Integrated information structure collapses with anesthetic loss of conscious arousal in<i>Drosophila melanogaster</i>

Leung, Angus; Cohen, Dror; Swinderen, Bruno van; Tsuchiya, Naotsugu

doi:10.1101/2020.05.17.090001

Cited by 6 publications

(7 citation statements)

References 89 publications

(139 reference statements)

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“…However, as argued by Feldman and Crutchfield [73], there are fundamental limitations to how much insight can be gained by even a "well-behaved" scalar measure of complexity. This notion was recently given empirical support by the finding that, when attempting to discriminate between conscious and anesthetized states, highdimensional information structures did a significantly better job than standard scalar measures [74].…”

Section: Discussionmentioning

confidence: 98%

Topological Analysis of Differential Effects of Ketamine and Propofol Anesthesia on Brain Dynamics

Varley

Denny

Sporns

et al. 2020

Preprint

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Research into the neural correlates of consciousness has found that the vividness and complexity of conscious experience is related to the structure of brain dynamics, and that alterations to consciousness track changes in temporal evolution of brain states. Despite inducing externally similar states, propofol and ketamine produce different subjective states of consciousness. Here we explore the different effects of these two anaesthetics on the structure of dynamical attractors reconstructed from brain activity recorded electrophysiologically from cerebral cortex of a non-human primate. We used two different methods of attractor reconstruction. The first embeds the recordings in a continuous high-dimensional manifold on which we use topological data analysis to infer the presence (or absence) of higher-order dynamics. The second reconstruction, an ordinal partition network embedding, allows us to create a discrete state-transition network approximation of a continuous attractor, which is amenable to information-theoretic analysis and contains rich information about state-transition dynamics. We find significant differences between the awake, ketamine, and propofol conditions. Propofol significantly decreased the expression of higher-order structure in brain dynamics, while ketamine had the opposite effect, promoting an increase in complex dynamic features. Overall we found that ketamine produced dynamics similar to normal waking consciousness while propofol did not, and the significance of these findings is discussed. different drugs with a specific focus on how different dynamics might relate to conscious awareness [55,63]. In this paper, we take such a comparative approach to explore the differences between the effects of propofol and ketamine on multi-scale brain dynamics with an eye specifically to how these dynamics might explain the differences in consciousness induced by both drugs. Here we characterize brain dynamics by adapting two complementary models capturing the evolution of whole-brain states through time: the first plots a trajectory through a high-dimensional configuration space, while the other discretizes transitions into a Markovian state-transition network.While ketamine and propofol are both classified broadly as anesthetics, and both obliterate consciousness at high doses, it is useful to compare their different pharmacologies and the differences between the states they induce at low-to-moderate doses. By binding to GABA A receptors, propofol triggers widespread inhibition of neuronal activity and even at low doses, induces states of amnesia, sedation, atonia, and at higher doses, full anesthesia [29,23]. In contrast, ketamine acts primarily as an antagonist of glutamaterigic NMDA receptors [29,66], causing widespread, light central nervous system stimulation and a state typically referred to as "dissociative anesthesia" [16,33]. Unlike propofol, which simply ablates consciousness, an otherwise unresponsive patient anesthetized with ketamine often continues to have complex, conscious experi...

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Section: Discussionmentioning

confidence: 98%

Topological Analysis of Differential Effects of Ketamine and Propofol Anesthesia on Brain Dynamics

Varley

Denny

Sporns

et al. 2020

Preprint

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“…A particularly promising analytical approach in this regard is provided by the Integrated Information Theory (IIT) of consciousness proposed by Tononi (Tononi, 2004). Recent advances of IIT have culminated in the development of algorithms to empirically derive (accurate proxies of) informational structures from neural recordings (Barrett & Seth, 2011;Leung, Cohen, Van Swinderen, & Tsuchiya, 2020;Mayner et al, 2018;Oizumi, Albantakis, & Tononi, 2014;Oizumi, Amari, Yanagawa, Fujii, & Tsuchiya, 2016;Tegmark, 2016).…”

Section: Outlook 2: Developments Towards An Empirically-testable Quanmentioning

confidence: 99%

Growing evidence for separate neural mechanisms for attention and consciousness

Maier

Tsuchiya

2020

Atten Percept Psychophys

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Our conscious experience of the world seems to go in lockstep with our attentional focus: we tend to see, hear, taste and feel what we attend to, and vice versa. This tight coupling between attention and consciousness has given rise to the idea that these two phenomena are indivisible. In the late 1950s, the honoree of this special issue, Charles Eriksen, was among a small group of early pioneers that sought to investigate whether a transient increase in overall level of attention (alertness) in response to a noxious stimulus can be decoupled from conscious perception using experimental techniques. Recent years saw a similar debate regarding whether attention and consciousness are two dissociable processes. Initial evidence that attention and consciousness are two separate processes primarily rested on behavioral data. However, the past couple of years witnessed an explosion of studies aimed at testing this conjecture using neuroscientific techniques. Here we provide an overview of these and related empirical studies on the distinction between the neuronal correlates of attention and consciousness, and detail how advancements in theory and technology can bring about a more detailed understanding of the two. We argue that the most promising approach will combine ever evolving neurophysiological and interventionist tools with quantitative, empirically testable theories of consciousness that are grounded in a mathematically formalized understanding of phenomenology.

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“…Measures that aim to capture more directly the fundamental properties captured by PCI (i.e. information differentiation and integration) have also shown promise in separating various states in humans (Farnes et al, 2020;Kim et al, 2018;Kim & Lee, 2019;Schartner et al, 2015;Schartner et al, 2017) and animals (Abásolo et al, 2015;Afrasiabi et al, 2021;Hudetz et al, 2015;Leung et al, 2021). However, such measures have yet to be compared directly with PCI in rodents using multiple anesthetic agents.…”

Section: Introductionmentioning

confidence: 99%

Effect of anesthesia in rats on measures of complexity, differentiation, and integrated information

Nilsen¹,

Arena²,

Storm³

2023

Preprint

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To investigate proposed mechanisms behind loss of consciousness, it is important to extend the current state of the field in human research to rodents. Perturbational complexity index (PCI) is a promising metric of “capacity for consciousness” in humans. PCI is based on a perturbational approach that allows inferring a system’s capacity for causal integration and differentiation of information. However, PCI is technically demanding and time-consuming. Thus, measures based on spontaneous EEG recordings may be more practical for certain clinical purposes. Furthermore, while a perturbational approach might better assess a system’s capacity for information processing, analysis of spontaneous EEG might be more indicative of current ongoing dynamics. Here, we compare PCI to a range of spontaneous EEG-based measures of signal diversity and integrated information in rats undergoing propofol, sevoflurane, and ketamine anesthesia.We find that Lempel-Ziv complexity, amplitude coalition entropy, and geometric integrated information are able to distinguish between awake and anesthesia, and that all implemented measures (except synchrony coalition entropy) were rank-order correlated with PCI. In addition, while the measures of signal diversity decreased in anesthesia (except for ketamine), several measures of integrated information increased, contrary to expectations. Based on a divergence in network properties estimated from directed functional connectivity (current results) and effective connectivity (earlier results), we speculate that while anesthesia may disrupt global cortico-cortical information transfer, as suggested by perturbation-based approaches, spontaneous activity may appear to suggest the opposite because of driving subcortical projections from e.g. the thalamus, or suppressed encoding specificity of information.

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Integrated information structure collapses with anesthetic loss of conscious arousal inDrosophila melanogaster

Cited by 6 publications

References 89 publications

Topological Analysis of Differential Effects of Ketamine and Propofol Anesthesia on Brain Dynamics

Topological Analysis of Differential Effects of Ketamine and Propofol Anesthesia on Brain Dynamics

Growing evidence for separate neural mechanisms for attention and consciousness

Effect of anesthesia in rats on measures of complexity, differentiation, and integrated information

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