Cerebral cortex最新文献

This study is the first application of personalized temporal interference (TI) (±5 mA，10 mA peak-to-peak, Δf = 20 Hz) targeting the right striatum to systematically investigate neuromodulatory effects on functional-structural plasticity within the cortico-striato-thalamo-cortical (CSTC) network. 26 healthy participants underwent TI and sham sessions, with functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) acquired before, during, and after stimulation. TI stimulation modulated the functional connectivity (FC) within the CSTC circuit, particularly showing significant reductions in FC between the right striatum and the precentral gyrus during stimulation. Furthermore, acute increases in axial diffusivity (AD) were observed in the right corticospinal tract (CST) and anterior thalamic radiation (ATR) during stimulation, with delayed elevation in fractional anisotropy (FA) in the right ATR post-stimulation. A notable negative correlation between changes in FC and AD highlights the interplay between functional and microstructural alterations. Importantly, no adverse effects were reported, indicating safety. These findings demonstrate that personalized TI stimulation effectively modulates CSTC connectivity and induces neuroplastic changes, suggesting its potential as a therapeutic strategy for its potential for neuropsychiatric disorders.

Recent studies suggest that sustained visual attention operates rhythmically, as if the visual system periodically samples stimuli in the environment. Here, we present evidence for rhythmic sampling of internal representations of targets and distractors up to 1 s after visual stimulation offset. Twenty participants performed an anticipatory object-based visual attention task involving a short-lasting (50 ms) target object image. This task was made more challenging by the overlaid presentation of a distractor object image. We conducted a decoding analysis on stimulus-evoked electroencephalography to measure target and distractor information over the stimulus epoch, which extended almost 1,000 ms beyond the visual stimulus offset. We found that the magnitudes of target and distractor information represented in brain activity after the offset of the visual stimuli oscillated in the theta frequency range (4 to 8 Hz). This oscillatory period accords with previous characterizations of rhythmic attentional sampling of continuously visually presented stimuli. Moreover, greater target-distractor theta band phase differences correlated with improved task performance. Our findings show the following: (i) attention separately samples target and distractor representations in sensory memory, (ii) these separately sampled streams of information may mutually inhibit one another, and (iii) target discrimination improves when target and distractor sampling rhythms are desynchronized.

How the human auditory cortex prioritizes relevant information amid concurrent sounds has been a long-standing question in auditory cognitive neuroscience. The present study used auditory steady-state responses to tag the electrocortical response to a tone embedded in concurrent naturalistic sounds, addressing methodological challenges with overlapping auditory streams. Participants endorsing low (high misophonia symptoms) or high misophonia symptoms-a condition with decreased tolerance to specific, typically orofacial, sounds-were recruited. Sounds varied in emotional valence (pleasant, neutral, unpleasant) to investigate how emotional content modulates attentional competition. Orofacial sounds were also included to evaluate how attentional biases are affected by inter-individual sensitivity toward a specific sound category. Affective ratings, alpha-band changes, and pupil dilation were also assessed. Hypothetical models of competition were tested, revealing a facilitation trend in the auditory steady-state responses amplitude when accompanied by pleasant and unpleasant, compared to neutral sounds, regardless of misophonia symptoms. However, auditory steady-state responses was selectively reduced in the high misophonia symptoms but not the high misophonia symptoms group when accompanied by orofacial sounds. Analyses of alpha-band, pupil, and rating data showed that the groups differed primarily in their response to pleasant sounds and orofacial sounds, with the high misophonia symptoms group exhibiting a stronger response to orofacial sounds than the high misophonia symptoms group.

V4, an intermediate visual area in the ventral pathway of the primate visual system, is known to contain neurons selective to visual stimulus attributes of intermediate complexity. Recent studies have shown that macaque V4 is organized into neuronal columns, each tuned to specific natural image features, and topologically arranged across the cortical surface to form functionally specialized domains. Using digital twins of V4 constructed from a large-scale wide-field imaging dataset, we demonstrate that shape- and texture-preferring neurons-previously identified in single-unit studies-are spatially clustered into functional domains. The segregated spatial organization suggests the existence of parallel modules for surface and boundary processing. Unlike artificial neural networks trained for ImageNet classification, which exhibit a strong texture bias, we find that V4 cortical columns and functional domains are more evenly balanced between shape and texture preferences. Finally, we show that computational constraints of feature similarity and retinotopy constraints are necessary and sufficient to explain many observed properties of the organization of the V4 topological map of natural image feature preferences.

Anticipatory EEG signals are characterized by the occurrence of negative slow cortical potentials. This negativity is posed to be enhanced when expecting highly emotional stimuli; however, the specific role attention plays in its generation is unclear, as emotional content is more salient and arousing, and thus recruits higher attentional resources. Here, affective anticipation signals were recorded in 35 participants with EEG, and their brain sources elucidated using multiple sparse priors algorithm. Using a cued-paradigm, the category of a sound being negatively valenced or neutral could be predicted with a 68.2% accuracy. To shift attentional resources away from the emotional content, participants were instructed to listen and respond to a burst of white noise that occurred on 9.1% of trials. Results showed slower reaction times following the aversive cue, yet no difference in EEG amplitude between aversive and neutral anticipation. Response times positively correlated with EEG amplitude-participants with stronger negativity were faster to respond. EEG source reconstruction demonstrated no differences between conditions, and showed activation of areas within the salience network including insula, somatosensory cortex, and thalamus. The current results suggest that anticipatory EEG negativity is an index of attentional resource-allocation during the anticipation period and does not reflect the emotional content of upcoming stimuli.

Context is crucial for interpreting emotional expressions. Behavioral work has consistently demonstrated the powerful impact of emotional context on disambiguating affective expressions within and across modalities. A theoretical framework suggests that context affects vocal emotion perception at all stages of the neural processing hierarchy, including primary auditory cortex. Using functional neuroimaging, we explored how emotional context images influence the perception of subsequently presented vocal emotional morphs taken from fear to pleasure continua. Morphs were embedded in a balanced sequence to enable the investigation of repetition suppression effects, while context images were blocked by emotion. Results revealed that emotionally congruent context-morph pairings enhanced activation in bilateral superior temporal gyri, including bilateral primary auditory cortex. In contrast, emotional incongruence activated bilateral inferior frontal gyri, regions typically associated with domain-general conflict resolution. To determine whether the activation in primary auditory cortex reflects feedforward or feedback processing, we analyzed the effects of context on adaptation to the morphs. Adaptation to vocal emotion was not differentially modulated by context type. Our findings suggest that context information is initially processed independently of the auditory signal and integrated after the adaptation stage, with contextual influences on sensory cortex mediated via feedback mechanisms.

The cardiac oscillatory is found to regulate the brain's functional networks that support cognitive processing and self-awareness. However, whether these associations are specific to certain clinical contexts or general principles remains unclear. The present study investigated oscillatory associations between heart rate variability (HRV) and electroencephalogram (EEG) rhythms to explore the dynamic co-regulatory mechanisms between them when facing tactical motor demands. We performed two studies using a simulated quadrotor UAV operation system, which provided tasks with adjustable skill-challenge balance. Through the variations in motor control prompted by skill proficiency (Study 1) and task demands (Study 2), we conducted some common analyses within the same group of participants, including heartbeat-evoked potentials (HEPs), phase-amplitude coupling (PAC) cross-modal phase-amplitude coupling (xPAC), heart rate variability, and predictive relationships among them. Our results suggested that the association between HRV and PAC can be characterized by the functional relationship between brain and heart, such as xPAC and HEP. As participants became more flexible and adept in motor control, cardiac-brain oscillatory interactions tended to become more coordinated. Within individuals, xPAC robustly tracked PAC across conditions, whereas HRV showed predictive power primarily when skill and task demands were reasonably balanced. Such findings may hold promising implications for enhancing our understanding of performance in neuroergonomics and clinical rehabilitation.

Social touch facilitates our attachment to others, especially early in life, which may be linked to the maturation of parvalbumin interneurons (PVI) in the somatosensory cortex (S1). These neurons respond to social touch, mature in a sensory experience-dependent manner, and influence both somatosensory processing and social behavior in models of Autism Spectrum Disorder. Prairie voles (Microtus ochrogaster) are an ideal rodent model for studying these concepts since they engage in a species-typical social touch called "huddling." In this study, we first found that over development from juvenile to adult, same-sex siblings showed a reduction in huddling and an increase in time investigating one another or behaving apart. Next, we tracked two markers of plasticity indicative of PVI maturation, extracellular perineuronal nets (PNNs) and nuclear transcription factor Myocyte enhancing factor 2C (Mef2c)-across seven developmental timepoints. We found that, while PV expression in S1 was stable by P21, PNNs, and Mef2c continued to shift afterwards, indicating a protracted development. Finally, to determine environmental factors affecting these processes, environmental enrichment between P21 to P28 advanced PVI maturation, and increased conspecific investigation consistent with adult behavior. This developmental mapping provides a particularly salient model to investigate the molecular underpinnings of cortical and social development.

Psychological pain showed stronger predictive power for suicide attempts (SAs) than depression, even in patients with major depressive disorder (MDD). This study aimed to elucidate the compositional architecture of the pain network and quantify the explanatory power of this network versus the reward network in modeling suicide risk mechanisms. Resting-state functional magnetic resonance imaging data from MDD patients with SA, MDD patients without SA, and healthy controls (HCs) were analyzed using graph theoretical analysis. Partial least squares regression was used to assess suicide-related neural alterations in relation to depression and psychological pain. Compared with HCs, MDD patients exhibited reduced nodal centrality in both the reward and pain networks. Within MDD, individuals with SA exhibited changes primarily in the pain network, including a decrease in the betweenness centrality of the right anterior insula. Suicide-related alterations overlapped more with pain avoidance than with depression. Centrality in the right opercular inferior frontal gyrus, left medial superior temporal gyrus, and right anterior insula was associated with pain arousal, feelings, and avoidance, broadening the current understanding of the pain network. These findings extended the conceptualization of the pain network and highlight its pivotal role in suicide risk.