Can subjective experience cause brain activity?

Timing emerges from a hierarchy of computations ranging from early encoding of physical duration (time sensation) to abstract time representations (time perception) suitable for storage and decisional processes. However, the neural basis of the perceptual experience of time remains elusive. To address this, we dissociate brain activity uniquely related to lower-level sensory and higher-order perceptual timing operations, using event-related fMRI. Participants compared subsecond (500 msec) sinusoidal gratings drifting with constant velocity (standard) against two probe stimuli: (1) control gratings drifting at constant velocity or (2) accelerating gratings, which induced illusory shortening of time. We tested two probe intervals: a 500-msec duration (Short) and a longer duration required for an accelerating probe to be perceived as long as the standard (Long—individually determined). On each trial, participants classified the probe as shorter or longer than the standard. This allowed for comparison of trials with an “Objective” (physical) or “Subjective” (perceived) difference in duration, based on participant classifications. Objective duration revealed responses in bilateral early extrastriate areas, extending to higher visual areas in the fusiform gyrus (at more lenient thresholds). By contrast, Subjective duration was reflected by distributed responses in a cortical/subcortical areas. This comprised the left superior frontal gyrus and the left cerebellum, and a wider set of common timing areas including the BG, parietal cortex, and posterior cingulate cortex. These results suggest two functionally independent timing stages: early extraction of duration information in sensory cortices and Subjective experience of duration in a higher-order cortical–subcortical timing areas.

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Neurophenomenology of near-death experience memory in hypnotic recall: a within-subject EEG study

Scientific Reports ◽

10.1038/s41598-019-50601-6 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 4

Author(s):

Charlotte Martial ◽

Armand Mensen ◽

Vanessa Charland-Verville ◽

Audrey Vanhaudenhuyse ◽

Daniel Rentmeister ◽

...

Keyword(s):

Subjective Experience ◽

Brain Activity ◽

Alpha Activity ◽

High Density ◽

Proof Of Concept ◽

Time Period ◽

Death Experience ◽

Eeg Changes ◽

The One ◽

Near Death Experiences

Abstract The neurobiological basis of near-death experiences (NDEs) is unknown, but a few studies attempted to investigate it by reproducing in laboratory settings phenomenological experiences that seem to closely resemble NDEs. So far, no study has induced NDE-like features via hypnotic modulation while simultaneously measuring changes in brain activity using high-density EEG. Five volunteers who previously had experienced a pleasant NDE were invited to re-experience the NDE memory and another pleasant autobiographical memory (dating to the same time period), in normal consciousness and with hypnosis. We compared the hypnosis-induced subjective experience with the one of the genuine experience memory. Continuous high-density EEG was recorded throughout. At a phenomenological level, we succeeded in recreating NDE-like features without any adverse effects. Absorption and dissociation levels were reported as higher during all hypnosis conditions as compared to normal consciousness conditions, suggesting that our hypnosis-based protocol increased the felt subjective experience in the recall of both memories. The recall of a NDE phenomenology was related to an increase of alpha activity in frontal and posterior regions. This study provides a proof-of-concept methodology for studying the phenomenon, enabling to prospectively explore the NDE-like features and associated EEG changes in controlled settings.

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Decoding Music-Evoked Emotions in the Auditory and Motor Cortex

Cerebral Cortex ◽

10.1093/cercor/bhaa373 ◽

2020 ◽

Author(s):

Vesa Putkinen ◽

Sanaz Nazari-Farsani ◽

Kerttu Seppälä ◽

Tomi Karjalainen ◽

Lihua Sun ◽

...

Keyword(s):

Auditory Processing ◽

Instrumental Music ◽

Emotional Processing ◽

Subjective Experience ◽

Neural Circuits ◽

Brain Activity ◽

Neural Basis ◽

Film Clips ◽

Cortical Regions ◽

Multivariate Pattern

Abstract Music can induce strong subjective experience of emotions, but it is debated whether these responses engage the same neural circuits as emotions elicited by biologically significant events. We examined the functional neural basis of music-induced emotions in a large sample (n = 102) of subjects who listened to emotionally engaging (happy, sad, fearful, and tender) pieces of instrumental music while their hemodynamic brain activity was measured with functional magnetic resonance imaging (fMRI). Ratings of the four categorical emotions and liking were used to predict hemodynamic responses in general linear model (GLM) analysis of the fMRI data. Multivariate pattern analysis (MVPA) was used to reveal discrete neural signatures of the four categories of music-induced emotions. To map neural circuits governing non-musical emotions, the subjects were scanned while viewing short emotionally evocative film clips. The GLM revealed that most emotions were associated with activity in the auditory, somatosensory, and motor cortices, cingulate gyrus, insula, and precuneus. Fear and liking also engaged the amygdala. In contrast, the film clips strongly activated limbic and cortical regions implicated in emotional processing. MVPA revealed that activity in the auditory cortex and primary motor cortices reliably discriminated the emotion categories. Our results indicate that different music-induced basic emotions have distinct representations in regions supporting auditory processing, motor control, and interoception but do not strongly rely on limbic and medial prefrontal regions critical for emotions with survival value.

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A Dynamic Affective Core to Bind the Contents, Context, and Value of Conscious Experience

10.1101/2021.05.20.444839 ◽

2021 ◽

Author(s):

Kenneth T. Kishida ◽

L. Paul Sands

Keyword(s):

Subjective Experience ◽

Dopaminergic System ◽

Behavioral Control ◽

Brain Activity ◽

Conscious Experience ◽

Dynamic Nature ◽

Dynamic Changes ◽

Open Questions ◽

Foundational Work ◽

The Hard Problem

The private and dynamic nature of conscious subjective experience poses an empirical challenge that has led neuroscience-based theories about consciousness to note the importance of 'the hard problem' of explaining how subjective phenomenal experience can arise from neural activity but set it aside and focus on the 'easier' problems associated with information representation and behavior. This approach leaves a major gap in our understanding of the neural mechanisms underlying conscious subjective experience and its dynamic nature. However, computational methods integrated with a variety of tools for measuring human brain activity are beginning to link dynamic changes in subjective affect with reproducible neurobehavioral signals in humans. In particular, research applying computational reinforcement learning theory has shown tremendous utility in investigating human choice behavior and the role the dopaminergic system plays in dynamic behavioral control. This research is beginning to reveal an explicit connection between the dynamics of dopaminergic signals and dynamic changes in subjective affect. However, it should be obvious that the dopaminergic system alone is not sufficient to explain all of the complexities of affective dynamics. We review foundational work, highlight current problems and open questions, and propose a Dynamic Affective Core Hypothesis that integrates advances in our understanding of the representation of the content and context of conscious experiences with our nascent understanding about how these representations acquire and retain affective subjective value.

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Rapid neural categorization of facelike objects predicts the perceptual awareness of a face (face pareidolia)

10.1101/2021.02.19.431826 ◽

2021 ◽

Author(s):

Diane Rekow ◽

Jean-Yves Baudouin ◽

Renaud Brochard ◽

Bruno Rossion ◽

Arnaud Leleu

Keyword(s):

Face Perception ◽

Subjective Experience ◽

Brain Activity ◽

List Type ◽

Perceptual Awareness ◽

Face Categorization ◽

Illusory Perception ◽

Neural Signature ◽

Scalp Electroencephalogram ◽

Human Faces

AbstractThe human brain rapidly and automatically categorizes faces vs. other visual objects. However, whether face-selective neural activity predicts the subjective experience of a face – perceptual awareness – is debated. To clarify this issue, here we use face pareidolia, i.e., the illusory perception of a face, as a proxy to relate the neural categorization of a variety of facelike objects to conscious face perception. In Experiment 1, scalp electroencephalogram (EEG) is recorded while pictures of human faces or facelike objects – in different stimulation sequences – are interleaved every second (i.e., at 1 Hz) in a rapid 6-Hz train of natural images of nonface objects. Participants do not perform any explicit face categorization task during stimulation, and report whether they perceived illusory faces post-stimulation. A robust categorization response to facelike objects is identified at 1 Hz and harmonics in the EEG frequency spectrum with a facelike occipito-temporal topography. Across all individuals, the facelike categorization response is of about 20% of the response to human faces, but more strongly right-lateralized. Critically, its amplitude is much larger in participants who report having perceived illusory faces. In Experiment 2, facelike or matched nonface objects from the same categories appear at 1 Hz in sequences of nonface objects presented at variable stimulation rates (60 Hz to 12 Hz) and participants explicitly report after each sequence whether they perceived illusory faces. The facelike categorization response already emerges at the shortest stimulus duration (i.e., 17 ms at 60 Hz) and predicts the behavioral report of conscious perception. Strikingly, neural facelike-selectivity emerges exclusively when participants report illusory faces. Collectively, these experiments characterize a neural signature of face pareidolia in the context of rapid categorization, supporting the view that face-selective brain activity reliably predicts the subjective experience of a face from a single glance at a variety of stimuli.Highlights- EEG frequency-tagging measures the rapid categorization of facelike objects- Facelike objects elicit a facelike neural categorization response- Neural face categorization predicts conscious face perception across variable inputs

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A mechanistic model of the neural entropy increase elicited by psychedelic drugs

Scientific Reports ◽

10.1038/s41598-020-74060-6 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Rubén Herzog ◽

Pedro A. M. Mediano ◽

Fernando E. Rosas ◽

Robin Carhart-Harris ◽

Yonatan Sanz Perl ◽

...

Keyword(s):

Subjective Experience ◽

Brain Activity ◽

Mechanistic Model ◽

Mechanistic Explanation ◽

Long Term Effects ◽

Whole Brain ◽

Entropy Increase ◽

Psychedelic Drugs ◽

Brain Entropy

Abstract Psychedelic drugs, including lysergic acid diethylamide and other agonists of the serotonin 2A receptor (5HT2A-R), induce drastic changes in subjective experience, and provide a unique opportunity to study the neurobiological basis of consciousness. One of the most notable neurophysiological signatures of psychedelics, increased entropy in spontaneous neural activity, is thought to be of relevance to the psychedelic experience, mediating both acute alterations in consciousness and long-term effects. However, no clear mechanistic explanation for this entropy increase has been put forward so far. We sought to do this here by building upon a recent whole-brain model of serotonergic neuromodulation, to study the entropic effects of 5HT2A-R activation. Our results reproduce the overall entropy increase observed in previous experiments in vivo, providing the first model-based explanation for this phenomenon. We also found that entropy changes were not uniform across the brain: entropy increased in some regions and decreased in others, suggesting a topographical reconfiguration mediated by 5HT2A-R activation. Interestingly, at the whole-brain level, this reconfiguration was not well explained by 5HT2A-R density, but related closely to the topological properties of the brain’s anatomical connectivity. These results help us understand the mechanisms underlying the psychedelic state and, more generally, the pharmacological modulation of whole-brain activity.

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Neural correlates of the DMT experience assessed with multivariate EEG

Scientific Reports ◽

10.1038/s41598-019-51974-4 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 19

Author(s):

Christopher Timmermann ◽

Leor Roseman ◽

Michael Schartner ◽

Raphael Milliere ◽

Luke T. J. Williams ◽

...

Keyword(s):

Subjective Experience ◽

Brain Activity ◽

Plasma Concentrations ◽

Oscillatory Activity ◽

Visual Component ◽

Eyes Closed ◽

Drug Plasma Concentrations ◽

Drug Plasma ◽

Oscillatory Power ◽

Signal Diversity

AbstractStudying transitions in and out of the altered state of consciousness caused by intravenous (IV) N,N-Dimethyltryptamine (DMT - a fast-acting tryptamine psychedelic) offers a safe and powerful means of advancing knowledge on the neurobiology of conscious states. Here we sought to investigate the effects of IV DMT on the power spectrum and signal diversity of human brain activity (6 female, 7 male) recorded via multivariate EEG, and plot relationships between subjective experience, brain activity and drug plasma concentrations across time. Compared with placebo, DMT markedly reduced oscillatory power in the alpha and beta bands and robustly increased spontaneous signal diversity. Time-referenced and neurophenomenological analyses revealed close relationships between changes in various aspects of subjective experience and changes in brain activity. Importantly, the emergence of oscillatory activity within the delta and theta frequency bands was found to correlate with the peak of the experience - particularly its eyes-closed visual component. These findings highlight marked changes in oscillatory activity and signal diversity with DMT that parallel broad and specific components of the subjective experience, thus advancing our understanding of the neurobiological underpinnings of immersive states of consciousness.

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Feeling as knowing — Part II

Consciousness & Emotion ◽

10.1075/ce.2.1.04jar ◽

2001 ◽

Vol 2 (1) ◽

pp. 75-102 ◽

Cited By ~ 7

Author(s):

Timo Järvilehto

Keyword(s):

Emotional Expression ◽

Subjective Experience ◽

Brain Activity ◽

Local Character ◽

Behavioral Observations ◽

The Social ◽

Personal Consciousness ◽

The Individual ◽

The Given ◽

The Brain

In the latter part of this two-article sequence, the concept of emotion as reorganization of the organism-environment system is developed further in relation to consciousness, subjective experience and brain activity. It is argued that conscious emotions have their origin in reorganizational changes in primitive co-operative organizations, in which they get a more local character with the advent of personal consciousness and individuality, being expressed in conscious emotions. However, the conscious emotion is not confined to the individual only, but it gets its content and the emotional quale in the social context, and in relation to the norms of the given culture. Emotion is fundamentally the process of ascription of meaning to the parts of the world which are relevant in the achievement of results of behavior. Although emotions may be studied as reorganizational processes in the organism-environment system with the help of physiological recordings and behavioral observations, it is argued — in contrast to the mainstream cognitive science — that emotions cannot be localized in the brain, although the brain is important in their generation as a part of the organism-environment system. It is suggested that the parts of the brain most closely related to emotional expression contain neurons subserving functional systems which are formed in early development, and which are therefore most intimately related to reorganizational processes in the organism-environment system.

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