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BackgroundAlzheimer's disease (AD) is the most common form of dementia, progressively impairing cognitive abilities. While neuroimaging studies have revealed functional abnormalities in AD, how these relate to aberrant neuronal circuit mechanisms remains unclear. Using magnetoencephalography imaging we documented abnormal local neural synchrony patterns in patients with AD. To identify global abnormal biophysical mechanisms underlying the spatial and spectral electrophysiological patterns in AD, we estimated the parameters of a biophysical spectral graph model (SGM).MethodsSGM is an analytic neural mass model that describes how long-range fiber projections in the brain mediate the excitatory and inhibitory activity of local neuronal subpopulations. Unlike other coupled neuronal mass models, the SGM is linear, available in closed-form, and parameterized by a small set of biophysical interpretable global parameters. This facilitates their rapid and unambiguous inference which we performed here on a well-characterized clinical population of patients with AD (N = 88, age = 62.73 +/- 8.64 years) and a cohort of age-matched controls (N = 88, age = 65.07 +/- 9.92 years).ResultsPatients with AD showed significantly elevated long-range excitatory neuronal time scales, local excitatory neuronal time scales and local inhibitory neural synaptic strength. The long-range excitatory time scale had a larger effect size, compared to local excitatory time scale and inhibitory synaptic strength and contributed highest for the accurate classification of patients with AD from controls. Furthermore, increased long-range time scale was associated with greater deficits in global cognition.ConclusionsThese results demonstrate that long-range excitatory time scale of neuronal activity, despite being a global measure, is a key determinant in the local spectral signatures and cognition in the human brain, and how it might be a parsimonious factor underlying altered neuronal activity in AD. Our findings provide new insights into mechanistic links between abnormal local spectral signatures and global connectivity measures in AD.

Technological tools, like electroencephalography and functional near‐infrared spectroscopy, have deepened our understanding of cortical regions involved in balance control. In this systematic literature review, we aimed to identify the prevalent cortical areas activated during balance tasks with specific motor or cognitive demands. Our search strategy encompassed terms related to balance control and cortical activity, yielding 2250 results across five databases. After screening, 67 relevant articles were included in the review. Results indicated that manipulations of visual and/or somatosensory information led to prevalent activity in the parietal, frontal and temporal regions; manipulations of the support base led to prevalent activity of the parietal and frontal regions; both balance‐cognitive dual‐tasking and reactive responses to extrinsic perturbations led to prevalent activity in the frontal and central regions. These findings deepen our comprehension of the cortical regions activated to manage the complex demands of maintaining body balance in the performance of tasks posing specific requirements. By understanding these cortical activation patterns, researchers and clinicians can develop targeted interventions for balance‐related disorders. [ABSTRACT FROM AUTHOR]

Introduction: This systematic review explores the use of neurophysiological measurements to study emotional responses to cosmetic products. The aim is to evaluate existing literature on these measurements in cosmetics, identify the main findings, highlight methodological challenges, and propose new guidelines for future research. Method: A systematic search focusing on neurophysiological measures to determine emotions induced by different cosmetic products was carried out in accordance with PRISMA guidelines. Results: A total of 33 articles identified with the EBSCO database met the inclusion criteria. In all, 10 different measurement tools were used in these articles to assess the emotional effects of cosmetic products. Discussion: This review emphasizes the complexity of interactions between cosmetics and emotional responses. It underscores the importance of future research with a more holistic approach that couples several physiological measurements. Among them, electrophysiological brain activity shows potential for enhancing understanding of emotional responses related to cosmetic products. Frontal asymmetry, particularly in the alpha frequency band, was often use and frequently linked to positive emotional states, although conflicting evidence exists. Additionally, cardiac activity, specifically the LF/HF ratio, emerges as a promising marker for differentiating between different cosmetic products. However, methodological heterogeneity, present challenges for replicability, generalizability, and complicate data interpretation. [ABSTRACT FROM AUTHOR]

There is no relationship more vital than the one a child shares with their primary caregivers early in development. Yet many children worldwide are raised in settings that lack the warmth, connection, and stimulation provided by a responsive primary caregiver. In this study, we used data from the Bucharest Early Intervention Project (BEIP), a longitudinal study of institutionally‐reared and family‐reared children, to test how caregiving quality during infancy is associated with average EEG power over the first 3.5 years of life in alpha, beta, and theta frequency bands, and associations with later executive function (EF) at age 8 years. The sample comprised 189 children (129 institutionally‐reared; 60 family‐reared) who contributed data on observed caregiving quality during infancy (baseline; average age of 22 months), resting EEG power at baseline, 30, and 42 months, and performance‐based data on a series of EF tasks at 8 years. Using Bayesian estimation, observed caregiving quality at baseline was marginally linked with higher average alpha and beta power, and lower theta power, from baseline to 42 months. In turn, higher average beta power and lower average theta power were marginally associated with higher EF at 8 years. In indirect effects models, higher caregiving quality at baseline was associated with higher EF at 8 years, with a marginal indirect effect through average theta power from baseline to 42 months. Variation in the quality of the early caregiving environment may be associated with later executive function, which is partially underpinned by individual differences in brain activity during early childhood. Research Highlights: Examined associations between caregiving quality during infancy, brain activity during early childhood, and executive function during mid‐childhood in sample of never‐institutionalized and institutionally‐reared children.Significant associations between higher quality caregiving during infancy and higher executive function during middle childhood.Marginal associations between caregiving quality during infancy and brain activity during early childhood.Marginal associations between brain activity during early childhood and executive function during mid‐childhood. [ABSTRACT FROM AUTHOR]

Athletes heavily rely on visual perception for performance. This study delves into electroencephalographic (EEG) brain activity among gymnastics, soccer, and esports athletes during resting states with eyes closed (REC) and open (REO) and compares differences in EEG alpha power from REC to REO (∆ EC-EO Alpha) across athlete groups. Forty-two female participants, including 14 from each athletic discipline, underwent two 5-minute EEG recordings, first during REC and then during REO conditions. Absolute EEG power was analyzed for delta (δ), theta (θ), alpha (α), and beta (β) frequency bands across various brain regions, and ∆ EC-EO Alpha values were computed. During REC, soccer players exhibited heightened α power at the midline frontopolar (Fpz) and β power at the midline occipital (Oz). Conversely, during REO, soccer players displayed increased δ power at Fpz and midline frontal (Fz) and reduced α power at the midline central (Cz) compared to gymnasts, along with elevated θ power at Fpz. Esports athletes demonstrated higher δ power and decreased α power at Fpz and Cz compared to gymnasts. Gymnasts exhibited distinct cortical activation patterns characterized by lower ∆ EC-EO Alpha at multiple electrode sites. These findings highlight sport-specific cortical activation patterns linked to visual attention among athletes. Understanding these neural adaptations could refine training methods and enhance performance outcomes in sports. [ABSTRACT FROM AUTHOR]

A brain-computer interface (BCI) is a transformative technology that enables users to control external devices or communicate solely through the analysis of their brain activity. One promising aspect of BCIs is the utilization of steady-state visually evoked potentials (SSVEPs), a neurophysiological response in the brain that synchronizes with repetitive visual stimuli. This paper introduces a novel approach known as the trans-subject feature fusion approach (TFA), designed to improve SSVEP-based BCIs. This methodology streamlines data pre-processing, creates invariant SSVEP templates, and simplifies calibration, addressing key challenges that have hindered BCI adoption. By doing so, the main aim is to contribute to the advancement of BCIs, making them more accessible and efficient for a range of applications, from assistive technologies to healthcare, ultimately enhancing users' communication, and control capabilities. [ABSTRACT FROM AUTHOR]

AbstractWith an aging population, detecting cognitive dysfunction at an early stage is important. However, no current neurophysiological assessments examine brain activity status in community-dwelling older adults. Therefore, this study aimed to characterize event-related potential (ERP) during go/no-go tasks in older adults with potential cognitive impairment living in the community. The participants were 34 young adults and 46 older adults. They underwent a go/no-go task to measure ERP. The older adults were divided into two groups for analysis based on the results of the Japanese version of the Montreal Cognitive Assessment (MoCA-J): cognitively normal and cognitively impaired. N2 latency was significantly delayed in the cognitively impaired group compared to the cognitively normal and younger groups. Furthermore, the younger group exhibited a significant increase in P3 amplitude and shorter latency compared to both older adult groups. The results of the correlation analysis between ERP and neuropsychological test scores showed that N2 latency correlated with neuropsychological test scores. The results also suggested that receiver operating characteristic curve analysis can measure cognitive function. These results indicated that N2 latency reflected potential cognitive dysfunction in community-dwelling older adults. Furthermore, P3 amplitude may be useful in detecting age-related inhibitory function decline. [ABSTRACT FROM AUTHOR]

One of the critical challenges in brain-computer interfaces is the classification of brain activities through the analysis of EEG signals. This paper seeks to improve the efficacy of deep learning-based rehabilitation systems, aiming to deliver superior services for individuals with physical disabilities. The research introduces the time distributed long short-term memory (TD-LSTM) framework, which incorporates an LSTM and a time distributed approach to classify brain activities. Learning in TD-LSTM is achieved by uncovering time-dependent semantic dependencies within EEG signals over time. By extracting all discriminative and relevant spatiotemporal dependencies via TD-LSTM, valuable information on different time steps in each sequence has been obtained. Time distributed approach shortens the input time series, making learning from long time series sequences easier, and the learning process of complex temporal and spatial dependencies in time series multi-channel EEG signals becomes more efficient. The main contributions in this paper can be outlined as follows: (1) implementation of brain activity binary classification of motor imagery/execution tasks using time distributed approach via RNN network for the first time, (2) evaluation of the performance and generalizability of the proposed method on four benchmark datasets, (3) dual-purpose classification which providing an efficient ways for classifying both types of motor imagery/execution brain activity. The experimental results show that the proposed method performs well compared to several baseline research works. [ABSTRACT FROM AUTHOR]

The phenomenon of near death and dying experiences has been both of popular interest and of scientific speculation. However, the reality of mental perception at the point of death is currently a subjective experience and has not been formally evaluated. While postmortem gene expression, even in humans, has been evaluated, restoration of postmortem brain activity has heretofore only been attempted in animal models, at the molecular and cellular levels. Meanwhile, progress has been made to translate brain activity of living humans into speech and images. This paper proposes two inter-related thought experiments. First, assuming progress and refinement of the technology of translating human brain activity into interpretable speech and images, can an objective analysis of death experiences be obtained by utilizing these technologies on dying humans? Second, can human brain function be revived postmortem and, if so, can the relevant technologies be utilized for communication with (recently) deceased individuals? In this paper, these questions are considered and possible implications explored. [ABSTRACT FROM AUTHOR]

A quality therapeutic alliance, as a component of a successful psychotherapeutic process, provides a trusting relationship and effective collaboration between psychotherapist and client. This narrative review examines research that explores the relationship between psychophysiological measures of psychotherapy participants and their subjective perceptions of alliance quality. The results of 10 empirical articles, selected after a systematic literature search, are presented within several paragraphs. Each of the paragraphs analyzes and discusses studies using measures of the same human body system, followed by recommendations for further research in the conclusion. Thus, as a result of the analysis of the selected sources, the perceived quality of the alliance showed a positive relationship with the synchronization of brain activity indices, heart rate variability, heart rate, skin electrical activity, and breathing patterns between the participants in the process. However, the only study examined the contribution of participants' individual heart rate variability indices, which showed a relationship only for the client alliance. At the same time, the structure of interrelationships between alliance components and psychophysiological parameters differed depending on the number of participants: in dyadic, in family, in the presence of a supervisor or a second therapist. Recorded changes in physiological parameters may reflect both the patterns of participants' cognitive processes and their affective states - and together add to the understanding of the dynamic process of establishing and experiencing an alliance between participants in a psychotherapy session. Future research should unify the research design, continue to clarify the role of interpersonal synchronization in alliance experience, pay attention to differences in couples and group psychotherapy, and examine multiple psychophysiological variables simultaneously using a multilevel approach.

Abstract Athletes heavily rely on visual perception for performance. This study delves into electroencephalographic (EEG) brain activity among gymnastics, soccer, and esports athletes during resting states with eyes closed (REC) and open (REO) and compares differences in EEG alpha power from REC to REO (∆ EC-EO Alpha) across athlete groups. Forty-two female participants, including 14 from each athletic discipline, underwent two 5-minute EEG recordings, first during REC and then during REO conditions. Absolute EEG power was analyzed for delta (δ), theta (θ), alpha (α), and beta (β) frequency bands across various brain regions, and ∆ EC-EO Alpha values were computed. During REC, soccer players exhibited heightened α power at the midline frontopolar (Fpz) and β power at the midline occipital (Oz). Conversely, during REO, soccer players displayed increased δ power at Fpz and midline frontal (Fz) and reduced α power at the midline central (Cz) compared to gymnasts, along with elevated θ power at Fpz. Esports athletes demonstrated higher δ power and decreased α power at Fpz and Cz compared to gymnasts. Gymnasts exhibited distinct cortical activation patterns characterized by lower ∆ EC-EO Alpha at multiple electrode sites. These findings highlight sport-specific cortical activation patterns linked to visual attention among athletes. Understanding these neural adaptations could refine training methods and enhance performance outcomes in sports.

Background: Yoga breathing influences cortical activity and, hence, cortico-efferent sensory activity. Previously, slow yoga breathing influenced the components of mid-latency auditory evoked potentials. Objective: The present study aimed to compare middle latency auditory evoked potentials (MLAEPs) recorded during (i) High-frequency yoga breathing (HFYB), (ii) Breath awareness (BAW), and (iii) Quiet rest (QR) as a control in experienced yoga practitioners. Materials and Methods: The MLAEPs were recorded before, during, and after the practice of HFYB compared to an equal duration of BAW and QR in 22 university students whose ages ranged from 18 to 28 years, recorded from the vertex referenced to linked earlobes and the ground electrode on forehead. Results: The peak amplitude of the Pa wave was significantly increased during HFYB compared to before HFYB (repeated measures ANOVA, post hoc analysis with least significant difference, P < 0.05). During BAW, the peak amplitude of the Na wave was significantly increased compared to before BAW (P < 0.05). During QR, the peak latency of “Pa” and “Nb” waves was significantly increased compared to before QR (P < 0.01). Conclusions: The findings suggest that changes in MLAEPs during HFYB, BAW, and QR were different and distinct. Both interventional sessions appear to increase the recruitment of neural resources in the primary auditory cortex, whereas QR appears to slow transmission within the thalamic reticular projection to the cortex. Generalizing the findings is restricted by the sample being confined to male experienced practitioners of yoga breathing.

Reconstructing visual stimulus information from evoked brain activity is a significant task of visual decoding of the human brain. However, due to the limited size of published functional magnetic resonance imaging (fMRI) datasets, it is difficult to adequately train a complex network with a large number of parameters. Furthermore, the dimensions of fMRI data in existing datasets are extremely high, and the signal-to-noise ratio of the data is relatively low. To address these issues, we design an fMRI-based visual decoding framework that incorporates additional self-supervised training on the encoder and decoder to alleviate the problem of insufficient model training due to limited datasets. Furthermore, we propose a iterative Two Part and Two Stage learning method involving a teacher (supervised)-student (self-supervised) setup and encoder-decoder asynchronous updates strategy. This approach allows the encoder and decoder to mutually reinforce and iteratively update each other under the guidance of a teacher model. The analysis of the ablation experiments demonstrates that the proposed framework can effectively improve the reconstruction accuracy. The experimental results show that the proposed method achieves better visual reconstruction from evoked brain activity of the human brain and that its reconstruction accuracy is superior to that of existing methods. [ABSTRACT FROM AUTHOR]

Introduction: Asthma is a serious disease that affects not only the respiratory system but also the brain by decreasing oxygen saturation. Despite the numerous neuroimaging studies that have shed light on the effect of asthma on brain volume, there is still a need for new studies to evaluate brain volume in asthmatic patients. Aim: To evaluate the Grey Matter Volume (GMV) of the brain in asthmatic patients using Magnetic Resonance Imaging images (MRI) to detect possible changes. Materials and Methods: This is an observational analytic case-control study carried out at Al Amal Hospital in Khartoum State, Sudan, between January 2020 and October 2022. The study included 100 adult participants (50 asthmatic patients and 50 healthy controls) using MRI and automatic brain segmentation through a software program (BrainSuite). Data were analysed using Statistical Package for Social Science (SPSS) software, version 25.0 (IBM SPSS Inc., Chicago, IL), and Microsoft Excel 2013. An independent sample T-test was used to compare the mean of the measurements between controls and asthmatics. Frequencies, means, and standard deviations were taken. A p-value of 0.05 or less was accepted as statistically significant. Results: Out of all participants, 50 were asthmatics and 50 were controls. The mean age of asthmatics was (31±8.53) years and of controls was 32±8.49 years. The mean Grey Matter Volume (GMV) of the asthmatic patients was 575.93 cm3±71.46 SD and of controls was 569.55 cm3±73.77 SD. There were no statistically significant differences between the groups depending on the GMV of asthmatic and control participants (p>0.05). The mean GMV in asthmatic males was 355.50 cm3±53.26 SD and in females 321.65 cm3±32.72 SD, while in control males it was 367.63 cm3±45.77 SD and in females 318.03 cm3±34.16 SD. GMV showed significant statistical differences between asthmatic males and females (p0.05). Asthma disease does not result in noticeable changes in GMV in either male or female brains.

Introduction: Asthma is a serious disease that affects not only the respiratory system but also the brain by decreasing oxygen saturation. Despite the numerous neuroimaging studies that have shed light on the effect of asthma on brain volume, there is still a need for new studies to evaluate brain volume in asthmatic patients. Aim: To evaluate the Grey Matter Volume (GMV) of the brain in asthmatic patients using Magnetic Resonance Imaging (MRI) images to detect possible changes. Materials and Methods: This is an observational analytic casecontrol study carried out at Al Amal Hospital in Khartoum State, Sudan, between January 2020 and October 2022. The study included 100 adult participants (50 asthmatic patients and 50 healthy controls) using MRI and automatic brain segmentation through a software program (BrainSuite). Data were analysed using Statistical Package for Social Science (SPSS) software, version 25.0 (IBM SPSS Inc., Chicago, IL), and Microsoft Excel 2013. An independent sample T-test was used to compare the mean of the measurements between controls and asthmatics. Frequencies, means, and standard deviations were taken. A p-value of 0.05 or less was accepted as statistically significant. Results: Out of all participants, 50 were asthmatics and 50 were controls. The mean age of asthmatics was (31±8.53) years and of controls was 32 ± 8.49 years. The mean Grey Matter Volume (GMV) of the asthmatic patients was 575.93 cm³ ±71.46 SD and of controls was 569.55 cm³ ±73.77 SD. There were no statistically significant differences between the groups depending on the GMV of asthmatic and control participants (p>0.05). The mean GMV in asthmatic males was 355.50 cm³ ±53.26 SD and in females 321.65 cm³ ±32.72 SD, while in control males it was 367.63 cm³ ±45.77 SD and in females 318.03 cm³ ±34.16 SD. GMV showed significant statistical differences between asthmatic males and females (p<0.05). Conclusion: There were no statistically significant differences between the groups depending on the GMV of asthmatic and control participants (p>0.05). Asthma disease does not result in noticeable changes in GMV in either male or female brains. [ABSTRACT FROM AUTHOR]

Dynamical systems on networks typically involve several dynamical processes evolving at different timescales. For instance, in Alzheimer’s disease, the spread of toxic protein throughout the brain not only disrupts neuronal activity but is also influenced by neuronal activity itself, establishing a feedback loop between the fast neuronal activity and the slow protein spreading. Motivated by the case of Alzheimer’s disease, we study the multiple-timescale dynamics of a heterodimer spreading process on an adaptive network of Kuramoto oscillators. Using a minimal two-node model, we establish that heterogeneous oscillatory activity facilitates toxic outbreaks and induces symmetry breaking in the spreading patterns. We then extend the model formulation to larger networks and perform numerical simulations of the slow-fast dynamics on common network motifs and on the brain connectome. The simulations corroborate the findings from the minimal model, underscoring the significance of multiple-timescale dynamics in the modeling of neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

K1-format kickboxing is a widely followed combat sport that requires intense physical exercise. However, research into the body's response to this type of combat is sparse. This study aims to assess the alterations in hormone levels and brain activity in elite kickboxers following an actual K1 bout and compare these changes with those observed in a control group engaged in a simulated fight exercise with a punchbag. The study included 100 male professional kickboxers, randomly divided into two groups: an experimental group (K1 fight) and a control group (simulated fight with a punchbag). Blood samples were obtained before and after exercise to evaluate testosterone (T) and cortisol concentrations (C). Concurrently, brain activity was recorded using quantitative electroencephalography (QEEG). After the activity in the experimental group mean testosterone level slightly, non-significantly decreased from 13.7 nmol/l to 12.4 nmol/l, while mean cortisol significantly (p < 0.001) increased from 313 to 570 nmol/l. In the control group after the exertion against a punchbag mean cortisol significantly (p < 0.001) increased from 334 to 452 nmol/l and testosterone increased non-significantly, from 15.1 to 16.3 nmol/l. In both groups, the testosterone/cortisol ratio (T/C ratio) showed significantly lower levels after the intervention (p < 0.001 and p < 0.032) in the experimental and control group respectively. The comparison of groups after exercise revealed significantly higher cortisol levels (experimental group x = 570 nmol/l; control group x = 452 nmol/l) and a significantly lower T/C ratio (experimental group x = 2.7; control group x = 3.9), (p = 0.001) in the experimental group. Significantly higher brain activity was found in selected leads after a bout (experimental group). Furthermore, in the experimental group, significant associations of weak to moderate strength were found between hormone fluctuations and selected areas of brain activity (p < 0.05). K1-format kickboxing induces a stress response, evident in the sharp changes in cortisol and testosterone levels. A notable observation was the inverse direction of changes in both hormones. Brain activity analysis indicated the potential influence of raised cortisol concentrations on specific brain areas. This study augments our understanding of the physiological responses during K1 kickboxing bouts and may inform the future evolution of this sport. [ABSTRACT FROM AUTHOR]

Dental drilling sounds can induce anxiety in some patients. This study aimed to use functional magnetic resonance imaging (fMRI) to assess the relationship between dental fear and auditory stimuli. Thirty-four right-handed individuals (21 women and 13 men; average age, 31.2 years) were selected. The level of dental fear was assessed using the dental fear survey (DFS). Based on a threshold DFS score > 52, participants were categorized into two groups: dental fear (DF) group (n = 12) and control group (n = 22). Two types of stimuli were presented in a single session: dental and neutral sounds. Cerebral activation during the presentation of these sounds was evaluated using contrast-enhanced blood oxygenation level-dependent fMRI. In the DF group, dental sounds induced significantly stronger activation in the left inferior frontal gyrus and left caudate nucleus (one-sample t test, P < 0.001). In contrast, in the control group, significantly stronger activation was observed in the bilateral Heschl's gyri and left middle frontal gyrus (one-sample t test, P < 0.001). Additionally, a two-sample t test revealed that dental sounds induced a significantly stronger activation in the left caudate nucleus in the DF group than in the control group (P < 0.005). These findings suggest that the cerebral activation pattern in individuals with DF differs from that in controls. Increased activation of subcortical regions may be associated with sound memory during dental treatment. [ABSTRACT FROM AUTHOR]

Osteopathic manipulative treatment (OMT) is a hands-on therapy aiming to achieve the global homeostasis of the patient. OMT focuses on treating the somatic dysfunctions characterized by tissue modifications, body asymmetry, and range-of-motion restrictions. The benefits related to OMT are thought to be associated with the interconnectedness of the body's systems and the inherent capacity for self-healing. However, whether OMT can influence brain activity, and, consequently, neurophysiological responses is an open research question. Our research investigates the literature to identify the effects of OMT on brain activity. The main purpose of the research question is: can OMT influence brain activity and consequently neurophysiological responses? A scoping review was conducted, searching the following databases: PubMed, Google Scholar, and OSTEOMED.DR (Osteopathic Medical Digital Repository), Scopus, Web of Science (WoS), and Science Direct. The initial search returned 114 articles, and after removing duplicates, 69 were considered eligible to be included in the final sample. In the end, eight studies (six randomized controlled trials, one pilot study, and one cross-over study) were finally included and analyzed in this review. In conclusion, OMT seems to have a role in influencing functional changes in brain activity in healthy individuals and even more in patients with chronic musculoskeletal pain. However, further RCT studies are needed to confirm these findings. Registration protocol: CRD42024525390. [ABSTRACT FROM AUTHOR]

The human brain is composed of multiple, discrete, functionally specialized regions that are interconnected to form large-scale distributed networks. Using advanced brain-imaging methods and machine-learning analytical approaches, recent studies have demonstrated that regional brain activity during the performance of various cognitive tasks can be accurately predicted from patterns of task-independent brain connectivity. In this review article, we first present evidence for the predictability of brain activity from structural connectivity (i.e., white matter connections) and functional connectivity (i.e., temporally synchronized task-free activations). We then discuss the implications of such predictions to clinical populations, such as patients diagnosed with psychiatric disorders or neurologic diseases, and to the study of brain–behavior associations. We conclude that connectivity may serve as an infrastructure that dictates brain activity, and we pinpoint several open questions and directions for future research. [ABSTRACT FROM AUTHOR]

This study presents a trial analysis that uses brain activity information obtained from mice to detect rheumatoid arthritis (RA) in its presymptomatic stages. Specifically, we confirmed that F759 mice, serving as a mouse model of RA that is dependent on the inflammatory cytokine IL-6, and healthy wild-type mice can be classified on the basis of brain activity information. We clarified which brain regions are useful for the presymptomatic detection of RA. We introduced a matrix completion-based approach to handle missing brain activity information to perform the aforementioned analysis. In addition, we implemented a canonical correlation-based method capable of analyzing the relationship between various types of brain activity information. This method allowed us to accurately classify F759 and wild-type mice, thereby identifying essential features, including crucial brain regions, for the presymptomatic detection of RA. Our experiment obtained brain activity information from 15 F759 and 10 wild-type mice and analyzed the acquired data. By employing four types of classifiers, our experimental results show that the thalamus and periaqueductal gray are effective for the classification task. Furthermore, we confirmed that classification performance was maximized when seven brain regions were used, excluding the electromyogram and nucleus accumbens. [ABSTRACT FROM AUTHOR]

The plans of international space agencies to return to the Moon and explore deep space, including Mars, highlight the challenges of human adaptation and stress the need for a thorough analysis of the factors that facilitate, limit and modify human performance under extreme environments. This study investigates the influence of partial gravity on behavioural (error rate and reaction time) and neuronal parameters (event-related potentials) through parabolic flights. Brain cortical activity was assessed using EEG from 18 participants who solved a neurocognitive task, consisting of a mental arithmetic task and an auditory oddball paradigm, during Earth (1G), Lunar (0.16G + 0.25G) and Martian gravity (0.38G + 0.5G) for 15 consecutive parabolas. Data shows higher electrocortical activity in Earth gravity compared to Lunar and Martian gravity in the parietal lobe. No differences in participants' performance were found among the gravity levels. Event-related potentials displayed gravity-dependent variations, though limited stimuli recording suggests caution in interpretation. Data suggests a threshold between Earth and Martian gravity within the different gravities responsible for physiological changes, but it seems to vary greatly between individuals. The altered neuronal communication could be explained with a model developed by Kohn and Ritzmann in 2018. The increasing intracranial pressure in weightlessness changes the properties of the cell membrane of neurons and leads to a depolarisation of the resting membrane potential. The findings underscore the individuality of physiological changes in response to gravity alterations, signalling the need for further investigations in future studies. [ABSTRACT FROM AUTHOR]

The effects of mindfulness-based interventions on performance have recently been investigated, with several studies assessing changes in brain activity. The aim of the current systematic review was to identify the neural correlates of mindfulness practice that enhance performance. We completed searches on Scopus, PubMed, EBSCO, and Web of Science in February 2020. Peer-reviewed studies that implemented mindfulness-based interventions or compared groups of mindfulness meditators with non-practitioners and measured the neural activity underpinning performance were eligible. The quality of the studies and evidence was assessed with the Cochrane risk of bias tool and the GRADE system. Of the 1836 records identified, 20 published articles (925 participants) were found, including 8 experimental, 5 quasi-experimental, and 7 cross-sectional studies. None of the studies were rated as having a low risk of bias. The quality of evidence was graded to be low and very low. The main finding that emerged was the potential enhancing effect of mindfulness practice on performance monitoring abilities, which are highly important to detect and adjust to errors. Overall findings did not provide a robust evidence for neural correlates of mindfulness practice aimed to enhance performance, highlighting the need for future research. This study is registered on PROSPERO, number CRD42020185471. [ABSTRACT FROM AUTHOR]

Herein, we briefly review the role of nicotinic acetylcholine receptors in regulating important brain activity by controlled release of acetylcholine from subcortical neuron groups, focusing on a microscopic viewpoint and considering the nonlinear dynamics of biological macromolecules associated with neuron activity and how they give rise to advanced brain functions of brain. [ABSTRACT FROM AUTHOR]

IntroductionThis systematic review explores the use of neurophysiological measurements to study emotional responses to cosmetic products. The aim is to evaluate existing literature on these measurements in cosmetics, identify the main findings, highlight methodological challenges, and propose new guidelines for future research.MethodA systematic search focusing on neurophysiological measures to determine emotions induced by different cosmetic products was carried out in accordance with PRISMA guidelines.ResultsA total of 33 articles identified with the EBSCO database met the inclusion criteria. In all, 10 different measurement tools were used in these articles to assess the emotional effects of cosmetic products.DiscussionThis review emphasizes the complexity of interactions between cosmetics and emotional responses. It underscores the importance of future research with a more holistic approach that couples several physiological measurements. Among them, electrophysiological brain activity shows potential for enhancing understanding of emotional responses related to cosmetic products. Frontal asymmetry, particularly in the alpha frequency band, was often use and frequently linked to positive emotional states, although conflicting evidence exists. Additionally, cardiac activity, specifically the LF/HF ratio, emerges as a promising marker for differentiating between different cosmetic products. However, methodological heterogeneity, present challenges for replicability, generalizability, and complicate data interpretation.

Background: Clinical and translational research has identified deficits in the dopaminergic neurotransmission in the striatum in Alzheimer's disease (AD) and this could be related to the pathophysiology of psychiatric symptoms appearing even at early stages of the pathology. Hypothesis: We hypothesized that AD pathology in the hippocampus may influence dopaminergic neurotransmission even in the absence of AD-related lesion in the mesostriatal circuit. Methods: We chemogenetically manipulated the activity of hippocampal neurons and astrocytes in wild-type and hemizygous TgF344-AD (Tg) rats, an animal model of AD pathology. We assessed the brain-wide functional output of this manipulation using in vivo Single Photon Emission Computed Tomography to measure cerebral blood flow and D2/3 receptor binding, in response to acute (3 mg kg-1 i.p.) and chronic (0.015 mg/ml in drinking water, 28 days) stimulation of neurons or astrocytes with clozapine N-oxide. We also assessed the effects of the chronic chemogenetic manipulations on D2 receptor density, low or high aggregated forms of amyloid Aβ40 and Aβ42, astrocytes and microglial reactivity, and the capacity of astrocytes and microglia to surround and phagocytize Aβ both locally and in the striatum. Results: We showed that acute and chronic neuronal and astrocytic stimulation induces widespread effects on the brain regional activation pattern, notably with an inhibition of striatal activation. In the Tg rats, both these effects were blunted. Chemogenetic stimulation in the hippocampus increased microglial density and its capacity to limit AD pathology, whereas these effects were absent in the striatum perhaps as a consequence of the altered connectivity between the hippocampus and the striatum. Conclusions: Our work suggests that hippocampal AD pathology may alter mesostriatal signalling and induce widespread alterations of brain activity. Neuronal and astrocytic activation may induce a protective, Aβ-limiting phenotype of microglia, which surrounds Aβ plaques and limits Αβ concentration more efficiently.

Objectives: The prevalence of multiple health hazards in various industries is on the rise, with noise and heat being common harmful factors in industrial environments in Iran. This study aimed to examine the immediate effects of simultaneous exposure to thermal stress and noise on human brain waves and perceived workload.Methods: Seventy-two students (36 men and 36 women) participated voluntarily in this study. Participants were subjected to varying levels of noise exposure, including four noise levels and heat stress (three levels of Wet Bulb Globe Temperature) for 30 minutes each. EEG recordings were conducted for 10 minutes, with participants allowed a 30-minute rest period between each test condition.Results: The combined exposure to noise and heat at two high levels (SPL95+WBGT34 and SPL95+WBGT29) resulted in a significant increase in perceived mental workload compared to the baseline state (P

Abstract Background Alzheimer’s disease (AD) is the most common form of dementia, progressively impairing cognitive abilities. While neuroimaging studies have revealed functional abnormalities in AD, how these relate to aberrant neuronal circuit mechanisms remains unclear. Using magnetoencephalography imaging we documented abnormal local neural synchrony patterns in patients with AD. To identify global abnormal biophysical mechanisms underlying the spatial and spectral electrophysiological patterns in AD, we estimated the parameters of a biophysical spectral graph model (SGM). Methods SGM is an analytic neural mass model that describes how long-range fiber projections in the brain mediate the excitatory and inhibitory activity of local neuronal subpopulations. Unlike other coupled neuronal mass models, the SGM is linear, available in closed-form, and parameterized by a small set of biophysical interpretable global parameters. This facilitates their rapid and unambiguous inference which we performed here on a well-characterized clinical population of patients with AD (N = 88, age = 62.73 +/- 8.64 years) and a cohort of age-matched controls (N = 88, age = 65.07 +/- 9.92 years). Results Patients with AD showed significantly elevated long-range excitatory neuronal time scales, local excitatory neuronal time scales and local inhibitory neural synaptic strength. The long-range excitatory time scale had a larger effect size, compared to local excitatory time scale and inhibitory synaptic strength and contributed highest for the accurate classification of patients with AD from controls. Furthermore, increased long-range time scale was associated with greater deficits in global cognition. Conclusions These results demonstrate that long-range excitatory time scale of neuronal activity, despite being a global measure, is a key determinant in the local spectral signatures and cognition in the human brain, and how it might be a parsimonious factor underlying altered neuronal activity in AD. Our findings provide new insights into mechanistic links between abnormal local spectral signatures and global connectivity measures in AD.

Complex actions require more cognitive and motor control than simple ones. Literature shows that to face complexity, the brain must make a compromise between available resources usually giving priority to motor control. However, literature has minimally explored the effect of the motor response complexity on brain processing associated with cognitive tasks. Consequently, it is unknown whether carrying out a cognitive task requiring motor responses of increasing complexity could reduce cognitive processing keeping stable motor control. Therefore, this study aims to investigate possible modulations exerted by increasing motor response complexity in a cognitive task on brain processing. To this aim, we analyzed the event-related potentials and behavioral responses during a cognitive task with increasing complexity of the required motor response (keypress, reaching and stepping). Results showed the increasing motor complexity enhances early visual and attentional processing (P1 and N1 components) but reduces the late post-perceptual cognitive control (P3 component). Additionally, we found a component following the P3 which was specific for stimuli requiring a response. This component, labeled N750, increased amplitude along with the response motor complexity. Behaviorally, response accuracy was not affected by complexity. Results indicated that in cognitive tasks stimulus processing is affected by the complexity of the motor response. Complex responses require a greater investment of early perceptual and attentional resources, but at late phases of processing, cognitive resources are less available in favor of motor resources. This confirms the idea of the motor-priority cognitive-motor trade-off of the brain.

AbstractRepeated stress is associated with an increased risk of developing psychiatric illnesses such as post-traumatic stress disorder (PTSD), which is more common in women, yet the neurobiology behind this sex difference is unknown. Habituation to repeated stress is impaired in PTSD, and recent preclinical studies have shown that female rats do not habituate as fully as male rats to repeated stress, which leads to impairments in cognition and sleep. Further research should examine sex differences after repeated stress in other relevant measures, such as body temperature and neural activity. In this study, we analyzed core body temperature and EEG power spectra in adult male and female rats during restraint, as well as during sleep transitions following stress. We found that core body temperature of male rats habituated to repeated restraint more fully than female rats. Additionally, we found that females had a higher average beta band power than males on both days of restraint, indicating higher levels of arousal. Lastly, we observed that females had lower delta band power than males during sleep transitions on Day 1 of restraint, however, females demonstrated higher delta band power than males by Day 5 of restraint. This suggests that it may take females longer to initiate sleep recovery compared with males. These findings indicate that there are differences in the physiological and neural processes of males and females after repeated stress. Understanding the way that the stress response is regulated in both sexes can provide insight into individualized treatment for stress-related disorders.

We explore the stability and dynamic properties of a hierarchical, linearized, and analytic spectral graph model for neural oscillations that integrates the structural wiring of the brain. Previously, we have shown that this model can accurately capture the frequency spectra and the spatial patterns of the alpha and beta frequency bands obtained from magnetoencephalography recordings without regionally varying parameters. Here, we show that this macroscopic model based on long-range excitatory connections exhibits dynamic oscillations with a frequency in the alpha band even without any oscillations implemented at the mesoscopic level. We show that depending on the parameters, the model can exhibit combinations of damped oscillations, limit cycles, or unstable oscillations. We determined bounds on model parameters that ensure stability of the oscillations simulated by the model. Finally, we estimated time-varying model parameters to capture the temporal fluctuations in magnetoencephalography activity. We show that a dynamic spectral graph modeling framework with a parsimonious set of biophysically interpretable model parameters can thereby be employed to capture oscillatory fluctuations observed in electrophysiological data in various brain states and diseases.

Despite rapid advances in sensor development and technological miniaturization, it remains challenging to non-invasively record small-amplitude electrophysiological signals from an animal in its natural environment. Many advances in ecophysiology and biologging have arisen through sleep studies, which rely on detecting small signals over multiple days and minimal disruption of natural animal behavior. This paper describes the development of a surface-mounted system that has allowed novel electrophysiological recordings of sleep in wild marine mammals. We discuss our iterative design process by providing sensor-comparison data, detailed technical illustrations, and material recommendations. We describe the system’s performance over multiple days in 12 freely moving northern elephant seals (Mirounga angustirostris) sleeping on land and in water in captivity and the wild. We leverage advances in signal processing by applying independent components analysis and inertial motion sensor calibrations to maximize signal quality across large (> 10 gigabyte), multi-day datasets. Our study adds to the suite of biologging tools available to scientists seeking to understand the physiology and behavior of wild animals in the context in which they evolved.

In metropolitan areas worldwide, abandoned properties are prevalent, prompting a need for small urban green spaces (SUGS) to meet the growing demand. Understanding residents' preferences and perceptions of transformed spaces is vital for effective urban design. This study delves into residents' preferences and perceptions regarding the transformation of such spaces into SUGS and their impact on psychological well-being. By examining how these preferences and perceived health benefits shape the value of transformed spaces, the research aims to inform effective urban design strategies. The participants underwent visual stimulation, with psychological reactions recorded through Electroencephalogram (EEG) readings and assessed via Questionnaire. Machine learning techniques analyzed EEG sub-band data, achieving an average accuracy of 92.8% when comparing leftover and designed spaces. Results revealed that different types of transformed spaces provoke distinct physiological and preference responses. Specifically, viewing SUGS was associated with significant changes in gamma wave power, suggesting a correlation between enhanced gamma activity and increased feelings of empathy. Moreover, participants also reported enhanced comfort, relaxation, and overall mood, and a strong preference for SUGS over untransformed spaces, emphasizing the value placed on these areas for their health benefits. This research highlights the positive impact of even SUGS on mental health, using EEG data to assess emotional states triggered by urban spaces. The study concludes with a call for further research to investigate the long-term benefits of SUGS on well-being, alongside an exploration of the gamma band as a neural marker for emotional restoration in urban green spaces. This research highlights the crucial role of urban design in fostering psychological well-being through the strategic development of green spaces, suggesting a paradigm shift toward more inclusive, health-promoting urban environments. [ABSTRACT FROM AUTHOR]

• The effects of driving experience and attentional control on the perception of driving scenes were experimentally investigated through the event-related potential P300. • Both driving experience and attentional control elevated the performance of target perception. • Greater improvement in the latency of the P300 and reaction time for the perceptual target was observed in the driving experience than attentional control. • The greater contribution of experience in aiding the performance of visual attention in scene perception rather than attentional control. Numerous types of objects in traffic scenes are visually perceived and recognized to determine safe driving maneuvers. Visual attention is the most important brain function for selecting and processing necessary information in the driving environment. To perceive various targets during driving, attentional resources are distributed across the entire scene. Direct control of attention through instruction and/or cues, which result in tuning the resolution of attentional areas, aids the performance of attention. Additionally, the fixation point distribution of an experienced driver becomes wider and tends to shift to the location where the vehicle will be in the next few seconds. Electroencephalography studies have shown distinct characteristics in the attention-related event-related potential known as P300 between experienced and beginner drivers. These findings suggest that experience allows for the optimization of visual attention and direct attentional control. However, it remains unknown how they differ in altering visual attention performance and related brain activity. This study experimentally investigated the effects of driving experience and attentional control on the perception of driving scenes using the event-related potential P300. Our results showed a greater improvement in P300 latency for perceptual targets with driving experience rather than an increase in visual attention intensity. The results suggest that experience enhances visual attention more effectively than attentional control in terms of acceleration of brain signal processing. [ABSTRACT FROM AUTHOR]

Introduction: Neurological consequences of preterm infants born to mothers with gestational diabetes mellitus (GDM) are unclear. In this pilot study, we investigated the effect of GDM on brain activity in very preterm infants. Methods: Preterm infants <32 gestational weeks of mothers with GDM compared to gestational age- and sex-matched controls born between 2011 and 2018 were included. Amplitude-integrated electroencephalography (aEEG) was assessed for total maturation and individual component scores according to Burdjalov and colleagues, the dominating visual background, and the presence of sleep-wake cycles per hour in the first 72 h of life and weekly at days 7, 14, 21, and 28. Results: We included 47 infants of mothers with GDM and 94 control infants. Both the aEEG total maturation score and its individual component scores, as well as the percentage of continuous background pattern, increased equally during the first 4 weeks after birth in both groups. GDM-exposed infants showed a slightly but significantly higher number of sleep-wake cycles per hour. Conclusion: We found normal maturation of brain activity in the first 4 weeks after birth in very preterm infants born to mothers with GDM, not differing from a very preterm control group. The higher number of sleep-wake cycles per hour in GDM-exposed infants could indicate transiently enhanced maturation. Further studies on brain activity and brain development in very preterm infants of mothers with GDM are needed to validate our results. [ABSTRACT FROM AUTHOR]

Objectives: The prevalence of multiple health hazards in various industries is on the rise, with noise and heat being common harmful factors in industrial environments in Iran. This study aimed to examine the immediate effects of simultaneous exposure to thermal stress and noise on human brain waves and perceived workload. Methods: Seventy-two students (36 men and 36 women) participated voluntarily in this study. Participants were subjected to varying levels of noise exposure, including four noise levels and heat stress (three levels of Wet Bulb Globe Temperature) for 30 minutes each. EEG recordings were conducted for 10 minutes, with participants allowed a 30-minute rest period between each test condition. Results: The combined exposure to noise and heat at two high levels (SPL95+WBGT34 and SPL95+WBGT29) resulted in a significant increase in perceived mental workload compared to the baseline state (P<0.05). EEG analysis indicated a decrease in absolute alpha power in the two high-level conditions compared to the baseline (t<0), while absolute beta power showed a significant increase in the two highlevel conditions compared to the baseline mode (SPL45+WBGT22). Conclusion: The study demonstrated that simultaneous exposure to noise and heat, leading to an elevated perceived mental workload, was associated with decreased absolute alpha power and increased absolute beta power in the frontal and occipital regions. These findings suggest that these changes serve as reliable indicators of cognitive and physiological performance. [ABSTRACT FROM AUTHOR]

Currently, there is limited evidence regarding various neurophysiological responses to strength exercise and the influence of the adopted practice schedule. This study aimed to assess the acute systemic effects of snatch training bouts, employing different motor learning models, on skill efficiency, electric brain activity (EEG), heart rate variability (HRV), and perceived exertion as well as mental demand in novices. In a within-subject design, sixteen highly active males (mean age: 23.13 ± 2.09 years) randomly performed snatch learning bouts consisting of 36 trials using repetitive learning (RL), contextual interference (blocked, CIb; and serial, CIs), and differential learning (DL) models. Spontaneous resting EEG and HRV activities were recorded at PRE and POST training bouts while measuring heart rate. Perceived exertion and mental demand were assessed immediately after, and barbell kinematics were recorded during three power snatch trials performed following the POST measurement. The results showed increases in alpha, beta, and gamma frequencies from pre- to post-training bouts in the majority of the tested brain regions (p values ranging from < 0.0001 to 0.02). The CIb model exhibited increased frequencies in more regions. Resting time domain HRV parameters were altered following the snatch bouts, with increased HR (p < 0.001) and decreased RR interval (p < 0.001), SDNN, and RMSSD (p values ranging from < 0.0001 to 0.02). DL showed more pronounced pulse-related changes (p = 0.01). Significant changes in HRV frequency domain parameters were observed, with a significant increase in LFn (p = 0.03) and a decrease in HFn (p = 0.001) registered only in the DL model. Elevated HR zones (> HR zone 3) were more dominant in the DL model during the snatch bouts (effect size = 0.5). Similarly, the DL model tended to exhibit higher perceived physical (effect size = 0.5) and mental exertions (effect size = 0.6). Despite the highest psycho-physiological response, the DL group showed one of the fewest significant EEG changes. There was no significant advantage of one learning model over the other in terms of technical efficiency. These findings offer preliminary support for the acute neurophysiological benefits of coordination-strength-based exercise in novices, particularly when employing a DL model. The advantages of combining EEG and HRV measurements for comprehensive monitoring and understanding of potential adaptations are also highlighted. However, further studies encompassing a broader range of coordination-strength-based exercises are warranted to corroborate these observations. [ABSTRACT FROM AUTHOR]

Background: Orthodontic treatment is often accompanied by discomfort and pain in patients, which are believed to be a result of orthodontic tooth displacement caused by the mechanical forces exerted by the orthodontic appliances on the periodontal tissues. These lead to change blood oxygen level dependent response in related brain regions. Objective: This systematic review aims to assess the impact of experimental orthodontic tooth displacement on alterations in central nervous system activation assessed by tasked based and resting state fMRI. Materials and Methods: A literature search was conducted using online databases, following PRISMA guidelines and the PICO framework. Selected studies utilized magnetic resonance imaging to examine the brain activity changes in healthy participants after the insertion of orthodontic appliances. Results: The initial database screening resulted in 791 studies. Of these, 234 were duplicates and 547 were deemed irrelevant considering the inclusion and exclusion criteria. Of the ten remaining potential relevant studies, two were excluded during full‐text screening. Eight prospective articles were eligible for further analysis. The included studies provided evidence of the intricate interplay between orthodontic treatment, pain perception, and brain function. All of the participants in the included studies employed orthodontic separators in short‐term experiments to induce tooth displacement during the early stage of orthodontic treatment. Alterations in brain activation were observed in brain regions, functional connectivity and brain networks, predominantly affecting regions implicated in nociception (thalamus, insula), emotion (insula, frontal areas), and cognition (frontal areas, cerebellum, default mode network). Conclusions: The results suggest that orthodontic treatment influences beyond the pain matrix and affects other brain regions including the limbic system. Furthermore, understanding the orthodontically induced brain activation can aid in development of targeted pain management strategies that do not adversely affect orthodontic tooth movement. Due to the moderate to serious risk of bias and the heterogeneity among the included studies, further clinical trials on this subject are recommended. [ABSTRACT FROM AUTHOR]

Resilience-based interventions can improve positive psychosocial resources for vulnerable children. However, it is unclear about the neural mechanism of how psychosocial resources are enhanced by resilience-based intervention in AIDS orphans. To fill this gap, we designed a six-week resilience-based intervention for twenty AIDS orphans raised in institutions (age:15.75 ± 1.97). The efficacy of the intervention was evaluated by employing a pre- and post-intervention study design, with multilevel estimations at the baseline and completion phase, and a follow-up behavioral estimation 8 months afterward. We found that AIDS orphans' optimism about the future (p =.01) and perceived teachers' support (p =.02) increased significantly after resilience-based intervention, these gains were still maintained after 8-months. Moreover, the changes in optimism about future could be predicted by both intervention-caused alterations and baselines of the amplitude of low frequency fluctuations in putamen; the changes in perceived teachers' support could be predicted by both intervention-caused alterations and baselines of the amplitude of low frequency fluctuations in postcentral gyrus. These findings indicated the potential intervention-specific neural changes in AIDS orphans along with the improvement of psychosocial resource. Our study contributed to optimizing the person-centered treatment and advancing the precision mental health of vulnerable children. [ABSTRACT FROM AUTHOR]

In this paper, we discuss how the clustering analysis technique can be applied to analyze functional magnetic resonance imaging (fMRI) time-series data in the context of glioblastoma (GBM), a highly heterogeneous brain tumor. The precise characterization of GBM is challenging and requires advanced analytical approaches. We have synthesized the existing literature to provide an overview of how clustering algorithms can help identify unique patterns within the dynamics of GBM. Our review shows that the clustering of fMRI time series has great potential for improving the differentiation between various subtypes of GBM, which is pivotal for developing personalized therapeutic strategies. Moreover, this method proves to be effective in capturing temporal changes occurring in GBM, enhancing the monitoring of disease progression and response to treatment. By thoroughly examining and consolidating the current research, this paper contributes to the understanding of how clustering techniques applied to fMRI data can refine the characterization of GBM. This article emphasizes the importance of incorporating cutting-edge data analysis techniques into neuroimaging and neuro-oncology research. By providing a detailed perspective, this approach may guide future investigations and boost the development of tailored therapeutic strategies for GBM. [ABSTRACT FROM AUTHOR]

Dopaminergic dysfunction in the basal ganglia, particularly in the posterior putamen, is often viewed as the primary pathological mechanism behind motor slowing (i.e. bradykinesia) in Parkinson's disease. However, striatal dopamine loss fails to account for interindividual differences in motor phenotype and rate of decline, implying that the expression of motor symptoms depends on additional mechanisms, some of which may be compensatory in nature. Building on observations of increased motor-related activity in the parieto-premotor cortex of Parkinson patients, we tested the hypothesis that interindividual differences in clinical severity are determined by compensatory cortical mechanisms and not just by basal ganglia dysfunction. Using functional MRI, we measured variability in motor- and selection-related brain activity during a visuomotor task in 353 patients with Parkinson's disease (≤5 years disease duration) and 60 healthy controls. In this task, we manipulated action selection demand by varying the number of possible actions that individuals could choose from. Clinical variability was characterized in two ways. First, patients were categorized into three previously validated, discrete clinical subtypes that are hypothesized to reflect distinct routes of α-synuclein propagation: diffuse-malignant (n = 42), intermediate (n = 128) or mild motor-predominant (n = 150). Second, we used the scores of bradykinesia severity and cognitive performance across the entire sample as continuous measures. Patients showed motor slowing (longer response times) and reduced motor-related activity in the basal ganglia compared with controls. However, basal ganglia activity did not differ between clinical subtypes and was not associated with clinical scores. This indicates a limited role for striatal dysfunction in shaping interindividual differences in clinical severity. Consistent with our hypothesis, we observed enhanced action selection-related activity in the parieto-premotor cortex of patients with a mild-motor predominant subtype, both compared to patients with a diffuse-malignant subtype and controls. Furthermore, increased parieto-premotor activity was related to lower bradykinesia severity and better cognitive performance, which points to a compensatory role. We conclude that parieto-premotor compensation, rather than basal ganglia dysfunction, shapes interindividual variability in symptom severity in Parkinson's disease. Future interventions may focus on maintaining and enhancing compensatory cortical mechanisms, rather than only attempting to normalize basal ganglia dysfunction. [ABSTRACT FROM AUTHOR]