scholarly journals Criticality Creates a Functional Platform for Network Transitions between Internal and External Processing Modes in the Human Brain

2020 ◽  
Author(s):  
Minkyung Kim ◽  
Hyoungkyu Kim ◽  
Zirui Huang ◽  
George A. Mashour ◽  
Denis Jordan ◽  
...  
Keyword(s):  
Brain Network ◽  
External Information ◽  
Altered States ◽  
Order And Disorder ◽  
States Of Consciousness ◽  
Processing Modes ◽  
Internal Information ◽  
External Stimuli ◽  
The Brain ◽  
Temporal Windows

AbstractContinuous switching between internal and external modes in the brain is a key process of constructing inner models of the outside world. However, how the brain continuously switches between two modes remains elusive. Here, we propose that a large synchronization fluctuation of the brain network emerging only near criticality (i.e., a balanced state between order and disorder) spontaneously creates temporal windows with distinct preferences for integrating internal information of the network and external stimuli. Using a computational model and empirical data analysis during alterations of consciousness in human, we present that synchronized and incoherent networks respectively bias toward internal and external information with specific network configurations. The network preferences are the most prominent in conscious states; however, they disrupt in altered states of consciousness. We suggest that criticality produces a functional platform of the brain’s capability for continuous switching between two modes, which is crucial for the emergence of consciousness.

scholarly journals Criticality Creates a Functional Platform for Network Transitions Between Internal and External Processing Modes in the Human Brain

2021 ◽  
Vol 15 ◽  
Author(s):  
Minkyung Kim ◽  
Hyoungkyu Kim ◽  
Zirui Huang ◽  
George A. Mashour ◽  
Denis Jordan ◽  
...  
Keyword(s):  
Information Integration ◽  
Brain Network ◽  
External Information ◽  
Order And Disorder ◽  
Processing Modes ◽  
Internal Information ◽  
Fmri Analysis ◽  
Minimally Conscious ◽  
External Stimuli ◽  
The Brain

Continuous switching between internal and external modes in the brain appears important for generating models of the self and the world. However, how the brain transitions between these two modes remains unknown. We propose that a large synchronization fluctuation of brain networks, emerging only near criticality (i.e., a balanced state between order and disorder), spontaneously creates temporal windows with distinct preferences for integrating the network’s internal information or for processing external stimuli. Using a computational model, electroencephalography (EEG) analysis, and functional magnetic resonance imaging (fMRI) analysis during alterations of consciousness in humans, we report that synchronized and incoherent networks, respectively, bias toward internal and external information with specific network configurations. In the brain network model and EEG-based network, the network preferences are the most prominent at criticality and in conscious states associated with the bandwidth 4−12 Hz, with alternating functional network configurations. However, these network configurations are selectively disrupted in different states of consciousness such as general anesthesia, psychedelic states, minimally conscious states, and unresponsive wakefulness syndrome. The network preference for internal information integration is only significant in conscious states and psychedelic states, but not in other unconscious states, suggesting the importance of internal information integration in maintaining consciousness. The fMRI co-activation pattern analysis shows that functional networks that are sensitive to external stimuli–such as default mode, dorsal attentional, and frontoparietal networks–are activated in incoherent states, while insensitive networks, such as global activation and deactivation networks, are dominated in highly synchronized states. We suggest that criticality produces a functional platform for the brain’s capability for continuous switching between two modes, which is crucial for the emergence of consciousness.

scholarly journals Differential effects of propofol and ketamine on critical brain dynamics

2020 ◽  
Vol 16 (12) ◽  
pp. e1008418
Author(s):  
Thomas F. Varley ◽  
Olaf Sporns ◽  
Aina Puce ◽  
John Beggs
Keyword(s):  
Cellular Level ◽  
Brain Dynamics ◽  
Neuronal Cultures ◽  
Altered States ◽  
Differential Effects ◽  
States Of Consciousness ◽  
Anaesthetized Rats ◽  
And Control ◽  
The Brain

Whether the brain operates at a critical “tipping” point is a long standing scientific question, with evidence from both cellular and systems-scale studies suggesting that the brain does sit in, or near, a critical regime. Neuroimaging studies of humans in altered states of consciousness have prompted the suggestion that maintenance of critical dynamics is necessary for the emergence of consciousness and complex cognition, and that reduced or disorganized consciousness may be associated with deviations from criticality. Unfortunately, many of the cellular-level studies reporting signs of criticality were performed in non-conscious systems (in vitro neuronal cultures) or unconscious animals (e.g. anaesthetized rats). Here we attempted to address this knowledge gap by exploring critical brain dynamics in invasive ECoG recordings from multiple sessions with a single macaque as the animal transitioned from consciousness to unconsciousness under different anaesthetics (ketamine and propofol). We use a previously-validated test of criticality: avalanche dynamics to assess the differences in brain dynamics between normal consciousness and both drug-states. Propofol and ketamine were selected due to their differential effects on consciousness (ketamine, but not propofol, is known to induce an unusual state known as “dissociative anaesthesia”). Our analyses indicate that propofol dramatically restricted the size and duration of avalanches, while ketamine allowed for more awake-like dynamics to persist. In addition, propofol, but not ketamine, triggered a large reduction in the complexity of brain dynamics. All states, however, showed some signs of persistent criticality when testing for exponent relations and universal shape-collapse. Further, maintenance of critical brain dynamics may be important for regulation and control of conscious awareness.

Perspectives on the Field of Cognitive Informatics and its Future Development

2012 ◽  
pp. 20-34
Author(s):  
Yingxu Wang ◽  
Bernard Carlos Widrow ◽  
Bo Zhang ◽  
Witold Kinsner ◽  
Kenji Sugawara ◽  
...  
Keyword(s):  
Information Processing ◽  
Computer Science ◽  
Future Development ◽  
External Information ◽  
Cognitive Computing ◽  
Cognitive Informatics ◽  
Internal Information ◽  
Processing Mechanisms ◽  
The Brain ◽  
Science Information

The contemporary wonder of sciences and engineering has recently refocused on the beginning point of: how the brain processes internal and external information autonomously and cognitively rather than imperatively like conventional computers. Cognitive Informatics (CI) is a transdisciplinary enquiry of computer science, information sciences, cognitive science, and intelligence science that investigates the internal information processing mechanisms and processes of the brain and natural intelligence, as well as their engineering applications in cognitive computing. This paper reports a set of eight position statements presented in the plenary panel of IEEE ICCI’10 on Cognitive Informatics and Its Future Development contributed from invited panelists who are part of the world’s renowned researchers and scholars in the field of cognitive informatics and cognitive computing.

Altered states of consciousness in epilepsy: a DTI study of the brain

2016 ◽  
Vol 127 (8) ◽  
pp. 667-672 ◽  
Author(s):  
Fangfang Xie ◽  
Wu Xing ◽  
Xiaoyi Wang ◽  
Weihua Liao ◽  
Wei Shi
Keyword(s):  
Altered States Of Consciousness ◽  
Altered States ◽  
States Of Consciousness ◽  
The Brain

scholarly journals EEG microstate dynamics indicate a U-shaped path to propofol-induced loss of consciousness

2021 ◽  
Author(s):  
Fiorenzo Artoni ◽  
Julien Maillard ◽  
Juliane Britz ◽  
Martin Seeber ◽  
Christopher Lysakowski ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Brain Activity ◽  
Altered States Of Consciousness ◽  
Initial Increase ◽  
Altered States ◽  
Stream Of Consciousness ◽  
Sequence Complexity ◽  
States Of Consciousness ◽  
Brain States ◽  
The Brain

It is commonly believed that the stream of consciousness is not continuous but parsed into transient brain states manifesting themselves as discrete spatiotemporal patterns of global neuronal activity. Electroencephalographical (EEG) microstates are proposed as the neurophysiological correlates of these transiently stable brain states that last for fractions of seconds. To further understand the link between EEG microstate dynamics and consciousness, we continuously recorded high-density EEG in 23 surgical patients from their awake state to unconsciousness, induced by step-wise increasing concentrations of the intravenous anesthetic propofol. Besides the conventional parameters of microstate dynamics, we introduce a new method that estimates the complexity of microstate sequences. The brain activity under the surgical anesthesia showed a decreased sequence complexity of the stereotypical microstates, which became sparser and longer-lasting. However, we observed an initial increase in microstates' temporal dynamics and complexity with increasing depth of sedation leading to a distinctive U-shape that may be linked to the paradoxical excitation induced by moderate levels of propofol. Our results support the idea that the brain is in a metastable state under normal conditions, balancing between order and chaos in order to flexibly switch from one state to another. The temporal dynamics of EEG microstates indicate changes of this critical balance between stability and transition that lead to altered states of consciousness.

scholarly journals A higher-order theory of emotional consciousness

2017 ◽  
Vol 114 (10) ◽  
pp. E2016-E2025 ◽  
Author(s):  
Joseph E. LeDoux ◽  
Richard Brown
Keyword(s):  
Order Theory ◽  
Higher Order ◽  
Emotional States ◽  
Emotional Experiences ◽  
Neural Signals ◽  
Cognitive States ◽  
States Of Consciousness ◽  
Higher Order Theory ◽  
External Stimuli ◽  
The Brain

Emotional states of consciousness, or what are typically called emotional feelings, are traditionally viewed as being innately programmed in subcortical areas of the brain, and are often treated as different from cognitive states of consciousness, such as those related to the perception of external stimuli. We argue that conscious experiences, regardless of their content, arise from one system in the brain. In this view, what differs in emotional and nonemotional states are the kinds of inputs that are processed by a general cortical network of cognition, a network essential for conscious experiences. Although subcortical circuits are not directly responsible for conscious feelings, they provide nonconscious inputs that coalesce with other kinds of neural signals in the cognitive assembly of conscious emotional experiences. In building the case for this proposal, we defend a modified version of what is known as the higher-order theory of consciousness.

scholarly journals Neural dynamics of stroboscopic stimulation at different stimulation frequencies

2021 ◽  
Author(s):  
Ram Kumar Pari
Keyword(s):  
Spectral Power ◽  
Neural Dynamics ◽  
Systematic Research ◽  
Driving Frequency ◽  
Altered States ◽  
States Of Consciousness ◽  
Signal Diversity ◽  
Experiential Content ◽  
Specific Stimulation ◽  
The Brain

Stroboscopic stimulation has been previously shown to induce visual hallucinations and altered states of consciousness, state by entraining the brain to the driving frequency, similar to those reported during the psychedelics although little systematic research exists on the effect of specific stimulation frequency on experience. The present study investigated the effects of different stroboscopic stimulation frequencies on neural dynamics, such as signal diversity (Lempel-Ziv complexity) and spectral power and attempted to relate these changes to self-reported changes in experiential content. The results indicated that the stimulation frequencies near the alpha band (8 to 12 Hz) caused the greatest increase across all neural measures, with 8 Hz consistently displaying the most pronounced results, relative to baseline. All tested frequencies led to an increase in all experiential dimensions, relative to baseline.

Consciousness: A Very Short Introduction

2017 ◽  
Author(s):  
Susan Blackmore
Keyword(s):  
Neural Correlates ◽  
Altered States Of Consciousness ◽  
Altered States ◽  
Short Introduction ◽  
New Developments ◽  
Brain Science ◽  
States Of Consciousness ◽  
The World ◽  
Construction Of Self ◽  
The Brain

Consciousness is ‘the last great mystery for science’. How can a physical brain create our experience of the world? What creates our identity? Do we really have free will? Could consciousness itself be an illusion? Exciting new developments in brain science are continuing these debates, and the field has now expanded to include biologists, neuroscientists, psychologists, and philosophers. Consciousness: A Very Short Introduction clarifies the potentially confusing arguments, and the major theories, whilst also outlining the amazing pace of neuroscience discoveries. Covering areas such as construction of self in the brain, mechanisms of attention, neural correlates of consciousness, and physiology of altered states of consciousness, it highlights the latest findings.

Perspectives on the Field of Cognitive Informatics and its Future Development

2011 ◽  
Vol 5 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Yingxu Wang ◽  
Bernard Carlos Widrow ◽  
Bo Zhang ◽  
Witold Kinsner ◽  
Kenji Sugawara ◽  
...  
Keyword(s):  
Information Processing ◽  
Future Development ◽  
External Information ◽  
Cognitive Computing ◽  
Cognitive Informatics ◽  
Internal Information ◽  
Processing Mechanisms ◽  
The Brain ◽  
Science Information ◽  
Intelligence Science

The contemporary wonder of sciences and engineering has recently refocused on the beginning point of: how the brain processes internal and external information autonomously and cognitively rather than imperatively like conventional computers. Cognitive Informatics (CI) is a transdisciplinary enquiry of computer science, information sciences, cognitive science, and intelligence science that investigates the internal information processing mechanisms and processes of the brain and natural intelligence, as well as their engineering applications in cognitive computing. This paper reports a set of eight position statements presented in the plenary panel of IEEE ICCI’10 on Cognitive Informatics and Its Future Development contributed from invited panelists who are part of the world’s renowned researchers and scholars in the field of cognitive informatics and cognitive computing.

The persistence of the subjective in neuropsychopharmacology: observations of contemporary hallucinogen research

2010 ◽  
Vol 23 (1) ◽  
pp. 37-57 ◽  
Author(s):  
Nicolas Langlitz
Keyword(s):  
Subjective Experience ◽  
Brain Research ◽  
Altered States ◽  
Way Of Life ◽  
Drug Induced ◽  
Scientific Publications ◽  
States Of Consciousness ◽  
Self Image ◽  
Epistemic Object ◽  
The Brain

The elimination of subjectivity through brain research and the replacement of so-called ‘folk psychology’ by a neuroscientifically enlightened worldview and self-conception has been both hoped for and feared. But this cultural revolution is still pending. Based on nine months of fieldwork on the revival of hallucinogen research since the ‘Decade of the Brain,’ this paper examines how subjective experience appears as epistemic object and practical problem in a psychopharmacological laboratory. In the quest for neural correlates of (drug-induced altered states of) consciousness, introspective accounts of test subjects play a crucial role in neuroimaging studies. Firsthand knowledge of the drugs’ flamboyant effects provides researchers with a personal knowledge not communicated in scientific publications, but key to the conduct of their experiments. In many cases, the ‘psychedelic experience’ draws scientists into the field and continues to inspire their self-image and way of life. By exploring these domains the paper points to a persistence of the subjective in contemporary neuropsychopharmacology.

Sign in / Sign up

Export Citation Format

Share Document