Cerebral Cortex Communications

Early life stress (ELS) in primates alters dopamine function, contributing to addiction, hyperactivity, cognitive deficits, aggression, and social subordinance. To assess whether dopamine receptor densities are affected by ELS, male juvenile rhesus monkeys (Macaca mulatta) were either mother-reared (MR, N=6) in a semi-natural environment or nursery-reared (NR, N=6) with peers in a laboratory. At 1 [1/2] years of age, subjects were sacrificed and the left prefrontal cortex (PFC), striatum (caudate and putamen), nucleus accumbens (NAcc), and claustrum (CLA) were explored through quantitative autoradiographic studies of dopamine receptor-1 (DRD1) and -2 (DRD2) conducted using [125I]-(+)-SCH 23982 and 125I-Epidepride, which have high affinity and selectivity for DRD1 and DRD2, respectively. No group differences emerged in striatal or NAcc receptor binding. However, MR monkeys exhibited significantly greater DRD1 binding in the left orbital PFC and significantly greater DRD2 binding in both the left medial PFC and right CLA compared to NR. These findings implicate the medial PFC (stress vulnerability, cognition), orbital PFC (reward valuation), and CLA (anxiety modulation) as critical sites disrupted by maternal deprivation. Therefore, we propose that nursery-rearing induces a hypodopaminergic prefrontal-claustral ecophenotype, underlying the cognitive, affective, and social impairments observed in NR monkeys.

In our daily lives we encounter a myriad of things with which we might need to interact as we navigate our environment. Mental representations of these things must be computed and stored in our brains to be manipulated to support cognition. How are such representations organized in the brain? Several proposals have been put forth on what the principles of organization of object information in the brain might be: within ventral temporal cortex - regions thought to support object recognition - possible dimensions include the animacy status of target stimuli, their real size, their texture and material properties, and potentially their graspable status, amongst others. Here we used functional magnetic resonance imaging (fMRI) and multivariate approaches to discriminate patterns of activation for different categories of objects to test the role of these dimensions as organizing principles of object information in the brain. We show that pattern discriminability between different categories of objects does not seem to follow differences in their animacy status in any continuous way. Moreover, graspability of the target stimuli and their haptic texture properties are better predictors of representational content within ventral temporal cortex than animacy and real size. These results are in line with recent studies demonstrating the importance of computational contingencies superimposed by bi-directional functional coupling between parietal regions dedicated to the processing of object manipulation and grasping and ventral temporal regions responsible for object recognition, potentially involving material and texture processing.

The perception of God can be as a transcendent entity that is infinite and outside of human beings, typical for religious traditions, or as an immanent entity that is outside and inside of human beings, typical for mystical traditions. These different perceptions of God may be associated with different neural correlates depending on which God we pray to. To elucidate the neural correlates of these different perceptions of the divine, we compared fMRI activation during praying between 18 Christians and 16 practitioners of Sahaja Yoga Meditation, characterised by transcendent and immanent perceptions of God, respectively. The thalamus was deactivated during praying in Meditators relative to Christians. Due to the sensory relay function of thalamus, the thalamic deactivation in meditators presumably reflects a reduction in the perception of external stimuli in order to focus on the internal perception of an immanent God, while the activation of the thalamus in Christian prayers could be associated with the dialogue with an externally perceived transcendent God.

Orca, wolves, chimpanzees and humans share a similarly impressive capacity for group hunting, where individuals coordinate behaviour together to capture prey. Studying hunting behaviours has important implications for understanding how behaviour in group contexts may be indicative of cognitive decline. Despite growing interest in brain circuits for prey capture, the brain regions involved in tracking prey during a hunt and the behaviours in group hunt linked to success remain unclear. Here we combined functional near infrared spectroscopy (fNIRS) and a virtual minecraft world to examine behaviour, brain dynamics and brain synchrony involved in group hunting behaviour. We focused on the prefrontal cortex (PFC) due to its known role in planning and social coordination and recorded from pairs of individuals as they either cooperated to hunt another person (prey) or simply followed another person. Hunters were more successful if they managed to keep a smaller distance to the prey and moved at speeds that were more synchronised with their co-predator. At high-range frequencies for fNIRS (0.1-0.2Hz), we found greater brain-to-brain synchrony in lateral and medial (frontopolar) PFC regions during hunting compared with chance levels. Together, these findings provide insights into what behaviours and brain dynamics associated with successful group hunting.

A recent theoretical model of action stopping posits that the reactive cancellation of movement is underpinned by two dissociable processes: a rapid, involuntary "pause" that transiently suppresses motor output, and a slower, voluntary, suppression/retuning of motor output. Notably, the pause process has been posited to generalise broadly to infrequent and salient stimuli (irrespective of whether they bear an imperative to stop) and to be observable as suppression in electromyographical (EMG) recordings in the responding muscles. Over two experiments (N = 24 in each), participants completed standard stop signal and flanker tasks, and novel flanker task variants, where flanking arrows occurred infrequently (33% of trials), with or without a delay relative to the central imperative stimulus, or coincident with a stop signal. Presenting flankers infrequently specifically increased slowing to incongruent trials, with no effect on congruent or neutral trials (relative to a condition with flankers on every trial), and only after at least three preceding trials with no flanking stimuli. Critically, this was observed while carefully controlling for trial sequence effects. When flanker stimuli were presented infrequently, and after a delay, they did not reliably elicit suppression of EMG. These results highlight the contextual specificity with salient infrequent stimuli elicit behavioural slowing and EMG suppression, challenging the notion of a broadly generalisable pause process. Trial-level assessment of stopping speed using EMG revealed an effect of stimulus salience, whereby stop signals that occurred synchronously with Flanker arrows resulted in faster stopping than stop signals without Flanker arrows. Interestingly, this effect was specific to the faster end of stopping time distributions. Collectively, these results challenge interpretations which attribute electromyographic partial responses to specific neural pathways or mechanisms.

The availability of a pre-existing cognitive-motor schema accelerates the learning of novel motor information. The encoding of a novel schema-compatible, compared to-incompatible, motor sequence was recently shown to be supported by the left primary motor cortex (M1). However, causal evidence for the role of M1 in schema-mediated motor learning is currently lacking. In the current study, we aimed to address this knowledge gap by transiently disrupting M1 using inhibitory continuous theta burst stimulation (cTBS). Forty-eight young healthy participants learned a bimanual motor sequence task (cognitive-motor schema). Twenty-four hours later, they learned a novel sequence whose ordinal schematic structure was compatible with that learned on the previous day. To provide causal evidence for a role of M1 on such schema-mediated motor learning, we applied either cTBS or sham stimulation to the left M1 immediately prior to encoding the schema-compatible novel sequence. Electromyography results showed no evidence for an effect of left M1 cTBS on corticospinal excitability as measured with motor-evoked potentials. Similarly, behavioral results indicated no significant effect of cTBS on subsequent schema-mediated motor sequence learning. Altogether, the present data do not provide evidence for a causal role of the left M1 in schema-mediated motor sequence learning.

Everyday decisions unfold dynamically, with commitment shaped by a growing sense of urgency that can, when excessive, contribute to impulsive choices. Here we aimed at dissociating two modes of urgency regulation, control-driven (accuracy-oriented) and reward-driven (motivation-based), and asked whether their relative influence varies across individuals differing in impulsivity. We further investigated how these regulatory modes are implemented in the motor system, focusing on two modulatory effects: surround inhibition and broad modulation. Healthy participants, whose impulsivity was assessed with the UPPS urgency dimension, performed a modified Tokens task crossing control demands (low vs high control blocks) with motivational context (low vs high reward trials). In two separate sessions, single-pulse TMS was applied either over the hand motor representation to probe corticospinal excitability indexing surround inhibition, or over the leg representation to index broad modulations of motor activity. This design successfully dissociated the two regulatory modes: control-driven adjustments (across blocks) were most evident in less impulsive participants, whereas reward-driven adjustments (across trials) were most evident in more impulsive participants. Consistent with this dissociation, control-driven urgency regulation was associated with broad modulation of motor activity, whereas reward-driven urgency adjustments were associated with changes in surround inhibition. These motor signatures may serve as probes of the respective contributions of control- and reward-driven regulation even when they are not explicitly dissociated. Our findings suggest that impulsivity may not simply reflect "more urgency" but a different weighting of the influences that shape it during decision making, a hypothesis that can now be tested in clinical conditions.

In humans, the first year of life is characterized by rapid developmental changes, including substantial brain maturation. As a result, neural responses to auditory stimuli undergo marked changes during this period. In this study, we followed 69 infants across their first year of life and recorded high-density electroencephalography (hdEEG) at 2 weeks, 6 months, and 12 months postpartum. Infants were presented with pure beep tones to examine the development of neural responses to auditory stimulation. We analysed event-related potentials (ERPs), inter-trial phase coherence (ITPC), and time-frequency (TF) responses to the beep tones and controlled for arousal state during stimulus presentation. We found that with increasing age, neural responses became more pronounced and showed reduced trial-to-trial variability. Phase synchronization increased from 2 weeks to later developmental stages in a broad low-frequency range (0 to 11 Hz), indicating improved temporal alignment of brain responses over time. However, phase synchronization decreased from 6 to 12 months, suggesting a developmental transition towards more differentiated brain activity. Taken together, these findings demonstrate that auditory maturation during the first year of life follows a non-linear trajectory driven by dynamic changes in neural synchronization, reflecting the progressive refinement of functional neural circuits. Our results thus provide a critical benchmark for understanding the neural dynamics underlying sensory development during this period. Impact StatementLongitudinal high-density EEG recordings reveal that neural responses to auditory stimuli undergo non-linear developmental changes during the first year of life, driven by dynamic shifts in neural synchronization that reflect progressive refinement of auditory neural processing.

A central question in visual word recognition concerns whether orthographic and phonological codes are coordinated sequentially or in parallel during lexical access. Korean Hangul, an alpha-syllabic writing system with morphophonemic spelling principles, allows independent manipulation of orthographic and phonological syllable overlap within a single experimental design. In a masked priming lexical decision task with EEG, we contrasted orthographically identical primes (e.g., -), phonologically overlapping primes (e.g., -), and unrelated primes. Event-related potentials and time-frequency representations (theta: 4-8 Hz, lower beta: 13-20 Hz, upper beta: 20-30 Hz) were analyzed to capture both evoked and oscillatory neural dynamics. Orthographic priming produced a cascade of facilitative effects: early fronto-central P200 enhancement (150-250 ms) with upper beta synchronization (30-290 ms), followed by centro-parietal N400 reduction (350-550 ms) with frontal theta suppression (400-730 ms), and behavioral facilitation. Phonological priming, by contrast, elicited sustained lower beta activity over central regions (310-590 ms) but produced no early electrophysiological modulation and no behavioral facilitation. This spatiotemporal dissociation provides converging neural evidence that orthographic syllable processing emerges at pre-lexical stages and cascades into lexical-level processing, whereas phonological syllable effects are confined to later stages of lexical access. These findings provide support for a sequential or cascaded account of orthographic-phonological coordination, as predicted by dual-route models, while challenging strong forms of parallel activation, and suggest that the alpha-syllabic structure of Korean may enable a processing strategy in which orthographic parsing serves as an efficient entry route to the lexicon.

Humanity has always admired and created artwork, but the neurocognitive mechanisms behind artistic experience are still elusive. Professional artists and their intimate relationship with their artworks provide a unique opportunity to study the nature of art experience due to their expertise in both art making and art appreciation. During two fMRI tasks, professional artists (N=20) made aesthetic judgments on their own and other artists paintings (aesthetic appreciation task); they also mentally reconstructed the moments when they conceived their artworks or, as a control condition, when they visited now-familiar places for the first time (reconstruction by imagery task). During art appreciation of their own (as compared to other artists) paintings, participants showed stronger recruitment of bilateral posterior parietal cortices, the left lateral occipitotemporal cortex, and the dorso-central sector of the right insula, that is, action-related brain regions also involved in encoding the emotional components of movements. The reconstruction of their own artistic creation (as compared to episodic memory retrieval) involved the left fronto-parietal network associated with motor cognition. Altogether, these results suggest that the mental representations of the actions involved in creating art are integral to the overall artistic experience of painters, supporting an embodied view of the artists experience of art.

A central question in psycholinguistics in visual word recognition is whether morphologically complex words are obligatorily decomposed into stems and affixes during visual word recognition or whether whole-word access can occur when forms are frequent and familiar. The present study investigated how morphological complexity and lexical frequency jointly shape neural responses by leveraging Korean nominal inflection, whose transparent stem-suffix structure permits a clean dissociation between base (stem) frequency and surface (whole-word) frequency. Twenty-five native Korean speakers completed a rapid event-related fMRI lexical decision task involving simple and inflected nouns that varied parametrically in both frequency measures. Representational similarity analysis (RSA) revealed robust encoding of surface frequency--but not base frequency--in the inferior frontal gyrus (IFG) pars opercularis and supramarginal gyrus (SMG), with significantly stronger correlations for inflected than simple nouns. Univariate analyses converged with this result: surface frequency selectively increased activation for inflected nouns in inferior parietal regions, whereas base frequency showed no reliable effects in any ROI. These findings challenge models positing obligatory pre-lexical decomposition, instead supporting accounts in which morphological processing is shaped by post-lexical, usage-driven lexical statistics. Taken together, our findings shed light on a distributed perspective on morphological processing, suggesting that structural and statistical factors jointly constrain access to morphologically complex forms.

The striatum comprises two neurochemically and anatomically distinct tissue compartments, the striosome and matrix, that are hypothesized to support different aspects of cognition and action. In animal studies, the striosome has been linked to reward evaluation, emotional learning, and decision-making under conflict, whereas the matrix is more closely associated with sensorimotor integration and task execution. However, evidence for compartment-specific function in humans is limited and indirect. Using probabilistic tractography, we identified voxels with striosome-like and matrix-like patterns of structural connectivity in healthy adults. We then examined how these compartment-like voxels responded to task demands during an fMRI n-back working-memory paradigm that visually presented four stimulus categories (body part, face, place, or tool). We assessed activation in a low-load condition (0-back, remembering a just-viewed stimulus) vs. a high-load condition (2-back, remembering a stimulus viewed two prior). Functional activation was temporally segregated and matched our prior findings in motor tasks: striosome-like voxels were preferentially engaged during the cue and initial preparation phases, whereas matrix-like voxels dominated during task execution. Trial accuracy strongly modulated striatal activation, with both compartments showing significantly greater responses during "correct" than in "error" trials. Notably, the accuracy-related increase in activation was larger in striosome-like voxels, consistent with a prominent role for striosomal processing in performance evaluation. Both striosome- and matrix-like voxels significantly increased activation from 0-back to 2-back, indicating sensitivity to working-memory load, with larger increases for matrix-like than for striosome-like voxels. Category-selective responses also differed by compartment and cognitive load. Under low working-memory load (0-back), stimulus-category effects were modest and broadly similar between compartments. Under higher load (2-back), activation in striosome-like voxels remained selective for specific stimulus categories, while matrix-like voxels lost category specificity. Together, these findings suggest that the striosome-matrix distinction generalizes from motor to cognitive domains, reflecting a conserved division between preparatory and execution-related processes that varies systematically with task demands, memory category, and performance accuracy. This convergence of compartment-specific responses across domains points to a core organizational principle of the human striatum with potential implications for neuropsychiatric diseases. Key PointsO_LIStriatal medium spiny neurons are organized into two interdigitated compartments, the striosome and matrix, which are embryologically, pharmacologically, and anatomically distinct. Compartment-specific functions have been demonstrated in animals, but their roles in human cognition are unexplored. C_LIO_LIWe found that in humans, striosome-like voxels preferentially activated during memory cues, while matrix-like voxels preferentially activated during recall and memory maintenance. In both compartments, activation scaled with task difficulty. C_LIO_LIActivation in striosome-like voxels scaled more strongly with task accuracy and difficulty, suggesting a striosome-selective role in vigilance and/or motivation. C_LI

Hierarchy in the brain emerges across spatial and temporal scales, enabling transformations from rapid sensory encoding to sustained cognitive control. Hierarchical gradients are well established in sensory systems. In contrast, the hierarchical organization of the primate motor cortex remains debated, partly due to its agranular architecture and the absence of clear laminar input-output projections, that obscures the distinction between feedforward and feedback pathways. In particular, the relative hierarchical position of the dorsal premotor cortex (PMd) and the primary motor cortex (M1) cannot be resolved from anatomy alone. To investigate their relative organization, we here adopted a multimodal approach using intrinsic timescales derived from both single-unit spiking activity (SUA) and local field potentials (LFPs) in macaques performing a delayed-match-to-sample reaching task. We found convergent evidence for inter-areal temporal hierarchy, with longer spiking timescales and smaller LFP aperiodic spectral exponents in M1. Across cortical depth, however, temporal organization depended on signal modality. LFP spectral exponents were significantly smaller in deep than superficial layers in both areas, and LFP-autocorrelation timescales were longer in deep layers in M1. In contrast, spiking activity did not show significant laminar differences in intrinsic timescales. Functionally, neurons with longer timescales exhibited more stable representations of the planned movement direction during motor preparation in PMd and slower temporal evolution of movement encoding during execution in both areas. In conclusion, multimodal temporal measures converge on the same hierarchical organization across these two motor areas, with M1 placed higher than PMd. Our study provides the first characterization of intrinsic spiking timescales across cortical layers in any cortical area and shows that laminar temporal organization depends on the neural signal analyzed. This divergence likely reflects their distinct physiological origins. Spikes capture neuronal output, whereas LFPs primarily reflect synaptic and dendritic population activity, potentially integrating differential contributions from apical and basal dendritic inputs.

Marsupials give birth to extremely altricial offspring which must be reared externally for an extended period, often in a pouch. Despite often being considered a defining feature of marsupials, around a third of living species lack a pouch. Here, we describe the postnatal development of the gray short-tailed opossum, Monodelphis domestica, a small pouchless South American didelphid and consider its implications for life history evolution within Metatheria. We find that at birth, ossification and chondrogenesis in neonatal M. domestica is more extensive than in basal pouched Australidelphian marsupials like the dunnart. Key precocial milestones such as tarsal ossification, eye opening, growth of body fur, and chewing tooth eruption occur earlier and more rapidly. Principal component analysis of life history and reproductive traits reveals a pronounced r- to K-selected gradient across living marsupial species. Stochastic character-mapping based ancestral state reconstruction suggests that absence of the pouch, and by inference possession of an r-selected life history strategy characterised by large litters, short attachment phases, and accelerated weaning was likely ancestral amongst crown-group marsupials. The more K-selected reproductive strategy of pouched marsupials wherein there is a prolonged postnatal development window, and relative few young are produced, likely evolved during the early Cenozoic, and separately amongst australidelphian and ameridelphian marsupials. Rather than making early marsupials more sensitive to environmental disturbances, we hypothesis that their possession of an r-selected life history strategy may have been a key factor in their persistence through the K-Pg extinction.

BackgroundAudiovisual integration is essential for daily functions such as speech comprehension. It relies on a temporal constraint whereby events from different sensory modalities are perceptually bound within a limited temporal window, the audiovisual temporal binding window, defining the range of stimulus onset asynchronies perceived as synchronous. While correlational neuroimaging studies (fMRI, EEG) have implicated a distributed network in audiovisual integration, the causal neural underpinnings of the temporal binding window remain largely unknown. ObjectiveTo identify cortical regions causally supporting audiovisual simultaneity judgment. Methods: Direct electrical stimulation (DES) was prospectively applied to 62 cortical sites during awake brain surgery in 39 patients. Patients performed an audiovisual simultaneity judgment task with varying stimuli onset asynchronies alongside standard sensory-motor, language, and visuospatial tasks. Montreal Neurological Institute coordinates were obtained for all stimulated areas. ResultsDES selectively impaired audiovisual simultaneity judgments while sparing other standard tasks, in 7 highly focal, right-hemispheric cortical sites (<1 cm2). Three sites were situated around the intraparietal sulcus, and four near the supplementary motor area. Stimulation of left-hemisphere sites produced non-selective impairments, also affecting language-related tasks. ConclusionsThese findings provide causal evidence for a right-lateralized frontoparietal network, involving focal regions near the intraparietal sulcus and supplementary motor area, in audiovisual temporal integration. Given the established roles of these regions in attentional and decisional processes, this study refines their contribution to the temporal binding window network and underscores the clinical importance of preserving this network during awake brain surgery.

Perceiving others actions is essential for survival, interaction, and communication, yet most neuroscience studies rely on 2D videos or images that lack the presence and social affordances of real actions. This limits our understanding of real-world action perception and the development of neurally grounded models. Here, we directly compare behavioral and neural responses to real (live) versus video-based actions. Using a novel experimental setup (Pekcetin et al. 2023), we conducted a two-session EEG study (N = 26) in which participants viewed peripheral actions presented live or via video while performing a central task under low and high attentional load. We examined behavioral performance, mass-univariate ERPs, time-frequency responses, and time-resolved representational similarity (RSA). Behaviorally, real actions imposed a greater cognitive cost than video actions, with the largest "Realness Effect" under high load. ERPs showed reliable Live-Video differences within 150-450 ms after action onset. Time-frequency analyses over occipital and parietal regions revealed weaker alpha (8-12 Hz) and beta (15-25 Hz) suppression for video actions, indicating reduced perceptual engagement. Time-resolved RSA also robustly separated live and video conditions between 250-750 ms. Together, these results show that live actions engage perceptual systems more strongly than their video-based counterparts, underscoring the limitations of screen-mediated paradigms and motivating more ecologically grounded approaches in social and action perception research.

BackgroundThe brains glymphatic system plays a vital role in maintaining neural health. However, little is known about whether second language (L2) immersion can influence this clearance pathway. Methods50 high-proficiency L2 English speakers (mean age: 32.6 years; 78% female) were assessed for glymphatic function using three multimodal MRI markers: BOLD-CSF coupling strength (fMRI), choroid plexus ratio (structural MRI), and DTI-ALPS index (diffusion MRI). Analyses examined relationships between glymphatic markers and L2 immersion duration, age of acquisition (AOA), and active use environment, controlling for age, education, and sex. ResultsL2 immersion duration correlated significantly with better glymphatic function. Longer immersion related to better BOLD-CSF coupling strength (r = -0.315, p < 0.05) and decreased choroid plexus ratios (r = -0.39, p < 0.05), suggesting enhanced brain-CSF coordination and fewer pathological CSF production structures. Mediation analyses demonstrated that immersion influenced ALPS indirectly through effects on choroid plexus morphology and BOLD-CSF coupling. L2 AOA moderated the immersion-coupling relationship: individuals who began learning after age 9.53 showed stronger associations between immersion and BOLD-CSF coupling, though AOA did not moderate choroid plexus effects. As for L2 immersive active is associated with better glymphatic function, while L2 immersive passive and L2 non-immersive active are both unrelated. ConclusionsL2 immersion associates with better glymphatic system function through multiple pathways, including improved brain-CSF coordination, optimized choroid plexus structure, and increased perivascular flow. These findings provide novel neurobiological evidence that bilingual experience may confer neuroprotective benefits through brain waste clearance mechanisms.

Following their engagement towards differentiation, tissue stem cells often transit through a precursor state that is difficult to define because of its transient nature; similarly, the precise role of lineage precursors in implementation of tissue architecture and function is unknown. In the present work, we used two mouse models of deficient feedback regulation to characterize precursors of the pituitary corticotrope lineage that regulates the stress response. Both the POMC knockout and adrenalectomized mouse models develop glucocorticoid deficiency and compensatory accumulation of corticotrope precursors that have so far eluded characterization. We found that pre-corticotrope differentiation depends on the lineage-specific factor Tpit and is repressed by glucocorticoids. We identified brain-derived neurotrophic factor (BDNF) as the signal that engages pituitary stem cells towards differentiation in these models as well as in normal pituitary development. A glucocorticoid-sensitive BDNF autocrine loop active in pre-corticotropes turns these cells into signaling hubs for maintenance of pituitary-adrenal homeostasis. HighlightsO_LIPituitary lineage precursors expand in conditions of deficient feedback regulation C_LIO_LIBDNF mobilizes pituitary stem cells during establishment of tissue size and architecture C_LIO_LICorticotrope precursors are a signaling hub for tissue homeostasis C_LI

Numerous studies have demonstrated rapid (< 100 ms) visuo-cortical differentiation of threat-associated faces. This may be due to low-spatial frequency (LSF) visual information originating from magnocellular pathways. Yet it remains unclear whether potentially magnocellular fear signals extend beyond evolutionarily prepared emotional faces and whether they are subject to short-term neuroplasticity. If so, spatial frequency characteristics should modulate processing of faces with newly acquired threat-relevance. Furthermore, it is unknown whether sub-bands of the visual spectrum are associated with autonomic arousal. Using a differential fear-conditioning paradigm, this study tested whether early visual attentional capture, indicated by the P1 event-related potential component, prioritizes LSF information of threat-associated faces with neutral expressions. Additionally, it was tested whether such effects would be paralleled by threat differentiation in the skin conductance response (SCR). For contingency aware participants, stimulus ratings confirmed successful fear conditioning and participants showed a selective left-hemispheric enhancement of the P1 in response to LSF threat-faces. By contrast, CS differentiation in the SCR was not modulated by spatial frequencies but by stimulus duration, with longer CS presentations resulting in larger SCR to threat compared to neutral faces. For contingency unaware participants, trial-by-trial amplitudes of P1 and SCR were positively correlated. Data support the notion that magnocellular-cortical pathways adapt quickly to novel threat-associations and facilitate rapid threat retrieval even for perceptually neutral faces. However, at least in the short term, these signals do not necessarily associate with anticipatory arousal in SCR. Impact statementOur electroencephalography (EEG) study provides evidence for distinct contributions of subcortical signals during early visual perception of fear-conditioned faces (P1 event-related potential) but not autonomic arousal (skin conductance response). Instead, skin conductance responses reflected conscious anticipatory arousal irrespective of the visual pathway. Together, these results reveal parallel but dissociable mechanisms of fear perception that are differentially sensitive to visual properties of threat-associated faces.

Extended cessation (EC) is a rare, non-ordinary meditative endpoint characterized by a temporary absence of reportable phenomenal experience, followed by an extraordinary perceptual vividness, openness, equanimity and affective balance. EC thus offers a unique, non-pharmacological window into the brain dynamics underlying suspension of conscious experience and the subsequent psychological transformations. The present study investigated whole-brain electrophysiological changes induced by EC using a dense-sampling electroencephalographic microstate analysis, in five highly trained meditators. Temporal parameters and transition probabilities of canonical microstates during EC were compared with two control conditions (counting and memory tasks) across six frequency bands (broadband, delta, theta, alpha, beta, gamma). EC was characterized by alterations in global explained variance and coverage of microstates B and C, both associated with self-referential processing. Specifically, EC involved less frequent and shorter occurrences of microstate B, and more frequent and longer occurrences of microstate C. Transition probabilities also reconfigured: transitions from A and B to C increased, whereas transitions from A to B decreased. These broadband effects were distributed across delta, theta, and beta frequency sub-bands. Additional band-specific changes emerged for microstate A and D. Delta band showed longer microstate A and increased B-to-A transitions during EC, while beta band showed less frequent and shorter D and decreased bidirectional B-to-D transitions. These scalp-level findings support a precision re-weighting account of EC, reflecting self-referential reconfigurations with enhanced sensory-anchored inflow. This study provides initial evidence for the neurophysiological correlates of EC, with potential implications for human wellbeing. SIGNIFICANCE STATEMENTExtended cessation is a rare meditative state involving a voluntarily, temporary suspension of conscious experience, offering an exceptional opportunity to study how the brain supports and disrupts conscious awareness without pharmacological intervention. By applying EEG microstate analysis, this study identifies distinct large-scale neural reconfigurations during EC, particularly within microstates linked to self-referential processing. These findings suggest that EC involves a dynamic redistribution of precision and sensory-anchored processing, providing initial neurophysiological evidence for how advanced meditation may reshape conscious experience. This work advances the scientific understanding of non-ordinary states of consciousness and highlights their potential relevance for human well-being.