelli, F., Boly, M., Davidson, R.J., Tononi, G., Human rapid eye movement sleep shows local increases in low-frequency oscillations and global decreases in high-frequency oscillations compared to resting wakefulness. eNeuro 5 (2018), 293–311.
Mhuircheartaigh, R.N., Warnaby, C., Rogers, R., Jbabdi, S., Tracey, I., Slow-wave activity saturation and thalamocortical isolation during propofol anesthesia in humans. Sci Transl Med, 5, 2013, 208ra148.
Moheimanian, L., Paraskevopoulou, S.E., Adamek, M., Schalk, G., Brunner, P., Modulation in cortical excitability disrupts information transfer in perceptual-level stimulus processing. Neuroimage, 243, 2021, 118498.
Jensen, O., Mazaheri, A., Shaping functional architecture by oscillatory alpha activity: gating by inhibition. Front Hum Neurosci, 4, 2010, 186.
de Pesters, A., Coon, W.G., Brunner, P., Gunduz, A., Ritaccio, A.L., Brunet, N.M., de Weerd, P., Roberts, M.J., Oostenveld, R., Fries, P., et al. Alpha power indexes task-related networks on large and small scales: a multimodal ECoG study in humans and a non-human primate. Neuroimage 134 (2016), 122–131.
Lange, J., Oostenveld, R., Fries, P., Reduced occipital alpha power indexes enhanced excitability rather than improved visual perception. J Neurosci 33 (2013), 3212–3220.
Klimesch, W., Sauseng, P., Hanslmayr, S., EEG alpha oscillations: the inhibition-timing hypothesis. Brain Res Rev 53 (2007), 63–88.
Mazaheri, A., Jensen, O., Rhythmic pulsing: linking ongoing brain activity with evoked responses. Front Hum Neurosci, 4, 2010, 177.
Darracq, M., Funk, C.M., Polyakov, D., Riedner, B., Gosseries, O., Nieminen, J.O., Bonhomme, V., Brichant, J.F., Boly, M., Laureys, S., et al. Evoked alpha power is reduced in disconnected consciousness during sleep and anesthesia. Sci Rep 8 (2018), 1–10.
Hansen, J.Y., Shafiei, G., Markello, R.D., Smart, K., Cox, S.M.L., Nørgaard, M., Beliveau, V., Wu, Y., Gallezot, J.D., Aumont, É., et al. Mapping neurotransmitter systems to the structural and functional organization of the human neocortex. Nat Neurosci 25 (2022), 1569–1581.
