Brain Research最新文献

{"title":"On the limits of LLM surprisal as a functional explanation of the N400 and P600","authors":"Benedict Krieger ,&nbsp;Harm Brouwer ,&nbsp;Christoph Aurnhammer ,&nbsp;Matthew W. Crocker","doi":"10.1016/j.brainres.2025.149841","DOIUrl":"10.1016/j.brainres.2025.149841","url":null,"abstract":"<div><div>Expectations about upcoming words play a central role in language comprehension, with expected words being processed more easily than less expected ones. Surprisal theory formalizes this relationship by positing that cognitive effort is proportional to a word’s negative log-probability in context, as determined by distributional, linguistic, and world knowledge constraints. The emergence of large language models (LLMs) demonstrating the capacity to compute richly contextualized surprisal estimates, has motivated their consideration as models of comprehension. We assess here the relationship of LLM surprisal with two key neural correlates of comprehension – the N400 and the P600 – which differ in sensitivity to semantic association and contextual expectancy. While prior work has focused on the N400, we propose that the P600 may offer a better index of surprisal, as it is unaffected by association while still patterning continuously with expectancy. Using regression-based ERPs (rERPs), we examine data from three German factorial studies to evaluate the extent to which LLM surprisal can account for ERP differences. Our results show that LLM surprisal captures neither component consistently. We find that it is contaminated by simple association, particularly in smaller LLMs. As a result, LLM surprisal can partially account for association-driven N400 effects, but not for the full attenuation of N400 effects. Correspondingly, this property of LLMs compromises their ability to model the P600, which is sensitive to expectancy but not to association.</div></div>","PeriodicalId":9083,"journal":{"name":"Brain Research","volume":"1865 ","pages":"Article 149841"},"PeriodicalIF":2.6,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144811781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Altered white matter integrity and structural network topology in rhegmatogenous retinal detachment: A diffusion tensor imaging study","authors":"Yu Ji ,&nbsp;Qin-Yi Huang ,&nbsp;Xiao-Rong Wu","doi":"10.1016/j.brainres.2025.149876","DOIUrl":"10.1016/j.brainres.2025.149876","url":null,"abstract":"<div><h3>Background</h3><div>Rhegmatogenous retinal detachment (RRD) has been associated with gray matter alterations, but its effects on white matter microstructure and brain network organization remain largely unexplored.</div></div><div><h3>Methods</h3><div>This study included 40 RRD patients and 36 healthy controls (HCs), who underwent diffusion tensor imaging (DTI). Tract-Based Spatial Statistics (TBSS) was used to assess white matter microstructure, and graph theory was applied to quantify structural network topology. In addition, a support vector machine (SVM) classifier was trained to evaluate the discriminative potential of imaging-derived features.</div></div><div><h3>Results</h3><div>Compared to HCs, RRD patients exhibited disrupted white matter network topology, characterized by reduced small-world properties and increased global efficiency. Regionally, widespread alterations in nodal centrality and efficiency were observed, primarily in the frontal, temporal, and occipital lobes. Structural connectivity analysis revealed enhanced integration between attention-related networks and diminished within-network coherence in the default mode and dorsal attention systems. TBSS further identified microstructural abnormalities in the corpus callosum and corona radiata. Notably, degree centrality (DC) achieved the highest classification accuracy in SVM, with an area under the curve (AUC) of 0.9125.</div></div><div><h3>Conclusion</h3><div>RRD patients exhibit widespread alterations in white matter microstructure and structural network topology, indicating central nervous system involvement following acute peripheral visual loss. Among network metrics, DC showed the highest discriminative power. These findings offer preliminary insights into the neural mechanisms of RRD and may inform future studies on disease stratification or prognosis.</div></div>","PeriodicalId":9083,"journal":{"name":"Brain Research","volume":"1865 ","pages":"Article 149876"},"PeriodicalIF":2.6,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144811779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Context controls the ability of unconditional stimulus deflation to mitigate fear relapse","authors":"Payton K. Robinson,&nbsp;Sydney Trask","doi":"10.1016/j.brainres.2025.149877","DOIUrl":"10.1016/j.brainres.2025.149877","url":null,"abstract":"<div><div>Our lab, and others, have recently demonstrated that fear behavior can be weakened following fear acquisition with a footshock unconditional stimulus by presenting a weaker version of that footshock, a phenomenon termed ‘unconditional stimulus deflation’ or US deflation. Unlike extinction, US deflation putatively functions by modifying the original fear memory, potentially making it a more effective candidate for reducing fear and preventing relapse effects often observed following extinction. Here, we adapted our contextual fear US deflation procedure to a delay conditioning paradigm in order to examine common relapse phenomena: renewal and reinstatement. We found that while ABA renewal and reinstatement were unaffected by US deflation, AAB renewal was reduced by US deflation. Our results support similar work in suggesting that prevention of relapse is at least partially dependent on deflation occurring in the same context as training when using a delay fear conditioning procedure.</div></div>","PeriodicalId":9083,"journal":{"name":"Brain Research","volume":"1865 ","pages":"Article 149877"},"PeriodicalIF":2.6,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144811780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sex differences in resilience at puberty depend upon divergent effects of a stress steroid at α4βδ GABAA receptors","authors":"Lindsay A. Kenney ,&nbsp;Michael Tekin ,&nbsp;Daniel DeLeon ,&nbsp;Sofia Marshall ,&nbsp;Sheryl S. Smith","doi":"10.1016/j.brainres.2025.149874","DOIUrl":"10.1016/j.brainres.2025.149874","url":null,"abstract":"<div><div>Resilience is a critical skill that lessens the adverse effects of stress which are increasingly reported in adolescents, where sex differences are noted. It is not known how this process develops in adolescence when unique changes in neuronal properties occur. For this study, pubertal mice were tested for their coping ability following 2-week restraint. We show here that this predictable stress produced resilience in pubertal female mice where time immobile in the forced swim test (FST) decreased by ∼50 % (P &lt; 0.0001), an effect that extended into adulthood, and increased escape behavior 8-fold (P = 0.01). This effect was not seen in pubertal male or adult female mice. This process required the stress steroid 3α-OH,5α-pregnan-20-one (THP, allopregnanolone) and its primary target, α4βδ GABA_A receptors (GABARs). These receptors emerge at puberty in prelimbic prefrontal cortex (PL PFC) and basolateral amygdala (BLA), which play a pivotal role in resilient behavior. Stress-induced release of THP decreased anxiety-like behavior (increasing open arm time in the elevated plus maze) and enhanced PFC-dependent learning (temporal order recognition) after 1d restraint in pubertal female, but not male, mice while differentially altering α4βδ expression in PL and BLA. This divergent THP-induced effect ultimately increased and decreased mushroom spine density in PL and BLA, respectively, to produce a circuit optimized for resilient behavior in the pubertal females. These findings demonstrate a novel mechanism for the development of resilience unique to the pubertal period. The results from the present study may suggest therapeutic strategies for adolescent stress which would impact mental health in adulthood.</div></div>","PeriodicalId":9083,"journal":{"name":"Brain Research","volume":"1865 ","pages":"Article 149874"},"PeriodicalIF":2.6,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144811715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Therapeutic effects of low-intensity transcranial ultrasound on neurological recovery in rat models of MCAO with varying injury severities","authors":"Yuyao Lai ,&nbsp;Peishan Wu ,&nbsp;Xinhan Cao ,&nbsp;Mingjun He ,&nbsp;Hongmei Wen ,&nbsp;Li Luo ,&nbsp;Xiaojing Long ,&nbsp;Lijie Ren ,&nbsp;Yao Wang","doi":"10.1016/j.brainres.2025.149871","DOIUrl":"10.1016/j.brainres.2025.149871","url":null,"abstract":"<div><h3>Background</h3><div>Low-intensity transcranial ultrasound (LITUS) is a safe, non-invasive neuromodulation method shown to improve neurological function after ischemic stroke in middle cerebral artery occlusion (MCAO) rats models. Given that the degree of severity of ischemic damage may influence treatment outcomes, it is important to investigate the therapeutic performance of LITUS in various injury models to provide a comprehensive understanding to support its clinical application.</div></div><div><h3>Methods</h3><div>Sixty adult male SD rats were randomly divided into four groups: Sham (S), MCAO only (M), MCAO + high-intensity transcranial ultrasound (HITUS) injury + LITUS treatment (MHL), and MCAO + LITUS treatment (ML), with 15 rats per group. MCAO models were verified by 9.4 T MRI. LITUS was administered to MHL and ML groups for 20 min daily over 14 days. Behavioral tests, blood biomarkers, and molecular analyses (Western blot, qPCR, immunofluorescence) were used to evaluate neurological function, inflammation, and neurovascular changes.</div></div><div><h3>Results</h3><div>LITUS significantly improved neurological, motor, and cognitive functions in MCAO rats with varying injury severities. Treated animals showed better body weight recovery, lower Longa scores, improved motor coordination, and enhanced exploratory and recognition behavior. Mechanistically, LITUS reduced peripheral inflammation, downregulated iNOS expression, and regulated glucose, lipid, and homocysteine levels, supporting systemic homeostasis. It also promoted hematopoiesis and upregulated angiogenic markers (VEGF-A, eNOS, CD31), enhancing vascular regeneration in the ischemic cortex. Furthermore, LITUS activated the BDNF/nNOS signaling pathway, facilitating neurogenesis and neuronal repair. These findings suggest that LITUS exerts multi-target protective effects through coordinated regulation of inflammation, metabolism, angiogenesis, and neuroregeneration, offering strong therapeutic potential for stroke recovery.</div></div><div><h3>Conclusion</h3><div>LITUS treatment can improve neurological and motor dysfunction in MCAO rats with varying degrees of injury. The potential underlying mechanism of LITUS is through the regulation of the level of inflammation and promoting angiogenesis and neurogenesis.</div></div>","PeriodicalId":9083,"journal":{"name":"Brain Research","volume":"1865 ","pages":"Article 149871"},"PeriodicalIF":2.6,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144803509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ERP prediction error responses under temporal constraints","authors":"Álvaro Darriba ,&nbsp;Hamdi Habacha ,&nbsp;Yang Seok Cho ,&nbsp;Florian Waszak","doi":"10.1016/j.brainres.2025.149867","DOIUrl":"10.1016/j.brainres.2025.149867","url":null,"abstract":"<div><div>Anticipating future events is fundamental to adaptive behaviour. This study used EEG to examine how the brain processes multiple concurrent predictions under time constraints. On each trial, participants heard two auditory cues predicting different features (tilt and spatial frequency) of an upcoming visual stimulus (a Gabor patch), with cues presented either 200 ms or 1000 ms apart. The visual stimulus could either match both predicted features, violate both, or match only one while violating the other. We analysed event-related potentials (ERPs) to the Gabor patch to assess prediction error (PE) responses. Violations of the first cue’s prediction consistently elicited robust N2b responses, even when the second cue’s prediction was accurate. Violations of both cues produced similarly strong N2b amplitudes, while isolated violations of the second cue had no significant effect. No differences emerged between short and long cue intervals, suggesting that the temporal gap did not modulate PE processing. These results point to a bottleneck in integrating sequential predictions, with earlier cues dominating PE-related EEG responses under temporal constraints.</div></div>","PeriodicalId":9083,"journal":{"name":"Brain Research","volume":"1865 ","pages":"Article 149867"},"PeriodicalIF":2.6,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144772801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Angiotensin in the nervous system","authors":"Claudia Bregonzio","doi":"10.1016/j.brainres.2025.149865","DOIUrl":"10.1016/j.brainres.2025.149865","url":null,"abstract":"","PeriodicalId":9083,"journal":{"name":"Brain Research","volume":"1864 ","pages":"Article 149865"},"PeriodicalIF":2.6,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144764542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cannabinoids drive feeding through AgRP neurons","authors":"Yavuz Yavuz ,&nbsp;Habibe Goren ,&nbsp;Bayram Yilmaz","doi":"10.1016/j.brainres.2025.149857","DOIUrl":"10.1016/j.brainres.2025.149857","url":null,"abstract":"<div><div>The endocannabinoid system regulates energy balance and feeding behavior, primarily through cannabinoid type-1 receptors (CB1Rs). While CB1R activation is known to increase food intake, the role of agouti-related peptide (AgRP) neurons of the arcuate nucleus (ARC) in this process remains unclear. Using slice electrophysilogy we found that the CB1R agonist ACEA reduced inhibitory postsynaptic currents (sIPSCs) in AgRP neurons. Ablating AgRP neurons diminished the hyperphagic and anxiolytic effects of CB1R agonist ACEA, suggesting that intact AgRP neuron circuits are necessary. Conversely, CB1R antagonism in AgRP-ablated mice increased food intake, suggesting compensatory mechanisms. These results suggest that cannabinoid action on the synapses on AgRP neurons may contribute its feeding regulatory actions.</div></div>","PeriodicalId":9083,"journal":{"name":"Brain Research","volume":"1865 ","pages":"Article 149857"},"PeriodicalIF":2.6,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144752338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel contrastive Dual-Branch Network (CDB-Net) for robust EEG-Based Alzheimer’s disease diagnosis","authors":"Zakaria Alouani ,&nbsp;Oussama El Gannour ,&nbsp;Shawki Saleh ,&nbsp;Abdeljalil El-Ibrahimi ,&nbsp;Othmane Daanouni ,&nbsp;Bouchaib Cherradi ,&nbsp;Omar Bouattane","doi":"10.1016/j.brainres.2025.149863","DOIUrl":"10.1016/j.brainres.2025.149863","url":null,"abstract":"<div><div>Alzheimer’s Disease (AD) is neurodegenerative disorder that causes cognitive decline, memory loss, confusion, and changes in behavior. Early and accurate detection is important for timely intervention, current diagnostic methods can be slow, expensive, and have limited sensitivity. Electroencephalography (EEG) offers a simple and non-invasive way to measure brain activity, and it has shown promise in supporting AD diagnosis. However, EEG signals are often affected by noise—such as muscle movement, blinking, or electrical interference—which can make it harder for models to give reliable results. To address these challenges, we introduce CDB-Net (Contrastive Dual-Branch Network), a deep learning model built to improve the accuracy and robustness of EEG-based AD classification. The model uses two parallel branches: one processes clean EEG data, while the other processes a noisy version of the same data. By training these branches together using contrastive learning, the model learns to focus on features that stay consistent even when the signal is distorted by noise. A classification head is trained jointly using cross-entropy loss for downstream diagnosis. We tested our method on a public EEG dataset and found that CDB-Net achieved 97.92% accuracy on clean data and 83.41% accuracy even under adversarial attacks (FGSM), outperforming traditional machine learning classifiers and deep learning baselines models. These results highlight the effectiveness of contrastive dual-branch learning in enhancing model generalization and robustness, positioning CDB-Net as a promising tool for reliable EEG-based clinical decision support in the context of Alzheimer’s Disease diagnosis.</div></div>","PeriodicalId":9083,"journal":{"name":"Brain Research","volume":"1865 ","pages":"Article 149863"},"PeriodicalIF":2.6,"publicationDate":"2025-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144723958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sex differences in serotonergic control of daytime activities in diurnal Nile grass rats","authors":"Sakura Tamogami ,&nbsp;Miho Okeya ,&nbsp;Ryoei Suzuki ,&nbsp;Hiromu Amano ,&nbsp;Riona Yamamoto ,&nbsp;Takatoshi Mochizuki ,&nbsp;Yoan Cherasse ,&nbsp;Takeshi Sakurai ,&nbsp;Tomoko Yoshikawa ,&nbsp;Eri Morioka ,&nbsp;Masayuki Ikeda","doi":"10.1016/j.brainres.2025.149862","DOIUrl":"10.1016/j.brainres.2025.149862","url":null,"abstract":"<div><div>The mechanisms underlying day-active behaviors in diurnal species are still unclear. We lesioned midbrain serotonergic neurons and monitored the effect on spontaneous locomotor activity in diurnal Nile grass rats. First, serotonergic neuron localization was visualized by tryptophan hydroxylase 2 immunofluorescence staining. Using this position on the brain map of Nile grass rat, dorsal raphe nucleus (DRN) lesions were produced by microinjection of an adeno-associated virus (AAV) carrying diphtheria toxin-fragment A (DTA) or the serotonergic neuron toxin 5,7-dihydroxytryptamine (5,7-DHT). Spontaneous locomotor rhythms were monitored for 1 week following a recovery period. The 5,7-DHT lesions destroyed approximately 90 % of tryptophan hydroxylase 2-positive neurons in the DRN and chronically increased daytime activity in female Nile grass rats. The results are independent of estrous cycles because estrous cycles were paused in this species under male-isolated recording environments. AAV-DTA lesions, which were driven by nonspecific CMV-Cre, partially (&lt;60 %) destroyed DRN serotonergic neurons but failed to modulate activity levels. Additionally, neither 5,7-DHT nor AAV-DTA modulated night-time activities. Interestingly, 5,7-DHT produced the same damage in DRN serotonergic neurons in male Nile grass rats but had little effect on their activity. Furthermore, the depression index, determined by a tail suspension test, was not modulated by DRN lesions regardless of the lesion method or sex of Nile grass rats. Previous studies showed that diurnal activity in Nile grass rats is highly dependent on light intensity. Thus, disinhibition of photic inputs by DRN lesions may be a plausible mechanism, although the underlying mechanisms require further investigation.</div></div>","PeriodicalId":9083,"journal":{"name":"Brain Research","volume":"1865 ","pages":"Article 149862"},"PeriodicalIF":2.6,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144723959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}