Brain Sciences最新文献

Background: Repetitive peripheral magnetic stimulation (rPMS) delivers magnetic pulses to peripheral nerves and muscles, producing afferent input that can modulate corticospinal excitability (CSE). While the effects of rPMS on upper-limb muscles have been explored, its short-term effects on lower-limb CSE remain less understood. This study aimed to investigate the short-term effects of rPMS on CSE in the tibialis anterior (TA) muscle among healthy individuals. Methods: Twenty participants completed a repeated- measure, pre-post study. rPMS was applied to the non-dominant TA muscle at 10% above motor threshold for 15 min. CSE was assessed using transcranial magnetic stimulation (TMS), with measurements of motor evoked potential (MEP) amplitude, latency, and duration recorded at baseline, immediately after, 30 min, and 60 min post-stimulation. All analyses were conducted on clean datasets following removal of artifact-related outliers. Results: MEP amplitude showed a significant main effect of Side (p = 0.005), with greater values on the stimulated compared to the non-stimulated side. No significant main effects were found for Time (p = 0.351) or for the Side × Time interaction (p = 0.900). Descriptively, the largest increase in amplitude on the stimulated side was observed at 30 min post-stimulation (12% above baseline). MEP latency and duration showed no significant main or interaction effects. Conclusions: In conclusion, a single rPMS session applied to the TA produced a modest, side-specific increase in CSE lasting up to 60 min, as reflected in MEP amplitude. However, the absence of a significant time effect and perhaps non-optimized stimulation parameters limit the interpretation of sustained neuromodulatory effects. Future studies should examine optimal stimulation parameters and explore underlying mechanisms using measures such as the cortical silent period and interhemispheric inhibition.

Background: The role of cognitive load theory (CLT) in understanding effective pedagogy has received increased attention in the fields of education and psychology in recent years. A considerable amount of literature has been published on the CLT construct as foundational guidance for instructional design by focusing on managing cognitive load in working memory to enhance learning outcomes. However, recent neuroscientific findings and practical critiques suggest that CLT's emphasis on content-focused instruction and cognitive efficiency may overlook the complexity of human learning.

Methods: This conceptual paper synthesises evidence from cognitive science, developmental psychology, neuroscience, health sciences and educational research to examine the scope conditions and limitations of CLT when applied as a general framework for K-12 learning. One of the major theoretical issues identified is the lack of consideration for the broad set of interpersonal and self-management skills, creating potential limitations for real-world educational contexts, where social-emotional and self-regulatory abilities are as crucial as cognitive competencies.

Results: As a result of the critique, this paper introduces the Neurodevelopmental Informed Holistic Learning and Development Framework as a neuroscience-informed construct that integrates cognitive, emotional, and interpersonal dimensions essential for effective learning.

Conclusions: In recognising the limitations of CLT, the paper offers practitioners contemporary, neurodevelopmentally informed insights that extend beyond cognitive efficiency alone and better reflect the multidimensional nature of real-world learning.

Dementia is a rapidly growing global health challenge, underscoring the urgent need for effective strategies aimed at the prevention and early detection of cognitive decline [...].

Background/Objectives: Narrative differences in autism spectrum disorder (ASD) and subtle and parallel differences among their first-degree relatives suggest potential genetic liability to this critical social-communication skill. Effective social-communication relies on coordinating signals across modalities, which is often disrupted in ASD. Therefore, the current study examined the coordination of fundamental skills-gaze and speech-as a potential mechanism underlying narrative and broader pragmatic differences in ASD and their first-degree relatives. Methods: Participants included 35 autistic individuals, 41 non-autistic individuals, 90 parents of autistic individuals, and 34 parents of non-autistic individuals. Participants narrated a wordless picture book presented on an eye-tracker, with gaze and speech simultaneously recorded and subsequently coded. Time series analyses quantified their temporal coordination (i.e., the temporal lead of gaze to speech) and content coordination (i.e., the amount of gaze-speech content correspondence). These metrics were then compared between autistic and non-autistic groups and between parent groups and examined in relation to narrative quality and conversational pragmatic language skills. Results: Autistic individuals showed reduced temporal coordination but increased content coordination relative to non-autistic individuals with no significant differences found between parent groups. In both autistic individuals, and parent groups combined, increased content coordination and reduced temporal coordination were linked to reduced narrative quality and pragmatic language skills, respectively. Conclusions: Reduced temporal and increased content coordination may reflect a localized strategy of labeling items upon visualization. This pattern may indicate more limited visual, linguistic, and cognitive processing and underlie differences in higher-level social-communicative abilities in ASD. To our knowledge, this study is the first to identify multimodal skill coordination as a potential mechanism contributing to higher-level social-communicative differences in ASD and first-degree relatives, implicating mechanism-based interventions to support pragmatic language skills in ASD.

Background: Emotions substantially influence human eating behavior, but while negative affect has been consistently associated with maladaptive eating patterns, the role of positive affect remains underexplored. Thereby, emotion regulation (ER) is considered a key mechanism through which affective states may influence eating behavior. However, its mediating role remains unclear, particularly among non-clinical populations. Objectives: This study aimed to investigate the potential mediating role of ER in the relationship between negative and positive affect and maladaptive eating behavior in a non-clinical adult sample. Methods: This cross-sectional online survey was administered to a general-population convenience sample of 189 adults. Participants completed four standardized self-report questionnaires: Eating Attitudes Test (EAT-26), Positive and Negative Affect Schedule (PANAS), Difficulties in Emotion Regulation Scale (DERS-36), and Depression Anxiety Stress Scale (DASS-21). Correlational analyses and multiple regression models were used to examine the relationships between variables and to test the mediating role of ER. Results: Negative affect was significantly associated with both maladaptive eating behavior (r = 0.29, p < 0.01) and ER difficulties (r = 0.51, p < 0.01). Positive affect was only negatively related to emotion dysregulation (r = -0.47, p < 0.01). ER did not mediate the relationship between either positive or negative affect and maladaptive eating behavior. Conclusions: Findings underscore the influence of negative affect in maladaptive eating behavior, independently of ER. Although positive affect did not directly predict disordered eating behavior, its association with reduced ER difficulties warrants further exploration of its potential protective role.

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in childhood, characterized by persistent inattention, hyperactivity, and impulsivity. This narrative review aims to synthesize and critically evaluate recent large-scale magnetic resonance imaging (MRI) studies to clarify the neuroanatomical and functional brain alterations associated with ADHD in children. By addressing current gaps in understanding, this work seeks to identify reliable neurobiological markers that could improve diagnostic accuracy and guide personalized interventions. The literature reveals that large-scale structural MRI studies consistently report abnormal development in total cortical volume and surface area, prefrontal cortex volume, and basal ganglia volume in children with ADHD. Moreover, gray matter alterations show significant age-dependent effects, with the degree of impairment potentially serving as neurobiological markers. Diffusion magnetic resonance imaging studies reveal disrupted white matter microstructures in regions such as the left uncinate fasciculus, superior and inferior longitudinal fasciculi, corpus callosum, cingulum, and internal capsule. Importantly, these white matter abnormalities often persist into adulthood, highlighting their clinical relevance. Functional MRI findings indicate reduced global connectivity within core hubs of the default mode network in children with ADHD. Furthermore, deficits in inhibitory control identified via fMRI may represent one of the neurofunctional signatures that differentiates ADHD from typically developing controls. By consolidating evidence from large-scale multimodal MRI studies, this review provides a comprehensive understanding of the neurodevelopmental alterations in ADHD and underscores their potential utility for improving diagnosis and treatment.

Background/objectives: Intracranial arachnoid cysts (Acs) are congenital, usually benign lesions that are frequently regarded as clinically silent in adulthood. Nonetheless, growing evidence indicates that Acs may be associated with subtle but measurable cognitive dysfunction. This systematic review synthesizes neuropsychological and functional neuroimaging findings in adults with intracranial Acs, with a focus on cognitive profiles, functional interactions with the adjacent cortex, and postoperative reversibility.

Methods: In accordance with PRISMA 2020 guidelines, MEDLINE/PubMed and Scopus were searched for English-language studies published up to 2023 that reported neuropsychological assessments and/or functional neuroimaging in adult patients with Acs, including single-case reports, case series, and group studies with pre- and post-operative data.

Results: Sixty studies met the inclusion criteria. Across anatomical locations, Acs were most consistently associated with impairments in verbal and visual memory and learning, attention, and executive functions, as well as reduced processing or psychomotor speed, whereas language deficits were less consistently observed. Several studies reported postoperative improvement in one or more cognitive domains, suggesting partial reversibility in selected patients. Functional neuroimaging findings revealed altered cortical function in regions adjacent to the cyst, including reduced regional metabolism or cerebral blood flow and task-related activation changes, supporting a functional interaction between Acs and the neighboring cortex.

Conclusions: Overall, adults with Acs may exhibit subtle cognitive alterations that vary according to cyst location and appear to be moderated by compensatory mechanisms. These findings underscore the clinical relevance of systematic neuropsychological evaluation and highlight the need for prospective, standardized studies integrating cognitive and neuroimaging outcomes.

Background: Repetitive peripheral magnetic stimulation (rPMS) has emerged as a promising non-invasive treatment modality for reducing muscle hypertonus and spasticity. However, standardized protocols regarding stimulation parameters, particularly the number of stimuli required to achieve therapeutic effects, remain largely undefined. Methods: In an exploratory study, seventeen healthy participants (15 male, 2 female) underwent progressive rPMS treatments at 5 Hz frequency with incrementally increasing stimulus counts (105, 210, 315, 420, and 840 stimuli). Seventeen participants served as controls (11 male, 6 female) receiving sham stimulation. Achilles tendon reflexes were elicited using a computer-controlled reflex hammer, and compound muscle action potential (CMAP) peak-to-peak amplitudes were recorded via surface electromyography before and immediately after each stimulation session. Results: The overall repeated-measures ANOVA indicated a significant main effect (F(5, 80) = 4.98, p = 0.001, η²_p = 0.237). All rPMS treatments produced significant reductions in CMAP amplitudes compared to baseline (p < 0.05). No progressive dose-dependent relationship was observed between stimulus count and response magnitude, suggesting a threshold effect rather than progressive inhibition. Control group showed no significant changes (p ≤ 0.56). Conclusions: Low-frequency (5 Hz) rPMS produces rapid inhibitory effects on spinal reflex circuits with onset after as few as 105 stimuli. These findings indicate that treatment effects can be achieved with substantially fewer stimuli than previously assumed. Further research is needed to identify parameters capable of achieving greater reflex suppression.

Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique that utilizes magnetic fields to induce cortical electric currents, enabling both the measurement and modulation of neuronal activity. Initially developed as a diagnostic tool, TMS now serves dual roles in clinical neurology, offering insight into neurophysiological dysfunctions and the therapeutic modulation of abnormal cortical excitability. This review examines key TMS outcome measures, including motor thresholds (MT), input-output (I/O) curves, cortical silent periods (CSP), and paired-pulse paradigms such as short-interval intracortical inhibition (SICI), short-interval intracortical facilitation (SICF), intracortical facilitation (ICF), long interval cortical inhibition (LICI), interhemispheric inhibition (IHI), and short-latency afferent inhibition (SAI). These biomarkers reflect underlying neurotransmitter systems and can aid in differentiating neurological conditions. Diagnostic applications of TMS are explored in Parkinson's disease (PD), dystonia, essential tremor (ET), Alzheimer's disease (AD), and mild cognitive impairment (MCI). Each condition displays characteristic neurophysiological profiles, highlighting the potential for TMS-derived biomarkers in early or differential diagnosis. Therapeutically, repetitive TMS (rTMS) has shown promise in modulating cortical circuits and improving motor and cognitive symptoms. High- and low-frequency stimulation protocols have demonstrated efficacy in PD, dystonia, ET, AD, and MCI, targeting the specific cortical regions implicated in each disorder. Moreover, the successful application of TMS in differentiating and treating AD and MCI underscores its clinical utility and translational potential across all neurodegenerative conditions. As research advances, increased attention and investment in TMS could facilitate similar diagnostic and therapeutic breakthroughs for other neurological disorders that currently lack robust tools for early detection and effective intervention. Moreover, this review also aims to underscore the importance of maintaining standardized TMS protocols. By highlighting inconsistencies and variability in outcomes across studies, we emphasize that careful methodological design is critical for ensuring the reproducibility, comparability, and reliable interpretation of TMS findings. In summary, this review emphasizes the value of TMS as a distinctive, non-invasive approach to probing brain function and highlights its considerable promise as both a diagnostic and therapeutic modality in neurology-roles that are often considered separately.

Background: Cholinesterase inhibitors (ChEIs) are commonly prescribed for the treatment of Alzheimer's disease (AD) and achieve long-term benefits for cognition and survival in real-world settings. However, the discontinuation rate is high due to their side effects, with gastrointestinal (GI) symptoms hampering long-term prescriptions. The risk of side effects associated with rivastigmine was previously shown to be lower with transdermal delivery than with oral capsules; however, this has yet to be examined in detail for donepezil, the most widely used ChEI. The daily application of a donepezil transdermal patch was officially approved in Japan in 2023. The incidence of side effects was lower with the donepezil transdermal patch than with oral donepezil in healthy volunteers, but has not yet been assessed in clinical settings. Results: We herein report three AD patients in two different memory clinics who developed GI symptoms with oral ChEIs that were attenuated by switching to the donepezil transdermal patch. Conclusions: The donepezil transdermal patch may improve tolerability and adherence in patients who develop gastrointestinal adverse effects with oral donepezil.