Anaesthesia disrupts mesoscale signal propagation in spite of enhanced responsivity in frontal but not in parietal cortex

Опубликована: Апрель 19, 2025

Summary Understanding the effects of anaesthesia on cortical signal propagation at multiple spatiotemporal scales could provide insights into how integration is disrupted during loss consciousness. Non-invasive studies indicate reduced complexity large-scale patterns following perturbation activity under anaesthesia, compared to wakefulness. However, it currently unknown cortex responds local electrical microstimulation mesoscale sensory awareness, especially in higher order areas believed be involved emergence Using planar microelectrode arrays implanted ventrolateral prefrontal (vlPFC) and posterior parietal (PPC) macaques, we simultaneously recorded administered intracortical varying amplitudes quiet wakefulness, as well light deep sevoflurane anaesthesia. We found that lateral spread rather than strength elicited was consistently Suppression underlie a breakdown integrative processes consciousness, providing novel mechanism for understanding network

Язык: Английский

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What does decoding from the PFC reveal about consciousness?

Trends in Cognitive Sciences, Год журнала: 2024, Номер 28(9), С. 804 - 813

Опубликована: Июнь 10, 2024

Язык: Английский

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Eight challenges in developing theory of intelligence

Frontiers in Computational Neuroscience, Год журнала: 2024, Номер 18

Опубликована: Июль 24, 2024

A good theory of mathematical beauty is more practical than any current observation, as new predictions about physical reality can be self-consistently verified. This belief applies to the status understanding deep neural networks including large language models and even biological intelligence. Toy provide a metaphor reality, allowing mathematically formulating (i.e., so-called theory), which updated conjectures are justified or refuted. One does not need present all details in model, but rather, abstract constructed, complex systems such brains have many sloppy dimensions much less stiff that strongly impact macroscopic observables. type bottom-up mechanistic modeling still promising modern era natural artificial Here, we shed light on eight challenges developing intelligence following this theoretical paradigm. Theses representation learning, generalization, adversarial robustness, continual causal internal model brain, next-token prediction, mechanics subjective experience.

Язык: Английский

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Parietal theta burst TMS does not modulate bistable perception

Neuroscience of Consciousness, Год журнала: 2024, Номер 2024(1)

Опубликована: Янв. 1, 2024

Abstract The role of the parietal cortex in perceptual awareness and resolving ambiguity is unsettled. Early influential transcranial magnetic stimulation studies have revealed differences conscious perception following stimulation, fuelling notion that causally contributes to ambiguity. However, central this conclusion reliability method employed. Several prior opposing effects, such as shortening, lengthening, or no effect on multistable transitions stimulation. Here we addressed continuous theta-burst (cTBS) bistable stimuli. We conducted three cTBS experiments were matched terms stimuli, protocol, target site, used a higher number participants. None our replicated results. only experiment using individual functional localizers led weak while two others null Individual variability motor did not predict effects. In view recent reports highly variable effects over cortex, results suggest particularly unreliable modulating when applied cortex.

Язык: Английский

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Uncovering the organization of neural circuits with Generalized Phase Locking Analysis

PLoS Computational Biology, Год журнала: 2023, Номер 19(4), С. e1010983 - e1010983

Опубликована: Апрель 3, 2023

Despite the considerable progress of in vivo neural recording techniques, inferring biophysical mechanisms underlying large scale coordination brain activity from data remains challenging. One obstacle is difficulty to link high dimensional functional connectivity measures mechanistic models network activity. We address this issue by investigating spike-field coupling (SFC) measurements, which quantify synchronization between, on one hand, action potentials produced neurons, and other hand mesoscopic “field” signals, reflecting subthreshold activities at possibly multiple sites. As number sites gets large, amount pairwise SFC measurements becomes overwhelmingly challenging interpret. develop Generalized Phase Locking Analysis (GPLA) as an interpretable dimensionality reduction multivariate SFC. GPLA describes dominant between field ensembles across space frequencies. show that features are biophysically when used conjunction with appropriate models, such we can identify influence circuit properties these features. demonstrate statistical benefits interpretability approach various computational Utah array recordings. The results suggest GPLA, jointly modeling, help uncover contribution recurrent microcircuits spatio-temporal dynamics observed multi-channel experimental

Язык: Английский

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The role of conflict processing in multisensory perception: behavioural and electroencephalography evidence

Philosophical Transactions of the Royal Society B Biological Sciences, Год журнала: 2023, Номер 378(1886)

Опубликована: Авг. 7, 2023

To form coherent multisensory perceptual representations, the brain must solve a causal inference problem: to decide if two sensory cues originated from same event and should be combined, or they came different events processed independently. According current models of integration, during this process, integrated (common cause) segregated (different causes) internal are entertained. In present study, we propose that process involves competition between these alternative engages mechanisms conflict processing. test hypothesis, conducted experiments, measuring reaction times (RTs) electroencephalography, using an audiovisual ventriloquist illusion paradigm with varying degrees intersensory disparities. Consistent our hypotheses, incongruent trials led slower RTs higher fronto-medial theta power, both indicative conflict. We also predicted intermediate disparities would yield power when compared congruent stimuli large disparities, owing steeper models. Although prediction was only validated in RT experiments displayed anticipated trend. conclusion, findings suggest potential involvement integration spatial information. This article is part theme issue ‘Decision control processes perception’.

Язык: Английский

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Human intralaminar and medial thalamic nuclei transiently gate conscious perception through the thalamocortical loop

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Апрель 2, 2024

Abstract Human high-order thalamic nuclei have been known to closely correlate with conscious states. However, given the great difference of states and contents (conscious perception), it is nearly unknown how those thalamocortical interactions directly contribute transient process perception. To address this question, we simultaneously recorded local field potentials (LFP) in human intralaminar, medial ventral as well prefrontal cortex (PFC), while patients implanted electrodes performing a visual consciousness task. Overall, compared nuclei, intralaminar showed earlier stronger consciousness-related activity. Moreover, neural synchrony cross-frequency coupling were both driven by theta phase during These results indicated that rather than commonly believed PFC, play decisive ‘gate’ role Highlights Intralaminar activity, comparing nuclei. transiently drove synchronization through (2-8Hz) modulation emergence consciousness. Theta activity dynamically regulated amplitude PFC more regulation on lateral other subregions

Язык: Английский

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Prefrontal cortex oscillations update and stabilize consciousness during binocular rivalry

Neuron, Год журнала: 2023, Номер 111(10), С. 1519 - 1520

Опубликована: Май 1, 2023

Язык: Английский

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Where is the ghost in the shell?

Neuroscience of Consciousness, Год журнала: 2024, Номер 2024(1)

Опубликована: Янв. 1, 2024

The neurobiology of conscious experience is one the fundamental mysteries in science. New evidence suggests that transcranial magnetic stimulation parietal cortex does not modulate bistable perception. What this mean for neural correlates consciousness, and how should we search them?

Язык: Английский

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The complexity of human subjective experience during binocular rivalry

Опубликована: Апрель 26, 2024

Our subjective experience of the sensory information is rich and complex. Yet, typical cognitive perception psychology paradigms reduce it to a few pre-defined discrete categories, like yes/no answers or Likert scales. In current study, we examined complexity visual during binocular rivalry, major experimental paradigm used study conscious its neural mechanisms. Binocular rivalry occurs when two eyes are presented with different images that cannot be fused into uniform percept. As result, alternates between brief transition phases in-between. Fifty-two subjects viewed produced by pairs stimuli (images, orthogonal gratings moving dots). After each period, they indicated how many types perceived described their type. Using content analysis identified 20 unique categories over all subjects, sessions, stimuli. On average, participants reported 2-3 for stimulus combination. The were consistent observer time but varied across content. results show perceptual transitions appear in forms depend on specific induces rivalry. findings have implications neuroimaging studies which may yield depending exact transitions. They also demonstrate underestimated traditional paradigms.

Язык: Английский

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