Brain and Cognition最新文献

Malevolent creativity refers to the ability to generate ideas that cause harm to oneself or others. While previous research has touched on how personality traits influence malevolent creative behavior, the neural mechanisms involved remain underexplored. This study investigated the brain patterns associated with malevolent creative behavior and how these patterns are mediated by dark personality traits (Machiavellianism, narcissism, and psychopathy) and positive traits (internalization, symbolization, and honesty-humility). Our findings revealed that Machiavellianism mediated the relationship between the amplitude of low-frequency fluctuation (ALFF) in the left medial superior frontal gyrus (mSFG), pallidum (PAL), and middle temporal gyrus (MTG) and malevolent creative behavior, particularly in actions like hurting people or playing tricks. Psychopathy similarly mediated the link between the ALFF in the right orbital middle frontal gyrus (oMFG), right mSFG, left PAL, and left MTG and malevolent creative behavior. Additionally, Machiavellianism negatively mediated the relationship between the fractional ALFF (fALFF) of the left parahippocampal gyrus (PHG) and hurting people, as well as between the fALFF of the left inferior occipital gyrus (IOG) and playing tricks. The ALFF in the left mSFG and left MTG predicted playing tricks but also negatively predicted internalization and honesty-humility, which in turn reduced engagement in playing tricks. Finally, the fALFF of the left IOG negatively predicted playing tricks and positively predicted internalization, which again decreased playing tricks. These findings highlight the complex interaction between brain activity, personality traits, and malevolent creative behavior, offering a potential path for targeted interventions and further research into this interesting phenomenon.

This study examined behavioral, electrophysiological (EEG), and autonomic responses to stress during the preparation and speech stages of five discourses among 26 adults. Participants underwent an increasingly stressful job-interview based on a modified Trier Social Stress Test, receiving feedback from an evaluative board. Findings showed increased RTs, higher cardiovascular responses [Pulse Volume Amplitude (PVA), and Heart Rate Variability (HRV)] and generalized increases in EEG frequency bands (delta, theta, alpha, beta, gamma) during the speech compared to the preparation stage. The rising emotional salience of the discourses induced a negativity bias and extensive low-frequency band activation (delta and theta) across the scalp in response to emotional demands. High-frequency bands exhibited a plateau effect, indicating less cognitive involvement as the discourses progressed. In our opinion, a possible interpretation is that this effect could be due to habituation mechanisms or coping strategies. Autonomic results revealed significant variations in PVA, with higher levels during the first discourse preparation, indicating substantial cognitive effort. Despite increased emotional arousal, participants managed stress effectively, as evidenced by increased HRV during the speech stage. Overall, during progressively increasing ecological psychosocial stress, individuals displayed marked emotional reactions in terms of low-frequency bands and cardiovascular indices, particularly during the first speeches rather than the preparation stages of an interview.

The purpose of this study was to investigate anticipatory functions in temporal cognition, identifying the presence of proactive brain processing specifically preceding a time discrimination task. To this aim, two discriminative response tasks (DRTs) were employed: a feature DRT and a temporal (T-DRT). While the F-DRT required discrimination among different geometrical shapes, the T-DRT required discrimination among different stimulus durations. Specifically, this study investigated the role of premotor and prefrontal cortices, and sensory visual areas in preparatory activity preceding time-processing by electroencephalographic methods and analyzing the event-related potential (ERP). ERP components associated with motor (the BP), cognitive (the pN), and sensory readiness (the vN) were analyzed on 21 participants completing the two DRTs. The results support the involvement of all considered brain areas in temporal cognition but extend this information by indicating that these areas can be engaged during the preparation phase before the stimulus is delivered. Furthermore, the T-DRT requires strong anticipatory activity in the PFC likely serving as a moderator of upcoming motor responses. Finally, visual areas were greatly engaged in the early phase of sensory readiness of the T-DRT probably to create top-down low-level representations of imminent events to facilitate perception.

Most recent accounts highlight the importance of two aspects of cognition in the implicit understanding of the physical world: semantic knowledge (the ability to recognize, categorize, and relate concepts) and mechanical knowledge (the capability to comprehend how things mechanically work). However, how the human brain may integrate these cognitive processes remains largely unexplored. Here, we use functional magnetic resonance imaging to investigate this integration employing a novel free-viewing task. Participants viewed images depicting object-tool pairs that were either mechanically consistent (e.g., nail - steel hammer) or mechanically inconsistent (e.g., scarf - steel hammer). These pairs were situated on a metal plate atop a table, with a stripped electrical cable in contact with the plate that could be plugged in or out from the electrical line, rendering the tools either electrified or not. Task-based functional connectivity revealed an interplay among specific left-brain regions - the middle temporal (MTG), inferior frontal (IFG), and supramarginal (SMG) gyri - during the processing of mechanical actions and physics principles, associating the activity of these areas with mechanical knowledge (SMG) and object-related semantic knowledge (MTG). Notably, the IFG was active during both types of processing, suggesting a critical role of this region in multi-modal information integration. These findings support the most recent integrated neurocognitive models of physical understanding, deepening our comprehension of how we make sense of the physical world.

Mixed Transcortical Aphasia (MTA) is an infrequent aphasic syndrome, characterized by poor comprehension and production in oral language abilities and poor performance in written language abilities. However, individuals with MTA typically retain the ability to repeat. Our patient, a woman who suffered from a left hemisphere ischemic stroke involving perisylvian areas, presented with repetition preserved for words, non-words, sentences and numbers, together with marginally preserved reading abilities. Given the peculiarity of her linguistic profile, we employed recently developed lesion-based approaches for probabilistic estimation of white matter disconnections to reveal which white matter tracts are likely to be related to her preserved linguistic abilities. Our analysis revealed that while the left arcuate fasciculus (AF)-a tract commonly associated with repetition-was partially affected, its posterior and long branches were estimated to be disconnected, whereas the anterior branch remained intact. This disconnection pattern may explain the pattern of preserved repetition abilities observed in this MTA patient.

Persistent cognitive fatigue (CF) is the most reported symptom in Post-Acute Sequelae of SARS-CoV-2 Infection (PASC), but little is known about its underlying neural basis. This pilot study examined fMRI brain activation patterns during a fatiguing task in those with and without PASC. We hypothesized that individuals with PASC would show changes in CF-related brain activation within fatigue network. Participants were 10 adults with PASC and persistent CF and 10 age- and gender-matched healthy controls. The 2-back working memory task was used during fMRI to induce CF. Patients with PASC reported greater CF, as measured using a Visual Analogue Scale of Fatigue (VAS-F), throughout the task. The relationship of brain activation in the fatigue network to increased CF during the fatiguing task did not differ between groups. There were, however, more areas inside and outside the fatigue network that were activated in the PASC group as reported CF increased. The relationship between brain activation and scores on the 2-back did differ between groups, with the PASC group showing more frontal activation. Findings suggest that individuals with PASC and CF may need to exert greater mental effort during demanding cognitive tasks, reflected in recruitment of a broader network of brain regions.

The present study focused on the influence of training methods and task difficulty on event-related potentials (ERPs) at early and later visual perceptual learning (VPL) on a coherent motion identification task. Sixty participants were randomly divided into four groups for training with an adaptive stimulus (staircase group) and three constant stimuli (moderate, easy and difficult intensity groups). Visual performance improved in the staircase and moderate training groups but not in the easy or difficult training groups. ERP results revealed a decreased P1 amplitude in all groups. Additionally, staircase training increased the frontal P2 amplitude; accordingly, moderate constant stimulus training reduced the frontal P2 amplitude and increased the frontal N2 amplitude. Importantly, the change in frontal P2 amplitude was correlated with improved performance, indicating the involvement of cortices responsible for higher-order cognitive processes in VPL. Additionally, the difference in frontal P2 amplitude changes suggests the modulation of training methods (adaptive and consistent) on the role of attention in VPL. Furthermore, although behavior changes were not observed, the brains in the easy and difficult groups still presented different ERP changes. In summary, the results provide electrophysiological evidence for the modulation of training methods and task difficulty in VPL-related neuroplasticity.

Differences in the brain sensitivity to color responses may cause significant differences in the latency and amplitude of the electroencephalographic (EEG) component. This paper investigated the electroencephalography features of binocular color fusion and binocular color rivalry when watching stereoscopic three-dimensional (3D) displays. EEG experiments were conducted on a conventional 3D display platform. Eight subjects were involved to analyze differences in the event-related potential (ERP) and power spectrum when the brain perceived binocular color fusion and binocular color rivalry. Results show that: 1) the latencies of ERP components N1 and P2 of binocular color fusion were shorter than that of binocular color rivalry, 2) the amplitudes of the ERP components P2 and P3 of binocular color fusion were greater than that that of color rivalry, and 3) the left hemisphere was dominant for binocular color rivalry while the right hemisphere was greater involved in binocular color fusion. These results indicate that during the initial and mid-term cognitive processing, the brain response to binocular color fusion is faster than binocular color rivalry. Both binocular color fusion and rivalry involve visual post-processing, but binocular color fusion requires a greater allocation of neural resources. Power spectrum analysis revealed the cerebral lateralization in binocular color fusion and rivalry, it suggested that the way the brain processes this binocular input can have effects on its function.

Human experiences are inherently shaped by individual perspectives, leading to diverse interpretations of the same events. However, shared activities, such as communal film watching or sports viewing, underscore the dual nature of these experiences: collective joy arises through social interactions, while individual emotional responses are influenced by personal preferences. The neural mechanisms underlying this interplay between shared and idiosyncratic experiences, particularly in the context of reward processing, remain insufficiently explored. In this study, we investigated the neural basis of both communal enjoyment and individual anticipatory responses during short video viewing. Using functional MRI, we measured brain activity in participants as they watched 90 short videos and provided ratings of their reward expectations and experienced pleasure. By integrating intersubject correlation (ISC) and individual-specific analyses, we identified shared and unique neural activity patterns. Our findings reveal that synchronized activity within the default mode network (DMN) and reward-related regions underlies shared experiences of collective pleasure. In contrast, distinct activations in the frontal cortex and caudate nucleus were associated with personal preferences and reward anticipation, highlighting a neural dichotomy between communal enjoyment and individualized reward processing during digital media engagement.

Background: About half of MCI patients experience semantic deficits, which may predict progression to Alzheimer's disease (AD). The neural basis of these deficits in MCI is not well understood. This study aimed to examine the relationship between semantic memory performance and cortical thickness in MCI patients.

Methods: Using FreeSurfer, T1-weighted MRI scans were analyzed from MCI patients with (MCIsem+) and without (MCIsem-) semantic deficits. Correlation analyses across all participants, including healthy controls, examined the link between semantic memory and cortical thickness, controlling for age and education. Group comparisons of cortical thickness were also conducted between MCIsem+ and MCIsem- groups.

Results: Significant correlations emerged between semantic memory performance and cortical thickness in the left medial temporal lobe, right temporal pole, and bilateral frontal regions-areas involved in central semantic and executive processes. Additionally, MCIsem + patients showed reduced cortical thickness in frontal, parietal, and occipital areas compared to MCIsem- patients.

Conclusion: Semantic memory performance in MCI patients is associated with structural differences in regions supporting both central and executive aspects of semantic processing. Given that MCIsem + patients may face higher risk of AD progression, longitudinal studies should investigate these cortical markers' predictive value.