Abstract
The use of anaesthesia is a fundamental tool in the investigation of consciousness. Anesthesia procedures allow to investigate different states of consciousness from sedation to deep anesthesia within controlled scenarios. In this study we use information quantifiers to measure the complexity of electrocorticogram recordings in monkeys. We apply these metrics to compare different stages of general anesthesia for evaluating consciousness in several anesthesia protocols. We find that the complexity of brain activity can be used as a correlate of consciousness. For two of the anaesthetics used, propofol and medetomidine, we find that the anaesthetised state is accompanied by a reduction in the complexity of brain activity. On the other hand we observe that use of ketamine produces an increase in complexity measurements. We relate this observation with increase activity within certain brain regions associated with the ketamine used doses. Our measurements indicate that complexity of brain activity is a good indicator for a general evaluation of different levels of consciousness awareness, both in anesthetized and non anesthetizes states.
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Bademosi, A. T., Steeves, J., Karunanithi, S., Zalucki, O. H., Gormal, R. S., Liu, S., Lauwers, E., Verstreken, P., Anggono, V., Meunier, F. A. et al. (2018). Trapping of syntaxin1a in presynaptic nanoclusters by a clinically relevant general anesthetic. Cell Reports, 22, 427–440.
Bandt, C. (2017). A new kind of permutation entropy used to classify sleep stages from invisible EEG microstructure. Entropy, 19, 197.
Bandt, C., & Pompe, B. (2002). Permutation entropy: a natural complexity measure for time series. Physical review letters, 88, 174102.
Berger, H. (1929). Über das elektroenkephalogramm des menschen. Archiv für psychiatrie und nervenkrankheiten, 87, 527–570.
Bonhomme, V., Vanhaudenhuyse, A., Demertzi, A., Bruno, M.-A., Jaquet, O., Bahri, M., Plenevaux, A., Boly, M., Boveroux, P., Soddu, A. et al. (2016). Resting-state network-specific breakdown of functional connectivity during ketamine alteration of consciousness in volunteers. Anesthesiology, 125, 873–888.
Brake, N., Duc, F., Rokos, A., Arseneau, F., Shahiri, S., Khadra, A., & Plourde, G. (2021). Aperiodic eeg activity masks the dynamics of neural oscillations during loss of consciousness from propofol. bioRxiv.
Brown, E., Purdon, P. L., & Van Dort, C. J. (2011). General anesthesia and altered states of arousal: a systems neuroscience analysis. Annual review of neuroscience, 34, 601–628.
Bruhn, J., Röpcke, H., & Hoeft, A. (2000). Approximate entropy as an electroencephalographic measure of anesthetic drug effect during desflurane anesthesia. The Journal of the American Society of Anesthesiologists, 92, 715–726.
Carhart-Harris, R. L., & Friston, K. (2019). Rebus and the anarchic brain: toward a unified model of the brain action of psychedelics. Pharmacological reviews, 71, 316–344.
Carhart-Harris, R. L., Leech, R., Hellyer, P. J., Shanahan, M., F., A., Tagliazucchi, E., Chialvo, D. R., & Nutt, D. (2014). The entropic brain: a theory of conscious states informed by neuroimaging research with psychedelic drugs. Frontiers in human neuroscience, 8, 20.
Casali, A., Gosseries, O., Rosanova, M., Boly, M., Sarasso, S., Casali, K., Casarotto, S., Bruno, M., Laureys, S., Tononi, G. et al. (2013). A theoretically based index of consciousness independent of sensory processing and behavior. Science translational medicine, 5, 198ra105–198ra105.
Cascella, M., Bimonte, S., & Muzio, M. R. (2018). Towards a better understanding of anesthesia emergence mechanisms: Research and clinical implications. World journal of methodology, 8, 9.
Colombo, M., Napolitani, M., Boly, M., Gosseries, O., Casarotto, S., Rosanova, M., Brichant, J.-F., Boveroux, P., Rex, S., Laureys, S. et al. (2019). The spectral exponent of the resting eeg indexes the presence of consciousness during unresponsiveness induced by propofol, xenon, and ketamine. Neuroimage, 189, 631–644.
Cover, T. M., & Thomas, J. A. (2006). Elements of Information Theory. (2nd ed.). John Wiley & Sons.
Domino, E., Chodoff, P., & Corssen, G. (1965). Pharmacologic effects of ci-581, a new dissociative anesthetic, in man. Clinical Pharmacology & Therapeutics, 6, 279–291.
Ferenets, R., Vanluchene, A., Lipping, T., Heyse, B., & Struys, M. (2007). Behavior of entropy/complexity measures of the electroencephalogram during propofol-induced sedation: dose-dependent effects of remifentanil. The Journal of the American Society of Anesthesiologists, 106, 696–706.
Feshchenko, V., Veselis, R., & Reinsel, R. (2004). Propofol-induced alpha rhythm. Neuropsychobiology, 50, 257–266.
Fisher, R. A. (1922). On the mathematical foundations of theoretical statistics. Philosophical Transactions of the Royal Society of London. Series A, Containing Papers of a Mathematical or Physical Character, 222, 309–368.
Franks, N. (2006). Molecular targets underlying general anaesthesia. British journal of pharmacology, 147, S72–S81.
Frieden, B. R. (2004). Science from Fisher information: a unification. Cambridge University Press.
Grandjean, J., Schroeter, A., Batata, I., & Rudin, M. (2014). Optimization of anesthesia protocol for resting-state fmri in mice based on differential effects of anesthetics on functional connectivity patterns. Neuroimage, 102, 838–847.
Gugino, L., Chabot, R., Prichep, L., John, E., Formanek, V., & Aglio, L. (2001). Quantitative eeg changes associated with loss and return of consciousness in healthy adult volunteers anaesthetized with propofol or sevoflurane. British journal of anaesthesia, 87, 421–428.
Hahn, G., Zamora-López, G., Uhrig, L., Tagliazucchi, E., Laufs, H., Mantini, D., Kringelbach, M., Jarraya, B., & Deco, G. (2021). Signature of consciousness in brain-wide synchronization patterns of monkey and human fmri signals. NeuroImage, 226, 117470.
Hansson, M., Gansler, T., & Salomonsson, G. (1998). A system for tracking changes in the mid-latency evoked potential during anesthesia. IEEE transactions on biomedical engineering, 45, 323–334.
Hantal, G., Fábián, B., Sega, M., Jójárt, B., & Jedlovszky, P. (2019). Effect of general anesthetics on the properties of lipid membranes of various compositions. Biochimica et Biophysica Acta (BBA)-Biomembranes, 1861, 594–609.
Hemmings J., H. C., Riegelhaupt, P. M., Kelz, M. B., Solt, K., Eckenhoff, R. G., Orser, B. A., & Goldstein, P. A. (2019). Towards a comprehensive understanding of anesthetic mechanisms of action: a decade of discovery. Trends in pharmacological sciences, 40, 464–481.
Hong, L., Summerfelt, A., Buchanan, R., O’donnell, P., Thaker, G., Weiler, M., & Lahti, A. (2010). Gamma and delta neural oscillations and association with clinical symptoms under subanesthetic ketamine. Neuropsychopharmacology, 35, 632–640.
Hudetz, A. G., Liu, X., Pillay, S., Boly, M., & Tononi, G. (2016). Propofol anesthesia reduces lempel-ziv complexity of spontaneous brain activity in rats. Neuroscience letters, 628, 132–135.
Hunt, M., Raynaud, B., & Garcia, R. (2006). Ketamine dose-dependently induces high-frequency oscillations in the nucleus accumbens in freely moving rats. Biological psychiatry, 60, 1206–1214.
Ibáñez-Molina, A., Iglesias-Parro, S., Soriano, M., & Aznarte, J. (2015). Multiscale lempel-ziv complexity for eeg measures. Clinical Neurophysiology, 126, 541–548.
Jensen, E. W., Litvan, H., Struys, M., & Vazquez, P. M. (2004). Pitfalls and challenges when assessing the depth of hypnosis during general anaesthesia by clinical signs and electronic indices. Acta anaesthesiologica scandinavica, 48, 1260–1267.
Kaspar, F., & Schuster, H. G. (1987). Easily calculable measure for the complexity of spatiotemporal patterns. Physical Review A, 36, 842.
Keller, K., Mangold, T., Stolz, I., & Werner, J. (2017). Permutation entropy: New ideas and challenges. Entropy, 19, 134.
Khan, K. S., Hayes, I., & Buggy, D. J. (2014). Pharmacology of anaesthetic agents i: intravenous anaesthetic agents. Continuing Education in Anaesthesia, Critical Care & Pain, 14, 100–105.
Kim, H., Moon, J.-Y., Mashour, G. A., & Lee, U. (2018). Mechanisms of hysteresis in human brain networks during transitions of consciousness and unconsciousness: Theoretical principles and empirical evidence. PLoS computational biology, 14, e1006424.
Kitazono, J., Kanai, R., & Oizumi, M. (2018). Efficient algorithms for searching the minimum information partition in integrated information theory. Entropy, 20, 173.
Kocsis, B., Brown, R., McCarley, R., & Hajos, M. (2013). Impact of ketamine on neuronal network dynamics: Translational modeling of schizophrenia-relevant deficits. CNS Neuroscience & Therapeutics, 19, 437–447.
Krystal, J. H., Karper, L. P., Seibyl, J. P., Freeman, G. K., Delaney, R., Bremner, J. D., Heninger, G. R., Bowers, M. B., & Charney, D. S. (1994). Subanesthetic effects of the noncompetitive nmda antagonist, ketamine, in humans: psychotomimetic, perceptual, cognitive, and neuroendocrine responses. Archives of General Psychiatry, 51, 199–214.
Krzemiński, D., Kamiński, M., Marchewka, A., & Bola, M. (2017). Breakdown of long-range temporal correlations in brain oscillations during general anesthesia. Neuroimage, 159, 146–158.
Kuo, C., & Liang, S. (2011). Automatic stage scoring of single-channel sleep eeg based on multiscale permutation entropy. In 2011 IEEE Biomedical Circuits and Systems Conference (BioCAS) (pp. 448–451). IEEE.
Kushikata, T., & Hirota, K. (2014). Mechanisms of anesthetic emergence: evidence for active reanimation. Current Anesthesiology Reports, 4, 49–56.
Lazarewicz, M., Ehrlichman, R., Maxwell, C., Gandal, M., Finkel, L. H., & Siegel, S. (2010). Ketamine modulates theta and gamma oscillations. Journal of Cognitive Neuroscience, 22, 1452–1464.
Lempel, A., & Ziv, J. (1976). On the complexity of finite sequences. IEEE Transactions on Information Theory, 22, 75–81.
Lewis, L., Weiner, V., Mukamel, E., Donoghue, J., Eskandar, E., Madsen, J., Anderson, W., Hochberg, L., Cash, S., Brown, E. et al. (2012). Rapid fragmentation of neuronal networks at the onset of propofol-induced unconsciousness. Proceedings of the National Academy of Sciences, 109, E3377–E3386.
Li, D., Li, X., Liang, Z., Voss, L. J., & Sleigh, J. W. (2010). Multiscale permutation entropy analysis of eeg recordings during sevoflurane anesthesia. Journal of Neural Engineering, 7, 046010.
Li, X., Cui, S., & Voss, L. J. (2008). Using permutation entropy to measure the electroencephalographic effects of sevoflurane. The Journal of the American Society of Anesthesiologists, 109, 448–456.
Liang, Z., Wang, Y., Sun, X., Li, D., Voss, L. J., Sleigh, J. W., Hagihira, S., & Li, X. (2015). Eeg entropy measures in anesthesia. Frontiers in Computational Neuroscience, 9, 16.
Liu, Q., Ma, L., Fan, S.-Z., Abbod, M. F., & Shieh, J.-S. (2018). Sample entropy analysis for the estimating depth of anaesthesia through human eeg signal at different levels of unconsciousness during surgeries. PeerJ, 6, e4817.
Loomis, A. L., Harvey, E. N., & Hobart, G. A. (1937). Cerebral states during sleep, as studied by human brain potentials. Journal of Experimental Psychology, 21, 127.
Luppi, A. I., Craig, M., Pappas, I., Finoia, P., Williams, G., Allanson, J., Pickard, J., Owen, A., Naci, L., Menon, D. et al. (2019). Consciousness-specific dynamic interactions of brain integration and functional diversity. Nature Communications, 10, 1–12.
Mammone, N., & Morabito, F. C. (2011). Analysis of absence seizure eeg via permutation entropy spatio-temporal clustering. In The 2011 International Joint Conference on Neural Networks (pp. 1417–1422). IEEE.
Martin, M. T., Plastino, A., & Rosso, O. A. (2006). Generalized statistical complexity measures: Geometrical and analytical properties. Physica A: Statistical Mechanics and its Applications, 369, 439–462.
Mateos, D. M., Diaz, J. M., & Lamberti, P. W. (2014). Permutation entropy applied to the characterization of the clinical evolution of epileptic patients under pharmacologicaltreatment. Entropy, 16, 5668–5676.
Mateos, D. M., Gómez-Ramírez, J., & Rosso, O. A. (2021). Using time causal quantifiers to characterize sleep stages. Chaos, Solitons & Fractals, 146, 110798.
Mateos, D. M., Guevara Erra, R., Wennberg, R., & Perez Velazquez, J. L. (2018). Measures of entropy and complexity in altered states of consciousness. Cognitive Neurodynamics, 12, 73–84.
Mateos, D. M., Wennberg, R., Guevara Erra, R., & Perez Velazquez, J. L. (2017). Consciousness as a global property of brain dynamic activity. Physical Review E, 96, 062410.
Mateos, D. M., Zozor, S., & Olivares, F. (2020). Contrasting stochasticity with chaos in a permutation lempel-ziv complexity–shannon entropy plane. Physica A: Statistical Mechanics and its Applications, 554, 124640.
Mukamel, E., Wong, K., Prerau, M., Brown, E., & Purdon, P. (2011). Phase-based measures of cross-frequency coupling in brain electrical dynamics under general anesthesia. In 2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society (pp. 1981–1984). IEEE.
Mukamel, E. A., Pirondini, E., Babadi, B., Wong, K. K., Pierce, E., Harrell, P., Walsh, J., Salazar-Gomez, A., Cash, S., Eskandar, E. et al. (2014). A transition in brain state during propofol-induced unconsciousness. Journal of Neuroscience, 34, 839–845.
Murphy, M., Bruno, M.-A., Riedner, B., Boveroux, P., Noirhomme, Q., Landsness, E., Brichant, J.-F., Phillips, C., Massimini, M., Laureys, S. et al. (2011). Propofol anesthesia and sleep: a high-density eeg study. Sleep, 34, 283–291.
Muthukumaraswamy, S., Shaw, A., Jackson, L., Hall, J., Moran, R., & Saxena, N. (2015). Evidence that subanesthetic doses of ketamine cause sustained disruptions of nmda and ampa-mediated frontoparietal connectivity in humans. Journal of Neuroscience, 35, 11694–11706.
Nasrallah, F., Lew, S., Low, A.S.-M., & Chuang, K.-H. (2014). Neural correlate of resting-state functional connectivity under a2 adrenergic receptor agonist, medetomidine. Neuroimage, 84, 27–34.
Nasrallah, F., Tan, J., & Chuang, K.-H. (2012). Pharmacological modulation of functional connectivity: a2-adrenergic receptor agonist alters synchrony but not neural activation. Neuroimage, 60, 436–446.
Nicol, A., & Morton, A. (2020). Characteristic patterns of eeg oscillations in sheep (ovis aries) induced by ketamine may explain the psychotropic effects seen in humans. Scientific reports, 10, 1–10.
Nicolaou, N., & Georgiou, J. (2011). The use of permutation entropy to characterize sleep electroencephalograms. Clinical EEG and Neuroscience, 42, 24–28.
Oizumi, M., Amari, S., Yanagawa, T., Fujii, N., & Tsuchiya, N. (2016). Measuring integrated information from the decoding perspective. PLoS Computational Biology, 12, e1004654.
Pennini, F., & Plastino, A. (2005). Reciprocity relations between ordinary temperature and the Frieden-Soffer Fisher temperature. Physical Review E, 71, 47102.
Purdon, P., Pierce, E., Mukamel, E., Prerau, M., Walsh, J., Wong, K., Salazar-Gomez, A., Harrell, P., Sampson, A. L., Cimenser, A. et al. (2013). Electroencephalogram signatures of loss and recovery of consciousness from propofol. Proceedings of the National Academy of Sciences, 110, E1142–E1151.
Quintero-Quiroz, C., Montesano, A. J., L.and Pons, Torrent, M. C., García-Ojalvo, J., & Masoller, C. (2018). Differentiating resting brain states using ordinal symbolic analysis. Chaos: An Interdisciplinary Journal of Nonlinear Science, 28, 106307.
Rivolta, D., Sauer, A. H. T., & et al. (2012). Effect of ketamine on gamma-band oscillation in MEG-data a comparison with schizofrenia. In Society of neuroscience, Abstrac (p. 38).
Rosso, O. A., Larrondo, H. A., Martin, M. T., Plastino, A., & Fuentes, M. A. (2007). Distinguishing noise from chaos. Physical Review Letters, 99, 154102.
Saba, W., Goutal, S., Kuhnast, B., Dollé, F., Auvity, S., Fontyn, Y., Cayla, J., Peyronneau, M.-A., Valette, H., & Tournier, N. (2015). Differential influence of propofol and isoflurane anesthesia in a non-human primate on the brain kinetics and binding of [18f]DPA-714, a positron emission tomography imaging marker of glial activation. European Journal of Neuroscience, 42, 1738–1745.
Sánchez-Moreno, P., Yánez, R., & Dehesa, J. (2009). Discrete densities and Fisher information. In Proceedings of the 14th International Conference on Difference Equations and Applications. Difference Equations and Applications. Istanbul, Turkey: Bahçesehir University Press (pp. 291–298).
Sarasso, S., Boly, M., Napolitani, M., Gosseries, O., Charland-Verville, V., Casarotto, S., Rosanova, M., Casali, A. G., Brichant, J., Boveroux, P. et al. (2015). Consciousness and complexity during unresponsiveness induced by propofol, xenon, and ketamine. Current Biology, 25, 3099–3105.
Sarasso, S., Casali, A. G., Casarotto, S., Rosanova, M., Sinigaglia, C., & Massimini, M. (2021). Consciousness and complexity: A consilience of evidence. Neuroscience of Consciousness, 7, 1–24.
Schartner, M., Seth, A., Noirhomme, Q., Boly, M., Bruno, M., Laureys, S., & Barrett, A. (2015). Complexity of multi-dimensional spontaneous eeg decreases during propofol induced general anaesthesia. PLoS One, 10, e0133532.
Schartner, M. M., Carhart-Harris, R. L., Barrett, A. B., Seth, A. K., & Muthukumaraswamy, S. D. (2017). Increased spontaneous meg signal diversity for psychoactive doses of ketamine, lsd and psilocybin. Scientific Reports, 7, 1–12.
Scheidegger, M., Walter, M., Lehmann, M., Metzger, C., Grimm, S., Boeker, H., Boesiger, P., Henning, A., & Seifritz, E. (2012). Ketamine decreases resting state functional network connectivity in healthy subjects: implications for antidepressant drug action.
Senior, C., Russell, T., Gazzaniga, M. S., & Raessens, J. (2006). Methods in mind. MIT press.
Shannon, C. E., & Weaver, W. (1998). The mathematical theory of communication. University of Illinois press.
Shaw, A., Saxena, N., Jackson, L., Hall, J., Singh, K., & Muthukumaraswamy, S. (2015). Ketamine amplifies induced gamma frequency oscillations in the human cerebral cortex. European Neuropsychopharmacology, 25, 1136–1146.
Shumbayawonda, E., Tosun, P. D., Fernández, A., Hughes, M. P., & Abásolo, D. (2018). Complexity changes in brain activity in healthy ageing: A permutation lempel-ziv complexity study of magnetoencephalograms. Entropy, 20, 506.
Soriano, M. C., Zunino, L., Rosso, O. A., Fischer, I., & Mirasso, C. R. (2011). Time scales of a chaotic semiconductor laser with optical feedback under the lens of a permutation information analysis. IEEE Journal of Quantum Electronics, 47, 252–261.
Todd, M. M. (1998). EEGs, EEG processing, and the bispectral index. The Journal of the American Society of Anesthesiologists, 89, 815–817.
Toker, D., Pappas, I., Lendner, J., Frohlich, J., Mateos, D., Muthukumaraswamy, S., Carhart-Harris, R., Paff, M., Vespa, P., Monti, M. et al. (2021). Consciousness is supported by near-critical cortical electrodynamics. bioRxiv.
Tononi, G., & Edelman, G. (1998). Consciousness and complexity. Science, 282, 1846–1851.
Varley, T., Denny, V., Sporns, O., & Patania, A. (2020). Topological analysis of differential effects of ketamine and propofol anaesthesia on brain dynamics. Royal Society Open Science, 8, 201971.
Varnäs, K., Finnema, S., Johnström, P., Arakawa, R., Halldin, C., Eriksson, L., & Farde, L. (2021). Effects of sevoflurane anaesthesia on radioligand binding to monoamine oxidase-b in vivo. British Journal of Anaesthesia, 126, 238–244.
Xu, J., Zheng, C., Jing, G., & Lu, D. (2004). Monitoring depth of anesthesia based on complexity of electroencephalogram. In IEEE International Workshop on Biomedical Circuits and Systems, 2004. (pp. S2–5). IEEE.
Yanagawa, T., Chao, Z., Hasegawa, N., & Fujii, N. (2013a). Large-scale information flow in conscious and unconscious states: an ecog study in monkeys. PLoS One, 8, e80845.
Yanagawa, T., Chao, Z., Hasegawa, N., & Fujii, N. (2013b). Large-scale information flow in conscious and unconscious states: an ecog study in monkeys. PLoS One, 8, e80845.
Zanin, M., Zunino, L., Rosso, O. A., & Papo, D. (2012). Permutation entropy and its main biomedical and econophysics applications: a review. Entropy, 14, 1553–1577.
Zanos, P., Moaddel, R., Morris, P. J., Riggs, L. M., Highland, J. N., Georgiou, P., Pereira, E., Albuquerque, E. X., Thomas, C. J., Zarate, C. A. et al. (2018). Ketamine and ketamine metabolite pharmacology: insights into therapeutic mechanisms. Pharmacological reviews, 70, 621–660.
Zhang, X.-S., Roy, R. J., & Jensen, E. W. (2001). Eeg complexity as a measure of depth of anesthesia for patients. IEEE transactions on biomedical engineering, 48, 1424–1433.
Zozor, S., Mateos, D. M., & Lamberti, P. W. (2014). Mixing Bandt-Pompe and Lempel-Ziv approaches: another way to analyze the complexity of continuous-state sequences. The European Physical Journal B, 87, 107.
Zunino, L., Soriano, M. C., Fischer, I., Rosso, O. A., & Mirasso, C. R. (2010). Permutation-information-theory approach to unveil delay dynamics from time-series analysis. Physical Review E, 82, 46212.
Zunino, L., Soriano, M. C., & Rosso, O. A. (2012). Distinguishing chaotic and stochastic dynamics from time series by using a multiscale symbolic approach. Physical Review E, 86, 46210.
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Fuentes, N., Garcia, A., Guevara, R. et al. Complexity of Brain Dynamics as a Correlate of Consciousness in Anaesthetized Monkeys. Neuroinform 20, 1041–1054 (2022). https://doi.org/10.1007/s12021-022-09586-3
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DOI: https://doi.org/10.1007/s12021-022-09586-3