Cerebral cortex最新文献

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.

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.

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.

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.

Traumatic brain injury (TBI) is one of the leading causes of death and disability worldwide. The initial injury initiates a cascade of secondary injury mechanisms, including neuroinflammation and disruption of brain connectivity. In this study, we used the lateral fluid percussion injury model of TBI to investigate the relationship between secondary thalamic inflammation and corticothalamic connectivity disruptions. For this, we followed rats for six months post-injury, during which functional magnetic resonance imaging (fMRI) was conducted under light sedation, as well as diffusion tensor imaging (DTI) and positron emission tomography (PET). PET imaging with [18F]-FEPPA revealed neuroinflammation in the subacute stage in several ipsilateral thalamic nuclei, including the ventral posterior nucleus and lateral nucleus. In the fMRI analysis, we observed initial corticothalamic hypoconnectivity, which partially resolved by six months post-injury. DTI showed persistent increased mean, axial, and radial diffusivity in the ipsilateral thalamic nuclei from two months post-injury. Histological examination confirmed chronic thalamic neuroinflammation and neuronal loss eight months post-TBI. Correlation analyses showed that subacute thalamic neuroinflammation was associated with long-term structural and functional changes. These findings suggest that secondary thalamic inflammation contributes to enduring corticothalamic connectivity disruptions, which may underlie cognitive and sensorimotor deficits observed after TBI.

There has been considerable interest in the neuroanatomical homologue of Broca's region in nonhuman primates, particularly in our phylogenetically closest relative the chimpanzee (Pan troglodytes), to further our understanding of the evolution of language in hominins. The inferior frontal sulcus (ifs) is a critical landmark below which lie language production areas in the language-dominant hemisphere of the human brain, and its homologue is found in the chimpanzee brain. The present study examined the variability in the morphology of the ifs in 73 chimpanzee brains (ie 146 hemispheres). Examination was carried out on surface reconstructions derived from in vivo 3 T magnetic resonance imaging scans, which permitted detailed intra-sulcal assessment. Based on the connections formed by the ifs and adjacent sulci, two frequent and three less frequent morphological types were identified. The average location and spatial variability of the ifs were quantified in the form of spatial surface probability maps. Relationships were also established between specific morphological features of the ifs in the left hemisphere and oro-facial communication abilities, as measured by attention-getting sound production. These findings refine our knowledge of prefrontal sulcal organization in hominids and offer valuable insights into the structural blueprints that supported the emergence of speech in humans.

Our study investigates how language proficiency impacts cognitive processing in the brain. We focused on congenitally and early deaf adults, where individual differences in language access during development significantly influence language proficiency and cognitive function. This variability in language backgrounds and skills allows us to explore the influence of early language experience on the large-scale brain networks that support cognition. We used functional MRI in a group of deaf adults with diverse language backgrounds and a control group of hearing participants. We hypothesized that differences in language skills would modulate neural responses and functional connectivity in task-related networks during the execution of demanding working memory and planning tasks. Our study revealed that differences in language proficiency, independently of language modality (signed or spoken), are positively correlated with neural activity and functional connectivity within the task-positive network during working memory in deaf adults. Furthermore, compared to hearing participants, the deaf group showed distinct patterns of neural activity and connectivity in task-dependent regions in the working memory experiment. Our findings emphasize the profound impact of early environmental experiences on brain responses during cognitive processing. Specifically, they highlight the role of language proficiency in shaping and supporting higher-order cognition.

Theoretical models suggest that loneliness may be linked to abnormal social information processing and reduced emotion regulation capacity; yet these effects have mostly been investigated using self-report methods. Therefore, the current preregistered study examined whether loneliness is associated with objective and subjective markers of bottom-up emotional reactivity and cognitive reappraisal efficiency in a cohort of 150 young adults (18-35 years old) recruited to reflect the distribution of loneliness scores in the Polish population. Participants completed an emotion processing and regulation task with both social and nonsocial stimuli while their electroencephalography activity was recorded. Contrary to the hypotheses, when faced with socio-affective stimuli, lonelier individuals did not exhibit abnormal markers of early sensory processing, late sustained processing, or decreased efficiency in reappraisal use, as indicated by event-related potential markers. Only a weak association between loneliness and an increased P300 response to negative vs. neutral social stimuli was found. This pattern of findings did not align with subjective arousal reports, which suggested a decreased response to negative social stimuli and reduced cognitive reappraisal efficiency in lonelier participants. These results suggest that loneliness is linked to disruptions in emotional self-awareness rather than an abnormal response to socio-affective stimuli.

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.