Subjective signal strength distinguishes reality from imagination

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: March 23, 2023

Humans are voracious imaginers, with internal simulations supporting memory, planning and decision-making. Because the neural mechanisms imagery overlap those perception, a foundational question is how reality imagination kept apart. One possibility that intention to imagine used identify discount self-generated signals during imagery. Alternatively, because internally generated generally weaker, sensory strength index reality. Traditional psychology experiments struggle investigate this issue as subjects can rapidly learn real stimuli in play. Here, we combined one-trial-per-participant psychophysics computational modelling neuroimaging show imagined perceived fact intermixed, judgments of being determined by whether intermixed signal strong enough cross threshold. A consequence account when virtual or enough, they become subjectively indistinguishable from

Language: Английский

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Knowing-How and Knowing-That

Published: March 5, 2025

Language: Английский

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Neural Mechanisms and Psychology of Psychedelic Ego Dissolution

Pharmacological Reviews, Journal Year: 2022, Volume and Issue: 74(4), P. 876 - 917

Published: Sept. 9, 2022

Neuroimaging studies of psychedelics have advanced our understanding hierarchical brain organization and the mechanisms underlying their subjective therapeutic effects. The primary mechanism action classic is binding to serotonergic 5-HT2A receptors. Agonist activity at these receptors leads neuromodulatory changes in synaptic efficacy that can a profound effect on message-passing brain. Here, we review cognitive neuroimaging evidence for effects psychedelics: particular, influence selfhood subject-object boundaries-known as ego dissolution-surmised underwrite Agonism receptors, located apex cortical hierarchy, may particularly powerful sentience consciousness. These endure well after pharmacological half-life, suggesting neural plasticity play role efficacy. Psychologically, this be accompanied by disarming resistance increases repertoire perceptual hypotheses affords alternate pathways thought behavior, including those undergird selfhood. We consider interaction between neuromodulation through lens predictive coding, which speaks value how make sense world specific predictions about effective connectivity hierarchies tested using functional neuroimaging. SIGNIFICANCE STATEMENT: Classic bind Their agonist efficacy, resulting information processing synthesize an abundance imaging research with psychological interpretations informed framework coding. Moreover, coding suggested offer more sophisticated findings bridging large-scale networks.

Language: Английский

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Challenging Knowledge

Published: March 3, 2025

Abstract Starting-point epistemology (SPE) is a new position that, coupled with agent-centered rationality, the key to resolving philosophical scepticism. SPE acknowledges that metacognitively sophisticated agents know they things and (something) about methods by which this happens. Agent-centered rationality implies agent should only desert knowledge claim because of challenge recognize be fatal claim. Scepticism metacognitive pathology: except in those rare cases when an individual cognitively damaged, sceptical arguments fail. This book studies various ways healthy can protect themselves from prematurely distrusting what take know. A results agent’s failure correctly monitor their own processes knowledge-gathering. Example: An p challenged presenting scenarios ¬p. These are characterized as logically compatible evidence had agent. But logical possibility isn’t coextensive epistemic possibility. The former allows no regard challenging claims excludes every concerned with. Giving possible illustrates stand ground inappropriately challenged: for example, yielding where being presented too remote seriously. It’s shown how Cartesian Pyrrhonian scepticism turn on failures appropriately evaluate one’s knowledge-gathering methods.

Language: Английский

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Imagining the future self through thought experiments

Trends in Cognitive Sciences, Journal Year: 2023, Volume and Issue: 27(5), P. 446 - 455

Published: Feb. 17, 2023

The ability of the mind to conceptualize what is not present essential. It allows us reason counterfactually about might have happened had events unfolded differently or another course action been taken. think happen - perform 'Gedankenexperimente' (thought experiments) before we act. However, cognitive and neural mechanisms mediating this are poorly understood. We suggest that frontopolar cortex (FPC) keeps track evaluates alternative choices (what done), whereas anterior lateral prefrontal (alPFC) compares simulations possible future scenarios do) their reward values. Together, these brain regions support construction suppositional scenarios.

Language: Английский

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Omission responses in local field potentials in rat auditory cortex

BMC Biology, Journal Year: 2023, Volume and Issue: 21(1)

Published: May 30, 2023

Non-invasive recordings of gross neural activity in humans often show responses to omitted stimuli steady trains identical stimuli. This has been taken as evidence for the coding prediction or error. However, such omission from invasive cellular-scale animal models is scarce. Here, we sought characterise using extracellular auditory cortex anaesthetised rats. We profiled across local field potentials (LFP), analogue multiunit (AMUA), and single/multi-unit spiking activity, that were fixed-rate acoustic noise bursts where 5% randomly omitted.

Language: Английский

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The nested hierarchical model of self and its non-relational vs relational posttraumatic manifestation: an fMRI meta-analysis of emotional processing

Molecular Psychiatry, Journal Year: 2024, Volume and Issue: 29(9), P. 2859 - 2872

Published: March 21, 2024

Language: Английский

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Neural Representations in Visual and Parietal Cortex Differentiate between Imagined, Perceived, and Illusory Experiences

Journal of Neuroscience, Journal Year: 2023, Volume and Issue: 43(38), P. 6508 - 6524

Published: Aug. 15, 2023

Humans constantly receive massive amounts of information, both perceived from the external environment and imagined internal world. To function properly, brain needs to correctly identify origin information being processed. Recent work has suggested common neural substrates for perception imagery. However, it remained unclear how differentiates between experiences with shared codes. Here we tested this question in human participants (male female) by systematically investigating processes underlying generation maintenance visual voluntary imagery, veridical perception, illusion. The inclusion illusion allowed us differentiate objective subjective internality: while an objectively can be viewed as involuntary is also subjectively having like perception. Combining fMRI, eye-tracking, multivariate decoding, encoding approaches, observed superior orientation representations parietal cortex during imagery compared conversely early cortex. This dominance gradually developed along a posterior-to-anterior cortical hierarchy cortex, emerged epoch sustained into delay epoch, persisted across varied contents. Moreover, representational strength was more comparable but suggesting content-specific experiences, opposed These findings together support domain-general engagement internally generated experience. SIGNIFICANCE STATEMENT How does experiences? current study revealed enhanced stimulus-specific originating supporting experience principle further validated evidence illusion, wherein resembled at different levels hierarchy. Our provide direct critical role region offer new insights mechanisms differentiation experiences.

Language: Английский

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Spatiotemporal dynamics of self-generated imagery reveal a reverse cortical hierarchy from cue-induced imagery

Cell Reports, Journal Year: 2023, Volume and Issue: 42(10), P. 113242 - 113242

Published: Oct. 1, 2023

Visual imagery allows for the construction of rich internal experience in our mental world. However, it has remained poorly understood how derives volitionally as opposed to being cue driven. Here, using electroencephalography and functional magnetic resonance imaging, we systematically investigate spatiotemporal dynamics self-generated by having participants imagining one orientations from a learned pool. We contrast with cue-induced imagery, where imagined line based on associative cues acquired previously. Our results reveal overlapping neural signatures imagery. Yet, these display substantially differential sensitivities two types imagery: is supported an enhanced involvement anterior cortex representing contents. By contrast, representations posterior visual cortex. These jointly support reverse cortical hierarchy generating maintaining contents versus externally cued

Language: Английский

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To be or not to be hallucinating: Implications of hypnagogic/hypnopompic experiences and lucid dreaming for brain disorders

PNAS Nexus, Journal Year: 2023, Volume and Issue: 3(1)

Published: Dec. 19, 2023

The boundaries between waking and sleeping-when falling asleep (hypnagogic) or up (hypnopompic)-can be challenging for our ability to monitor interpret reality. Without proper understanding, bizarre but relatively normal hypnagogic/hypnopompic experiences can misinterpreted as psychotic hallucinations (occurring, by definition, in the fully awake state), potentially leading stigma misdiagnosis clinical contexts misconception bias research contexts. This Perspective proposes that conceptual practical understanding differentiating from may offered lucid dreaming, state which one is aware of dreaming while sleeping. I first introduce a possible systematization phenomenological range occur transition REM (including hypnagogic perceptions, symptoms, sleep paralysis, false awakenings, out-of-body experiences). then outline how metacognitive strategies used dreamers gain/confirm oneiric lucidity could tested better hallucinations. relevance analyzed schizophrenia narcolepsy, discussed neurodegenerative diseases, particularly Lewy-body disorders (i.e. Parkinson's disease, disease dementia, dementia with Lewy bodies), offering testable hypotheses empirical investigation. Finally, emotionally positive dreams triggered enhanced training/induction pathological process have intrinsic therapeutic value if properly recognized guided. overall intention raise awareness foster further about diagnostic, prognostic, implications brain disorders.

Language: Английский

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