scholarly journals Oscillatory Components of Psychedelic Experience

2021 ◽  
pp. 002216782110418
Author(s):  
Paul Grof
Keyword(s):  
Imaging Techniques ◽  
Brain Activity ◽  
Dynamic Aspect ◽  
Normal Range ◽  
States Of Consciousness ◽  
Psychedelic Drug ◽  
Experiential Content ◽  
Transformative Process ◽  
Oscillatory Brain Activity ◽  
The Brain

As humanity has been utilizing psychedelic substances for millennia, much knowledge has already been accumulated about the exploratory potential and therapeutic power of the psychedelic-induced nonordinary states of consciousness (NSC). However, we still have only a limited understanding of the process that unfolds in mind and the brain. Only recently have systematic investigations become possible, as the myths about psychedelics are abating and the legal strictures gradually loosening. With the availability of brain imaging techniques, exciting findings have been made about the associated dynamic brain processes. Our prospective observations of spontaneously generated NSC, major mood disorders, have been elucidating another dynamic aspect, the oscillatory brain processes. The findings indicate that the NSC’s propensity is markedly increased at the peaks of the oscillatory brain activity and that the NSC entirely unfolds when the oscillations exceed their normal range. The observation that neurobiological correlates of experientially opposite NSC, melancholy and mania, appear qualitatively the same is compatible with the concept that the experiential content is emerging from nonlocal consciousness. Psychedelic experiences are triggered by the administration of the psychedelic drug. However, they are influenced by nondrug factors and molded, in particular, by the individual’s mental set and the setting of the session. The transformative process can be utilized psychotherapeutically for healing and profound inner restructuring.

Is the human brain only responsive?

1995 ◽  
Vol 18 (2) ◽  
pp. 365-366
Author(s):  
Rumyana Kristeva-Feige ◽  
Bernd Feige
Keyword(s):  
Human Brain ◽  
Spontaneous Activity ◽  
Cognitive Functions ◽  
Evoked Potential ◽  
Imaging Techniques ◽  
Brain Activity ◽  
External Events ◽  
Potential Methods ◽  
The Brain

AbstractPosner & Raichle's (1994) book is a fascinating and readable account of the studies the authors have conducted on the localization of cognitive functions in the brain mainly using PET and EEC evoked potential methods. Our criticism concerns the underrepresentation of some imaging techniques (magnetoencephalography) and some forms of brain activity (spontaneous activity). Furthermore, the book leaves the reader with the impression that the brain only responds to external events.

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 Dissonance of Selected Neuroscience Techniques at Detection of Emotions in Advertising Spots

2018 ◽  
Vol 66 (4) ◽  
pp. 969-977
Author(s):  
Katarína Neomániová ◽  
Jakub Berčík ◽  
Elena Horská
Keyword(s):  
Brain Imaging ◽  
Imaging Techniques ◽  
Brain Activity ◽  
Emotional Involvement ◽  
Emotional Appeals ◽  
The Face ◽  
The Subject ◽  
Somatic Nervous System ◽  
Interdisciplinary Study ◽  
The Brain

In addition to advanced brain imaging techniques and growing interest in the study of consumer reactions with influence of marketing stimuli a new interdisciplinary study has developed on a borderland of neuroscience, economic and psychological studies – neuromarketing. Despite a certain form of insecurity whether the brain imaging technologies provide useful information for control of marketing, more and more marketers identify with their application in conventional market research. The main aim of this contribution is to clarify the influence of a selected advertising spot on the final emotional state of consumers by researching a brain activity of respondents and activity of somatic nervous system, specifically the face expressions. Cortical brain activity was detected by 16channel wireless electroencephalograph by Epoc and changes of mimic muscles were monitored by a biometric device the Facereader by Noldus. The subject of the research is the dissonance of the selected neuroscience techniques with influence of chosen advertising emotional appeals like fear, disgust and sadness. In the end of our contribution, the way of using the neuroscience technology and psychology for detection of consumer emotional involvement of consumers is explained.

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.

scholarly journals INTRODUCTION TO THE SPECIAL ISSUE OF ECONOMICS AND PHILOSOPHY ON NEUROECONOMICS

2008 ◽  
Vol 24 (3) ◽  
pp. 301-302 ◽  
Author(s):  
Giacomo Bonanno ◽  
Christian List ◽  
Bertil Tungodden ◽  
Peter Vallentyne
Keyword(s):  
Decision Making ◽  
Imaging Techniques ◽  
Brain Activity ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Special Issue ◽  
Individual Decision ◽  
The Past ◽  
Economic Choices ◽  
The Brain

The past fifteen years or so have witnessed considerable progress in our understanding of how the human brain works. One of the objectives of the fast-growing field of neuroscience is to deepen our knowledge of how the brain perceives and interacts with the external world. Advances in this direction have been made possible by progress in brain imaging techniques and by clinical data obtained from patients with localized brain lesions. A relatively new field within neuroscience is neuroeconomics, which focuses on individual decision making and aims to systematically classify and map the brain activity that correlates with decision-making that pertains to economic choices. Neuroeconomic studies rely heavily on functional magnetic resonance imaging (fMRI), which measures the haemodynamic response (that is, changes in the blood flow) related to neural activity in the brain.

Neuroimaging of the human visceral pain system–A methodological review

2011 ◽  
Vol 2 (3) ◽  
pp. 95-104 ◽  
Author(s):  
Jens Brøndum Frøkjær ◽  
Søren Schou Olesen ◽  
Carina Graversen ◽  
Trine Andresen ◽  
Dina Lelic ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Temporal Resolution ◽  
High Spatial Resolution ◽  
Visceral Pain ◽  
Imaging Techniques ◽  
Brain Activity ◽  
Pharmacological Intervention ◽  
Pain Processing ◽  
Pain Mechanisms ◽  
The Brain

AbstractDuring the last decades there has been a tremendous development of non-invasive methods for assessment of brain activity following visceral pain. Improved methods for neurophysiological and brain imaging techniques have vastly increased our understanding of the central processing of gastrointestinal sensation and pain in both healthy volunteers as well as in patients suffering from gastrointestinal disorders. The techniques used are functional magnetic resonance imaging (fMRI), positron emission tomography (PET), electroencephalography (EEG)/evoked brain potentials (EPs), magnetoencephalography (MEG), single photon emission computed tomography (SPECT), and the multimodal combinations of these techniques. The use of these techniques has brought new insight into the complex brain processes underlying pain perception, including a number of subcortical and cortical regions, and paved new ways in our understanding of acute and chronic pain. The pathways are dynamic with a delicate balance between facilitatory and inhibitory pain mechanisms, and with modulation of the response to internal or external stressors with a high degree of plasticity. Hence, the ultimate goal in imaging of pain is to follow the stimulus response throughout the neuraxis.Brain activity measured by fMRI is based on subtracting regional changes in blood oxygenation during a resting condition from the signal during a stimulus condition, and has high spatial resolution but low temporal resolution. SPECT and PET are nuclear imaging techniques where radiolabeled molecules are injected with visualization of the distribution, density and activity of receptors in the brain allowing not only assessment of brain activity but also study of receptor sites. EEG is based on assessment of electrical activity in the brain, and recordings of the resting EEG and evoked potentials following an external stimulus are used to study normal visceral pain processing, alterations of pain processing in different patient groups and the effect of pharmacological intervention. EEG has high temporal resolution, but relative poor spatial resolution, which however to some extent can be overcome by applying inverse modelling algorithms and signal decomposition procedures. MEG is based on recording the magnetic fields produced by electrical currents in the brain, has high spatial resolution and is especially suitable for the study cortical activation.The treatment of chronic abdominal pain is often ineffective and dissapointing, which leads to search for optimized treatment achieved on the basis of a better understanding of underlying pain mechanisms. Application of the recent improvements in neuroimaging on the visceral pain system may likely in near future contribute substantially to our understanding of the functional and structural pathophysiology underlying chronic visceral pain disorders, and pave the road for optimized individual and mechanism based treatments.The purpose of this review is to give a state-of-the-art overview of these methods, with focus on EEG, and especially the advantages and limitations of the single methods in clinical gastrointestinal pain esearch including examples from relevant studies.

Multimodal Imaging in Psychiatry: The Electroencephalogram as a Complement to Other Modalities

CNS Spectrums ◽  
1999 ◽  
Vol 4 (8) ◽  
pp. 44-57
Author(s):  
Dean F. Salisbury ◽  
Brian F. O'Donnell ◽  
Paul G. Nestor ◽  
Martha E. Shenton ◽  
Robert W. McCarley
Keyword(s):  
Multimodal Imaging ◽  
Imaging Techniques ◽  
Brain Activity ◽  
Multimodal Approach ◽  
Resonance Imaging ◽  
Anatomy And Physiology ◽  
Levels Of Detail ◽  
Underlying Causes ◽  
And Function ◽  
The Brain

ABSTRACTThe use of different imaging modalities provides the clinician and researcher with different views of anatomy and physiology at unprecedented levels of detail. Multimodal imaging allows for noninvasive measurement of structure and function in humans during complex behavior, and thus provides information about the inner workings of the brain previously unavailable. The present paper examines the various imaging techniques available, and describes their application to the clinic—in the case of epilepsy—and to research—in the case of schizophrenia. Because the electroen-cephalogram has a dynamic response in milliseconds, it provides the best temporal sensitivity of functional measures of brain activity. When coupled with high-resolution magnetic resonance imaging measures of brain structure, this multimodal approach provides a powerful tool for understanding brain activity. Clinically, the use of multimodal imaging has provided greater precision in localization of the epileptogenic focus. For researchers attempting to determine the underlying causes of schizophrenia, the use of multimodal imaging has helped lead the field away from a specific lesion view to a more distributed system abnormality view of this disorder.

scholarly journals Characterizing the Dynamical Complexity underlying Meditation

2019 ◽  
Author(s):  
Anira Escrichs ◽  
Ana Sanjuan ◽  
Selen Atasoy ◽  
Ane López-González ◽  
César Garrido ◽  
...  
Keyword(s):  
Resting State ◽  
Brain Activity ◽  
Control Group ◽  
Dynamical Regime ◽  
States Of Consciousness ◽  
Dynamical Complexity ◽  
The One ◽  
The Mind ◽  
The Brain ◽  
Over Time

AbstractOver the past 2,500 years, contemplative traditions have explored the nature of the mind using meditation. More recently, neuroimaging research on meditation has revealed differences in brain function and structure in meditators. Nevertheless, the underlying neural mechanisms are still unclear. In order to understand how meditation shapes global activity through the brain, we investigated the spatiotemporal dynamics across the whole-brain functional network using the Intrinsic Ignition Framework. Recent neuroimaging studies have demonstrated that different states of consciousness differ in their underlying dynamical complexity, i.e., how the broadness of communication is elicited and distributed through the brain over time and space. In this work, controls and experienced meditators were scanned using functional magnetic resonance imaging (fMRI) during resting-state and meditation (focused attention on breathing). Our results evidenced that the dynamical complexity underlying meditation shows less complexity than during resting-state in the meditator group but not in the control group. Furthermore, we report that during resting-state, the brain activity of experienced meditators showed higher metastability (i.e., a wider dynamical regime over time) than the one observed in the control group. Overall, these results indicate that the meditation state operates in a different dynamical regime than the resting-state.

scholarly journals Evaluation of self-generated behavior: untangling metacognitive read-out and error detection

2019 ◽  
Author(s):  
Tadeusz W. Kononowicz ◽  
Virginie van Wassenhove
Keyword(s):  
Error Detection ◽  
Performance Monitoring ◽  
Brain Activity ◽  
Time Interval ◽  
Time Resolved ◽  
Self Evaluation ◽  
Time Estimates ◽  
Oscillatory Brain Activity ◽  
Human Participants ◽  
The Brain

ABSTRACTWhen producing a duration, for instance by pressing a key for one second, the brain relies on self-generated neuronal dynamics to monitor the “flow of time”. Converging evidence has suggested that the brain can also monitor itself monitoring time. Here, we investigated which brain mechanisms support metacognitive inferences when self-generating timing behavior. Although studies have shown that participants can reliably detect temporal errors when generating a duration (Akdogan & Balci, 2017; Kononowicz et al., 2017), the neural bases underlying the evaluation and the monitoring of this self-generated temporal behavior are unknown. Theories of psychological time have also remained silent about such self-evaluation abilities. How are temporal errors inferred on the basis of purely internally driven brain dynamics without external reference for time? We contrasted the error-detection hypothesis, in which error-detection would result from the comparison of competing motor plans with the read-out hypothesis, in which errors would result from inferring the state of an internal code for motor timing. Human participants generated a time interval, and evaluated the magnitude of their timing (first and second order behavioral judgments, respectively) while being recorded with time-resolved neuroimaging. Focusing on the neural signatures following the termination of self-generated duration, we found several regions involved in performance monitoring, which displayed a linear association between the power of α (8-14 Hz) oscillations, and the duration of the produced interval. Altogether, our results support the read-out hypothesis and indicate that first-order signals may be integrated for the evaluation of self-generated behavior.SIGNIFICANCE STATEMENTWhen typing on a keyboard, the brain estimates where the finger should land, but also when. The endogenous generation of the when in time is naturally accompanied by timing errors which, quite remarkably, participants can accurately rate as being too short or too long, and also by how much. Here, we explored the brain mechanisms supporting such temporal metacognitive inferences. For this, we contrasted two working hypotheses (error-detection vs. read-out), and showed that the pattern of evoked and oscillatory brain activity parsimoniously accounted best for a read-out mechanism. Our results suggest the existence of meta-representations of time estimates.

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