Dreaming: Cognitive processes during cortical activation and high afferent thresholds.

Activity, modulation and role of basal forebrain cholinergic neurons innervating the cerebral cortex

The human thalamus projects nerve fibers to all cortical regions and propagates epileptic activity. However, opportunities to directly record thalamic and cortical neural activities simultaneously are extremely limited and their electrophysiological interactions remain largely unexplored. Therefore, in this study, we recruited six patients who underwent awake craniotomy with opened lateral ventricles. The electrodes were placed on the thalamic surface over the ventricular wall and brain surface around the central sulcus. Electrical stimulation was applied to each electrode to record the evoked responses. Furthermore, we performed time-frequency and statistical analyses to investigate the cortical responses induced by electrical stimulation. High gamma activity was elicited in the cerebral cortex following thalamic stimulation. However, regarding frequency bands, the cortical spectral response induced by thalamic stimulation (TCSR) showed power increases in more restricted bands at approximately 100 Hz compared with the cortical spectral response induced by cortical stimulation (CCSR). In contrast, more electrodes in CCSRs showed a power decrease after the power increase than those in TCSRs. Finally, compared with the cortex, thalamic projections evoked localized neural activity in the cortex. Adjusting stimulus intensity and comparison with deep thalamic electrode stimulation will further clarify thalamocortical linkages.

The purpose of the present study is to explore how the emotionalized expression of news content in the posttruth era affects the cognitive processing of the audiences. One news that was text-written with two different expression types (emotional expression vs. neutral expression) was adopted as an experiment material in the study, and changes in cortical activity during news reporting reading tasks were examined with electroencephalograms, sampled from nine sites and four channels and analyzed with weighted phase lag index (wPLI) based on brain functional connectivity (FC) method. The results show that emotional discourses caused a stronger cortical brain activity and more robust brain FC (beta oscillations); besides, reading emotionalized expression consumed more attention resources but fewer cognitive resources, which may impede further rational thinking of the audiences.

Congenital mirror movement disorder (CMMD) is characterized by unintended, nonsuppressible, homologous mirroring activity contralateral to the movement on the intended side of the body. In healthy controls, unilateral movements are accompanied with predominantly contralateral cortical activity, whereas in CMMD, in line with the abnormal behavior, bilateral cortical activity is observed for unilateral motor tasks. However, task-related activities in subcortical structures, which are known to play critical roles in motor actions, have not been investigated in CMMD previously. We investigated the functional activation patterns of the motor components in CMMD patients. By using linkage analysis and exome sequencing, common mutations were revealed in seven affected individuals from the same family. Next, using functional magnetic resonance imaging (fMRI) we investigated cortical and subcortical activity during manual motor actions in two right-handed affected brothers and sex, age, education, and socioeconomically matched healthy individuals. Genetic analyses revealed heterozygous RAD51 c.401C>T mutation which cosegregated with the phenotype in two affected members of the family. Consistent with previous literature, our fMRI results on these two affected individuals showed that mirror movements were closely related to abnormal cortical activity in M1 and SMA during unimanual movements. Furthermore, we have found previously unknown abnormal task-related activity in subcortical structures. Specifically, we have found increased and bilateral activity during unimanual movements in thalamus, striatum, and globus pallidus in CMMD patients. These findings reveal further neural correlates of CMMD, and may guide our understanding of the critical roles of subcortical structures for unimanual movements in healthy individuals.

Owing to the complexity of human behaviors in risk situation and the harsh physical environment of underground mine, current researches on coalmine virtual environment have paid little attention on modeling human risk behaviors. Based on Artificial Life method, an intelligent virtual miner agent model was proposed to yield better understandings of human factors in emergency situation and to assist risk behaviors analysis in underground coalmine. The virtual miner agent is a comprehensive model of 3D virtual human and combines perceptual, behavioral, internal states and cognitive modules. And then, behavioral model of virtual miner was introduced in detail. Behaviors of virtual miner are constructed by a set of parameterized basic actions and are controlled by personalized action selection mechanism, which incorporate miners' cognitive processes and internal state characteristics to explore human behavioral mechanism of risk accidents. The preliminary results of application case show the effectiveness of our method to simulate human risk behaviors in coalmine virtual environment.

Tinnitus affects 10-15% of adults globally, yet there are still no effective treatments for this major health condition. Repetitive transcranial magnetic stimulation (rTMS), a noninvasive neuromodulation technique, allows modulation of pathologically altered functional activities to promote symptom remission. However, its efficacy critically depends on the selection of stimulation targets, and substantial interindividual variability has been observed in clinical trials. Here, we aimed to identify potential target regions that are causally involved in alleviating distinct functional abnormalities using the digital twin brain (DTB). A cohort of 89 participants was used to characterize whole-brain neural activity patterns. Multimodal neuroimaging data were used to develop the tinnitus-specific DTB and to generate causal response maps based on more than 1.64 million virtual stimulations. Whole-brain gene expression data were further integrated to examine the neurobiological plausibility of the DTB-derived causal response maps. Finally, we validated the predictive capacity of such response maps using an independent rTMS dataset. We identified two aberrant brain states that emerged sequentially with disease progression, predominantly overlapping with the somatomotor and default mode networks, respectively. DTB-derived causal response maps revealed that the modulation of sensory and cognitive states requires stimulation of distinct, functionally specialized regions. Specifically, parieto-occipital regions play a crucial role in sensory modulation, while the dorsolateral prefrontal cortex exerts a causal influence on cognitive modulation. Moreover, these causal response maps correlate with the expression of tinnitus risk genes. By incorporating individual connectivity profiles of target regions, DTB-derived causal response maps accurately predicted rTMS effects on both sensory state (r > 0.85, Ppermutation < 0.01) and cognitive state (r > 0.78, Ppermutation < 0.05). Particularly, the predictive capacity exhibited a state-specific nature. This work suggests that brain functional alterations in tinnitus evolve with disease progression, and DTB has the potential to predict rTMS effects on distinct brain states, thereby informing more precise and targeted noninvasive brain stimulation interventions for tinnitus. Trial registered with https://www.chictr.org.cn/indexEN.html , Explore the mechanism of repetitive transcranial magnetic stimulation intervention in tinnitus based on multi-modal functional magnetic resonance imaging (ChiCTR2100047989), Submitted June 2021, First Patient Enrolled July 2021.

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This paper presents the results of studying the brain activations of 30 engineering students when using three different design concept generation techniques: brainstorming, morphological analysis, and TRIZ. Changes in students’ brain activation in the prefrontal cortex were measured using functional near-infrared spectroscopy. The results are based on the area under the curve analysis of oxygenated hemodynamic response as well as an assessment of functional connectivity using Pearson’s correlation to compare students’ cognitive brain activations using these three different ideation techniques. The results indicate that brainstorming and morphological analysis demand more cognitive activation across the prefrontal cortex (PFC) compared to TRIZ. The highest cognitive activation when brainstorming and using morphological analysis is in the right dorsolateral PFC (DLPFC) and ventrolateral PFC. These regions are associated with divergent thinking and ill-defined problem-solving. TRIZ produces more cognitive activation in the left DLPFC. This region is associated with convergent thinking and making judgments. Morphological analysis and TRIZ also enable greater coordination (i.e., synchronized activation) between brain regions. These findings offer new evidence that structured techniques like TRIZ reduce cognitive activation, change patterns of activation and increase coordination between regions in the brain.

The presence of respiration-locked sensory cortical activity has been documented in various mammalian species in recent years, including cognitively-relevant gamma oscillations (30-80 Hz). This work builds on previous evidence suggesting that respiration has a direct influence on oscillatory activity in human sensory, motor and association cortical areas. The entrainment of cortical activity patterns by respiratory phase suggests a direct influence of respiration on cognitive processing, which represents a possible neuronal mechanism behind the well-documented but unexplained effects of respiratory exercises on emotional and cognitive functions. We explore possible interpretation of those findings in the context of the cinematic view of cognition, in particular cortical phase transitions. In addition to traditional Fourier-based correlational analysis of cortical signals, we introduce Hilbert analysis, which allows to monitor rapid phase synchronization-desynchronization transitions. Our results support the hypothesis that respiration-locked cortical activity is linked to phase transitions in the cortex, measured by discontinuities of the instantaneous phase of the analytic signal determined by the Hilbert transform. Taken together, these findings suggest that respiration acts as master clock exerting a subtle but unfailing synchronizing influence on the temporal organization of dynamic cortical activity patterns and the cognitive processes they control.

The cross-sectional decontextualization afflicting contemporary neuroscience—attributing to "the brain" what is the province of the whole individual—is mirrored by an evolutionary decontextualization exceptionalizing consciousness. The living state is characterized by cognitive processes at all scales and levels of organization. Many can be associated with dual information sources that "speak" a "language" of behavior-in-context. Shifting, tunable, global broadcasts analogous to consciousness, albeit far slower—wound healing, tumor control, immune function, gene expression, etc.—have emerged through repeated evolutionary exaptation of the crosstalk and noise inherent to all information transmission. These broadcasts recruit "unconscious" cognitive modules into shifting arrays as needed to meet the threats and opportunities that confront all organisms across multiple frames of reference. The development is straightforward, based on the powerful necessary conditions imposed by the asymptotic limit theorems of communication theory, in the same sense that the Central Limit Theorem constrains sums of stochastic variates. Recognition of information as a form of free energy instantiated by physical processes that consume free energy permits analogs to phase transition and nonequilibrium thermodynamic arguments, leading to "dynamic regression models" useful for data analysis.

Background: There is a need to monitor brain resuscitation during CPR. Furthermore, 10% of CA survivors report cognitive activity and 2-3% report consciousness during CPR. Methods: Using data from a prospective study (AWARE-II) with bimodal brain monitoring during CPR (EEG, [Massimo] and regional cerebral oxygenation [rSO2 normal 60-80%]) using cerebral oximetry [Nonin]), we sought to identify EEG rhythms, their progression over time, and underlying rSO2 thresholds. Inclusion criteria: In hospital CA, ≥ 18 years. Raw EEG data were captured as images (1/second) during CPR pauses, while rSO2 was captured continuously. Results: 38 patients were recruited; mean age 69±16 with duration of CPR (10-60 mins). We captured 362 EEG images. 91 (25%) were artifacts. Among the 271 interpretable images, there were 13 EEG rhythms placed into 6 groups based on their association with normal/near normal, seizures, coma, absence of cortical activity as follows: Group 1 (Non-epileptogenic): Theta, Delta, Alpha, Group 2 (Epileptogenic/Spike and Wave): Generalized Rhythmic Delta Activity (GRDA) + Spike (S), Delta + S, Theta + S, Burst Suppression with GRDA + S, Group 3 (Flat-line): Marked Voltage Attenuation (MVA), Group 4 (Coma State): Burst Suppression (w/ GRDA, Delta, and/or Theta), Group 5: GRDA, Group 6: Generalized Periodic Discharges (GPD). MVA/absence of activity was observed throughout CPR time and across all rSO2 ranges. Normal/near normal (non-epileptogenic) including alpha rhythms (which to our knowledge is described for the first time), and epileptogenic rhythms were observed with rSO2&gt;30% Conclusions: While unclear whether non-epileptogenic rhythms are associated with transient periods of ROSC, however real-time bimodal brain monitoring provides insights regarding brain resuscitation and its dynamic interaction with patient factors. While ischemia may cause epileptogenic activity, there are periods of normal/near-normal cortical activity despite prolonged CPR &gt;45-60 mins. A minimal threshold of brain oxygen delivery (rSO2&gt;30%) may be required for cortical activity. These data raise questions regarding assumptions of irreversible brain damage with prolonged CPR, as well as the possibility of consciousness and cognitive activity during CPR.

During preparation for action, the presentation of loud acoustic stimuli (LAS) can trigger movements at very short latencies in a phenomenon called the StartReact effect. It was initially proposed that a special, separate subcortical mechanism that bypasses slower cortical areas could be involved. We sought to examine the evidence for a separate mechanism against the alternative that responses to LAS can be explained by a combination of stimulus intensity effects and preparatory states. To investigate whether cortically mediated preparatory processes are involved in mediating reactions to LAS, we used an auditory reaction task where we manipulated the preparation level within each trial by altering the conditional probability of the imperative stimulus. We contrasted responses to non-intense tones and LAS and examined whether cortical activation and subcortical excitability and motor responses were influenced by preparation levels. Increases in preparation levels were marked by gradual reductions in reaction time (RT) coupled with increases in cortical activation and subcortical excitability - at both condition and trial levels. Interestingly, changes in cortical activation influenced motor and auditory but not visual areas - highlighting the widespread yet selective nature of preparation. RTs were shorter to LAS than tones, but the overall pattern of preparation level effects was the same for both stimuli. Collectively, the results demonstrate that LAS responses are indeed shaped by cortically mediated preparatory processes. The concurrent changes observed in brain and behavior with increasing preparation reinforce the notion that preparation is marked by evolving brain states which shape the motor system for action.

Purpose of reviewSynesthesia is an extraordinary perceptual phenomenon, in which individuals experience unusual percepts elicited by the activation of an unrelated sensory modality or by a cognitive process. Emotional reactions are commonly associated. The condition prompted philosophical debates on the nature of perception and impacted the course of art history. It recently generated a considerable interest among neuroscientists, but its clinical significance apparently remains underevaluated. This review focuses on the recent studies regarding variants of color synesthesia, the commonest form of the condition.Recent findingsSynesthesia is commonly classified as developmental and acquired. Developmental forms predispose to changes in primary sensory processing and cognitive functions, usually with better performances in certain aspects and worse in others, and to heightened creativity. Acquired forms of synesthesia commonly arise from drug ingestion or neurological disorders, including thalamic lesions and sensory deprivation (e.g., blindness). Cerebral exploration using structural and functional imaging has demonstrated distinct patterns in cortical activation and brain connectivity for controls and synesthetes. Artworks of affected painters are most illustrative of the nature of synesthetic experiences.SummaryResults of the recent investigations on synesthesia offered a remarkable insight into the mechanisms of perception, emotion and consciousness, and deserve attention both from neuroscientists and from clinicians.

Dreaming: Cognitive processes during cortical activation and high afferent thresholds.

Neural oscillations are fundamental for brain function and govern various cognitive processes. Recent functional magnetic resonance imaging advances offer the opportunity to study frequency-specific properties of blood-oxygen-level-dependent oscillations at multiple frequency bands. However, most have focused on spontaneous brain activity in the resting state, leaving a gap in direct evidence regarding the specific activations of cognitive tasks across different frequency bands. We aim to address this gap by exploring the role of blood-oxygen-level-dependent oscillations across multiple frequency bands in cognitive processes. We used task-functional magnetic resonance imaging data of 339 healthy young adults from the Human Connectome Project to map the activation patterns of performing seven cognitive tasks at multiple frequency bands (ie slow-1 to slow-6). Our findings revealed that different frequency bands are associated with distinct task-activation patterns. Specifically, slow-1/2/3 oscillations primarily contribute to local sensory information processing, while slow-4 is crucial for various fundamental cognitive functions. Slow-5 is involved in cognitive processes that require greater memory load, integrated cognitive processing, and attention maintenance. This underscores the importance of analyzing a broad frequency range to capture the full spectrum of cognitive function, highlighting the diverse roles of different frequency bands in brain activity, shedding light on the underlying mechanism of brain–behavior associations.