The magnitude and time course of pre-saccadic foveal prediction depend on the conspicuity of the saccade target

Опубликована: Фев. 7, 2025

We previously demonstrated that during the preparation of a large-scale saccadic eye movement, defining features movement target (i.e., its orientation) are anticipated in pre-saccadic foveal vision (Kroell & Rolfs, 2022). In this Research Advance, we show conspicuity orientation information at saccade location influences magnitude and time course enhancement. As our previous study, observers prepared to peripheral signal (the target) while monitoring appearance second probe) their center gaze. The probe appeared 50% trials either had same as (congruent) or different (incongruent). current manipulated opacity against 1/f background noise four logarithmic steps from 25% 90%. An increase translated an luminance contrast signal-to-noise ratio within region. made three main observations: First, Hit Rates for target-congruent incongruent probes decreased increased, presumably since attention was increasingly drawn more salient it became. Crucially, enhancement defined difference between congruent increased with opacity. Second, oscillatory pattern particularly pronounced higher opacities. Interestingly, temporal frequency these oscillations corresponded range typically associated neural feedback signaling. Third, unlike Rates, False Alarm did not vary Instead, reverse correlations suggest opacities, Alarms were triggered by signal, is, incidental noise. Beyond providing new mechanistic insights into active processing, findings relevant researchers planning adapt paradigm study related questions. Presenting high appears beneficial congruency effects, especially when time-resolved, most robustly detectable.

Язык: Английский

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Thalamic Volume Reduction in Cerebral Visual Impairment: Relationship to Visual Dysfunction

Journal of Child Neurology, Год журнала: 2025, Номер unknown

Опубликована: Фев. 17, 2025

The thalamus is critical for the relay and modulation of visual information. As such, injury to developing may result in cerebral impairment (CVI). This study investigated quantitative volume reductions compared controls probed association between thalamic severity impairment–related dysfunctions. Thalamic volumes were quantified using T1-weighted magnetic resonance imaging (MRI) data from 23 participants with 42 controls. Nineteen also completed CVI Questionnaire. Cerebral was associated significant global thalami, anterior, lateral, ventral regions, as well several nuclei, particularly those due periventricular leukomalacia. Within group, smaller right lateral pulvinar significantly more reported difficulties moving through space. Together, these results provide empirical evidence supporting aberrant development a potential mechanism underlying impairment.

Язык: Английский

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Human pulvinar stimulation engages select cortical pathways in epilepsy

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2025, Номер unknown

Опубликована: Март 13, 2025

The pulvinar has been proposed as an effective neuromodulation target for patients with posterior quadrant and temporal epilepsies. However, the a large tissue volume, multiple subnuclei, widespread cortical connections. It remains unknown whether electrical stimulation of distinct subregions affects temporal, occipital, parietal areas differently. To address this gap, we delivered single-pulse to measured resulting brain evoked potentials in twelve undergoing stereotactic EEG drug-resistant epilepsy. Brain were parameterized across cortex. Stimulation lateral elicited significant striate extrastriate that diminish shifts towards medial pulvinar. Conversely, ventral aspect produced potentials, which stimulation. We also found dorsomedial responses limited striate/extrastriate responses. These results demonstrate specific influences areas. Selective targeting maximize seizure network engagement may be essential individualized treatment

Язык: Английский

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The magnitude and time course of pre-saccadic foveal prediction depend on the conspicuity of the saccade target

Опубликована: Март 31, 2025

We previously demonstrated that during the preparation of a large-scale saccadic eye movement, defining features movement target (i.e., its orientation) are anticipated in pre-saccadic foveal vision (Kroell & Rolfs, 2022). In this Research Advance, we show conspicuity orientation information at saccade location influences magnitude and time course enhancement. As our previous study, observers prepared to peripheral signal (the target) while monitoring appearance second probe) their center gaze. The probe appeared 50% trials either had same as (congruent) or different (incongruent). current manipulated opacity against 1/f background noise four logarithmic steps from 25% 90%. An increase translated an luminance contrast signal-to-noise ratio within region. made three main observations: First, Hit Rates for target-congruent incongruent probes decreased increased, presumably since attention was increasingly drawn more salient it became. Crucially, enhancement defined difference between congruent increased with opacity. Second, showed oscillatory pattern particularly pronounced higher opacities. Third, unlike Rates, False Alarm did not vary Instead, reverse correlations suggest opacities, Alarms were triggered by signal, is, incidental noise. Beyond providing new mechanistic insights into active processing, these findings relevant researchers planning adapt paradigm study related questions. Presenting high appears beneficial congruency effects, especially when time-resolved, most robustly detectable.

Язык: Английский

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A burst-dependent thalamocortical substrate for perceptual awareness

PLoS Computational Biology, Год журнала: 2025, Номер 21(4), С. e1012951 - e1012951

Опубликована: Апрель 7, 2025

Contemporary models of perceptual awareness lack tractable neurobiological constraints. Inspired by recent cellular recordings in a mouse model tactile threshold detection, we constructed biophysical that incorporated essential features thalamocortical anatomy and physiology. Our reproduced, mechanistically explains, the key vivo neural behavioural signatures model, as well response to set causal perturbations. We generalised same (with identical parameters) more complex task – visual rivalry found thalamic-mediated mechanism determined dominance. This led generation novel, directly testable, electrophysiological predictions. Analyses based on dynamical systems theory show simulations both detection arises from emergent systems-level dynamics loops.

Язык: Английский

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A model of thalamo-cortical interaction for incremental binding in mental contour-tracing

PLoS Computational Biology, Год журнала: 2025, Номер 21(5), С. e1012835 - e1012835

Опубликована: Май 8, 2025

Object-basd visual attention marks a key process of mammalian perception. By which mechanisms this is implemented and how it can be interacted with by means attentional control not completely understood yet. Incremental binding mechanism required in demanding scenarios object-based experimentally well investigated. Attention spreads across representation the object labels bound elements constant up-modulation neural activity. The speed incremental was found to dependent on spatial arrangement distracting scene scale invariant giving rise growth-cone hypothesis. In work, we propose dynamical model that provides mechanistic account for these findings. Through simulations, investigate properties demonstrate an spreading tags neurons participate process. They utilize Gestalt eventually show characteristics labeling perceptual items delayed activity enhancement neuronal firing rates. We discuss algorithmic underlying relate our computations. This theoretical investigation encompasses complexity considerations finds only explanatory value terms neurophysiological evidence, but also efficient implementation striving establish normative account. relating connectivity motifs neuroanatomical suggest thalamo-cortical interactions likely candidate flexible realization suggested model. There, pyramidal cells are proposed serve as processors grouping information. Local bottom-up evidence about stimulus features integrated via basal dendritic sites. It combined apical signal consisting contextual information gated task-relevance selection mediated higher-order thalamic representations.

Язык: Английский

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Functional connectivity of thalamic nuclei during sensorimotor task-based fMRI at 9.4 Tesla

Frontiers in Neuroscience, Год журнала: 2025, Номер 19

Опубликована: Май 13, 2025

The thalamus is the brain's central communication hub, playing a key role in processing and relaying sensorimotor cognitive information between cerebral cortex other brain regions. It consists of specific non-specific nuclei, each with different role. Specific thalamic nuclei relay sensory motor to cortical subcortical regions ensure precise communication. In contrast, are involved general functions such as attention or consciousness through broader less targeted connections. present study, we aimed investigate functional connectivity patterns identified our previous study being (finger-tapping) (finger-touch) tasks. results this show that not static hubs predefined neural signal processing, they task-specific anterior, middle, lateral, posterior nuclei. Instead, all can flexibly change their connections response task demands. This work has important implications for understanding task-dependent using task-based fMRI at 9.4 Tesla.

Язык: Английский

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Microvascular functional and structural changes in early-stage CADASIL

Magnetic Resonance Imaging, Год журнала: 2025, Номер unknown, С. 110402 - 110402

Опубликована: Май 1, 2025

Язык: Английский

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The replication principle revisited: a shared functional organization between pulvinar-cortical and cortico-cortical connectivity and its structural and molecular imaging correlates

Опубликована: Май 21, 2025

Abstract The pulvinar, the largest nucleus in human thalamus, is a complex, highly interconnected structure. Through dense, organized network of cortical and subcortical areas, it provides adequate cooperation between neural systems, which crucial for multiple high-order functions such as perception, visuospatial attention, emotional processing. Such central role made possible by precise internal topographical organization, mirrored anatomical connections well expression neurochemical markers. While being traditionally subdivided into sub-nuclei, each characterized distinct connectional morphological features, recent studies both primate brains have highlighted that this organization only marginally aligns with conventional histological subdivision. Instead, has been delineated context continuous gradients along dorsoventral mediolateral axes. multi-gradient extensively documented models, remains relatively underexplored brain. present work combines high-quality, multi-modal structural functional imaging data recently published whole-brain, large-scale, positron emission tomography (PET) atlas detailing 19 neurotransmitters receptors distributed across By applying diffusion embedding analysis to tractography, connectivity, receptor coexpression data, we identify characterize topographically connections, coactivation, molecular binding patterns. We demonstrate converge on shared representation axes pulvinar. This transitions spanning from lower-level higher-order regions. Moreover, paralleled gradual changes markers associated key neuromodulator including serotoninergic, noradrenergic, dopaminergic, opioid systems. Our findings represent significant step forward understanding pulvinar anatomy function, offering an exploratory framework investigate structure health disease.

Язык: Английский

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Machine learning for classification of pediatric bipolar disorder with and without psychotic symptoms based on thalamic subregional structural volume

BMC Psychiatry, Год журнала: 2025, Номер 25(1)

Опубликована: Июнь 3, 2025

Язык: Английский

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