Fusiform Gyrus Research Articles

Altered Blood Oxygen Level-Dependent Signal Stability in the Brain of Patients with Major Depressive Disorder Undergoing Resting-State Functional Magnetic Resonance Imaging

Introduction: Major depressive disorder (MDD) is a common, relapse-prone psychiatric disorder with unknown pathogenesis. Previous studies on resting-state functional magnetic resonance imaging of MDD have mostly focused on the spontaneous activity of blood oxygen level-dependent (BOLD) signals; however, a few studies have investigated BOLD signal stability. Methods: We conducted a resting-state functional study in 42 patients with MDD and 42 healthy controls (HC) matched for age and sex. This included the BOLD signal stability, resting-state functional connectivity (RSFC) analysis, correlation analysis, and support vector machine (SVM) analysis. Results: The BOLD signal stability of the left fusiform gyrus, right inferior temporal gyrus, right temporal pole superior temporal gyrus, and left thalamus was significantly lower in the MDD group compared to the HC group. Further RSFC analysis revealed that the connectivity between right inferior temporal gyrus and both left inferior temporal gyrus and left supramarginal gyrus was significantly reduced in the MDD group. Additionally, the RSFC levels of left thalamus and right thalamus were decreased. Combining BOLD signal stability and RSFC, the SVM-based classification model achieved an accuracy of 80.95% (sensitivity: 78.57%; specificity: 83.33%; receiver-operating characteristic area under the curve: 0.8793). Conclusion: The integration of the BOLD signal stability index and RSFC index demonstrates a robust capability to differentiate between individuals with MDD and HC subjects. We tentatively believe that a combination of the BOLD signal stability index and RSFC can be used to diagnose MDD.

Parieto-Frontal networks mediate contextual influences in the appraisal of pain and disgust facial expressions.

We appraise other people's emotions by combining multiple sources of information, including somatic facial/body reactions and the surrounding context. A wealthy literature revealed how people take into account contextual information in the interpretation of facial expressions, but the mechanisms mediating such influence still need to be duly investigated. Across two experiments, we mapped the neural representations of distinct (but comparably unpleasant) negative states, pain and disgust, as conveyed by naturalistic facial expressions or contextual sentences. Negative expressions led to shared activity in fusiform gyrus and superior temporal sulcus. Instead, pain contexts recruited supramarginal, postcentral and insular cortex, whereas disgust contexts triggered the temporo-parietal cortex and hippocampus/amygdala. When pairing the two sources of information together, we found higher likelihood of classifying an expression according to the sentence preceding it. Furthermore, networks specifically involved in processing contexts were re-enacted whenever a face followed said context. Finally, the perigenual medial prefrontal cortex showed increased activity for consistent (vs inconsistent) face-contexts pairings, suggesting that it integrates state-specific information from the two sources. Overall, our study reveals the heterogeneous nature of face-context information integration, which operates both according to a state-general and state-specific principle, with the latter mediated by the perigenual medial prefrontal cortex.Significance Statement With the aid of controlled database and a comprehensive paradigm, our study provides new insights of the brain and behavioral processes mediating contextual influences on face emotion-specific processing. Our results reveal that context operates both in face-independent and face-conditional fashion, by biasing the interpretation of any face towards the state implied by associated context, and also triggering processes that monitor the consistency between the different sources of information. Overall, our study unveils key neural processes underlying the coding of state-specific information from both face and context and sheds new light on how they are integrated within the medial prefrontal cortex.

Brain MRI Lesions in Alexia Without Agraphia: A Case-Control Study.

Alexia without agraphia (AWA) is an acquired reading disturbance associated with left posterior cerebral artery (PCA) infarction. Based on autopsy and neuroimaging, there are two explanations for its pathogenesis: a visual cortex-language cortex disconnection and a visual word-form agnosia. Our goal was to discover if more refined brain imaging in a case-control study would provide further imaging support for either of these hypotheses. A neuroradiologist masked to the presence of AWA reviewed diffusion-weighted and fluid-attenuated inversion recovery brain MRIs in patients who had left PCA infarctions with AWA (9 patients) or without AWA (18 patients) to characterize lesions in the splenium, left forceps major, and left fusiform gyrus. Patients with AWA had various combinations of lesions in the splenium, left forceps major, and left fusiform gyrus. One of these regions was involved in 3 patients, 2 were involved in 3 patients, and 3 were involved in 3 patients. Most (89%) patients without AWA lacked involvement of any of these 3 regions. Our data provide imaging evidence for the two existing hypotheses of AWA. Involvement of any of these lesions on MRI imaging should encourage clinicians to obtain further neuropsychological testing.

The Influence of Music Reading on Spatial Working Memory and Self-Assessment Accuracy.

Previous research has suggested that Western musicians, who generally demonstrate proficiency in reading musical scores, exhibit superior performance in visuospatial working memory tasks compared to non-musicians. Evidence indicates brain activation in regions such as the left inferior parietal lobe and the right posterior fusiform gyrus during music reading, which are associated with visuospatial processing. This study aimed to explore how musical training influences spatial working memory and to examine the relationship between self-assessment accuracy and cognitive performance. A visuospatial working memory test, the Corsi block-tapping test (CBT), was administered to 70 participants, including 35 musicians with experience in music reading and 35 non-musicians. CBT performances were compared between groups, controlling for sex and age differences using analysis of covariance. Participants were also asked to self-assess their visuospatial capabilities. Musicians performed significantly better than non-musicians in the CBT and demonstrated greater metacognitive accuracy in evaluating their visuospatial memory capacities. A total of 46.34% of musicians who claimed good performance on the CBT did in fact perform well, in comparison with 14.63% of non-musicians. Sex influenced the outcomes of spatial working memory, while age did not significantly affect performance. This self-awareness of visuospatial capabilities reflects a form of metacompetence, encompassing reflective thinking and the ability to assess one's cognitive skills. Furthermore, while differences in spatial working memory between musicians and non-musicians appear to be related to executive functions associated with general music practice, further investigation is needed to explore other potential influences beyond musical experience.

Dissecting the causal role of early inferior frontal activation in reading.

Cognitive models of reading assume that speech production occurs after visual and phonological processing of written words. This traditional view is at odds with more recent magnetoencephalography studies showing that the left posterior inferior frontal cortex (pIFC) classically associated with spoken production responds to print at 100-150 ms after word-onset, almost simultaneously with posterior brain regions for visual and phonological processing. Yet the theoretical significance of this fast neural response remains open to date. We used transcranial magnetic stimulation (TMS) to investigate how the left pIFC contributes to the early stage of reading. In Experiment 1, 23 adult participants (14 females) performed three different tasks about written words (oral reading, semantic judgment and perceptual judgment) while single-pulse TMS was delivered to the left pIFC, fusiform gyrus or supramarginal gyrus at different time points (50 to 200 ms after word-onset). A robust double dissociation was found between tasks and stimulation sites - oral reading, but not other control tasks, was disrupted only when TMS was delivered to pIFC at 100 ms. This task-specific impact of pIFC stimulation was further corroborated in Experiment 2, which revealed another double dissociation between oral reading and picture naming. These results demonstrate that the left pIFC specifically and causally mediates rapid computation of speech motor codes at the earliest stage of reading and suggest that this fast sublexical neural pathway for pronunciation, although seemingly dormant, is fully functioning in literate adults. Our results further suggest that these left-hemisphere systems for reading overall act faster than known previously.Significance Statement Recent neuroimaging data suggest that left posterior inferior frontal cortex, classically associated with spoken production, responds to print simultaneously with left fusiform and supramarginal gyri, each responsible for visual and phonological processing, contrary to traditional serial cascade models of reading. While the region is now known to mediate different aspects of cognitive processing, the functional significance of this fast neural response remains unclear. Using transcranial magnetic stimulation, we show that early inferior frontal activation plays a specific and causal role in speeded oral reading at 100 ms after word-onset. This fast sublexical neural pathway for pronunciation, although seemingly dormant, is fully functioning in literate adults. We also propose that the left-hemisphere reading systems act differently and faster than known previously.

Cognitive reserve against Alzheimer’s pathology is linked to brain activity during memory formation

The cognitive reserve (CR) hypothesis posits that individuals can differ in how their brain function is disrupted by pathology associated with aging and neurodegeneration. Here, we test this hypothesis in the continuum from cognitively normal to at-risk stages for Alzheimer’s Disease (AD) to AD dementia using longitudinal data from 490 participants of the DELCODE multicentric observational study. Brain function is measured using task fMRI of visual memory encoding. Using a multivariate moderation analysis, we identify a CR-related activity pattern underlying successful memory encoding that moderates the detrimental effect of AD pathological load on cognitive performance. CR is mainly represented by a more pronounced expression of the task-active network encompassing deactivation of the default mode network (DMN) and activation of inferior temporal regions including the fusiform gyrus. We devise personalized fMRI-based CR scores that moderate the impact of AD pathology on cognitive performance and are positively associated with years of education. Furthermore, higher CR scores attenuate the effect of AD pathology on cognitive decline over time. Our findings primarily provide evidence for the maintenance of core cognitive circuits including the DMN as the neural basis of CR. Individual brain activity levels of these areas during memory encoding have prognostic value for future cognitive decline.

Peripheral molecular and brain structural profile implicated stress activation and hyperoxidation in methamphetamine use disorder.

Methamphetamine use disorders (MUDs) cause widespread disruptions in metabolomic and immunologic processes, highlighting the need for new therapeutic approaches. The purpose of this study was to find molecular and neuroimaging biomarkers for methamphetamine addiction. In this study, we recruited 231 patients with MUD at varying stages of withdrawal and 40 healthy controls to quantify the blood levels of 52 molecules using enzyme-linked immunosorbent assay. The overall molecular disruption caused by methamphetamine was inversely related to withdrawal time (P = 0.0008), with partial recovery observed after 1 year of follow-up (P = 2.20 × 10-5). Molecules related to stress, immune activation, oxidative products, and cardiac injury were significantly elevated in all MUD groups, while antioxidation enzymes were downregulated. Additionally, the blood level of brain-derived neurotrophic factor was significantly correlated with gray matter volumes in nine brain regions (fusiform gyrus, orbitofrontal cortex, temporal pole, caudate, cerebellum crus, and vermis, adjusted P < 0.05) among patients with MUD. These findings suggest that patients with MUD exhibit elevated levels of immune response, stress, and oxidative stress, which are associated with brain structural abnormalities.

Diverse frontoparietal connectivity supports semantic prediction and integration in sentence comprehension.

Predictive processing in parietal, temporal, frontal, and sensory cortex allows us to anticipate future meanings to maximize the efficiency of language comprehension, with the temporoparietal junction (TPJ) and inferior frontal gyrus (IFG) thought to be situated towards the top of a predictive hierarchy. Although the regions underpinning this fundamental brain function are well-documented, it remains unclear how they interact to achieve efficient comprehension. To this end we recorded functional magnetic resonance imaging (fMRI) in 22 participants (11 males) while they comprehended sentences presented part-by-part, in which we manipulated the constraint provided by sentential contexts on upcoming semantic information. Using this paradigm, we examined the connectivity patterns of bilateral TPJ and IFG during anticipatory phases (i.e., before the onset of targets) and integration phases (i.e., after the onset of targets). When upcoming semantic content was highly predictable in strong-constraint contexts, both left TPJ and bilateral IFG showed stronger visual coupling, while right TPJ showed stronger connectivity with regions within control, default mode, and visual networks, including IFG, parahippocampal gyrus, posterior cingulate, and fusiform gyrus. These connectivity patterns were weaker when predicted semantic content appeared, in line with predictive coding theory. Conversely, for less predictable content, these connectivity patterns were stronger during the integration phase. Overall, these results suggest that both top-down semantic prediction and bottom-up integration during predictive processing are supported by flexible coupling of frontoparietal regions with control, memory, and sensory systems.Significance Statement Recent work has revealed the neural basis of predictive language comprehension. However, it remains unclear how brain regions change their connectivity in a dynamic fashion to support comprehension in highly predictive and less predictive contexts. Here, we show that stronger frontoparietal connectivity with cognitive control, memory, and sensory areas supports top-down prediction generation in strong-constraint contexts; these connectivity patterns are reduced when the anticipated information appears. This pattern is reversed when upcoming sensory input is unpredictable; connectivity is stronger after word inputs have been presented, allowing semantic integration with preceding low-constraint context. Our findings suggest that both top-down semantic prediction and bottom-up semantic integration in language comprehension rely upon diverse functional coupling of higher-order frontoparietal regions with other brain systems.

Behavioral and neural evidence for difficulty recognizing masked emotional faces.

Facial emotion recognition is vital for human social behavior. During the COVID-19 pandemic, face masks were widely adopted for viral mitigation and remain crucial public health tools. However, questions persist about their impact on emotion recognition and neural processing, especially in children, parents, and young adults. We developed the Masked Affective and Social Cognition task, featuring masked and unmasked faces displaying fear, sadness, and anger. We recruited three racial and ethnically diverse samples: 119 college students, 30 children who entered school age at the beginning of the pandemic, and 31 fathers of the aforementioned children. Of the latter two groups, 41 participants (n = 23 fathers, 18 children) did the Masked Affective and Social Cognition task during a neuroimaging scan, while the remaining 20 participants (n = 8 fathers, 12 children) who were not eligible for scanning completed the task during their lab visit. Behaviorally, we found that participants recognized emotions less accurately when viewing masked faces and also found an interaction of emotion by condition, such that accuracy was particularly compromised by sad masked faces. Neurally, masked faces elicited greater activation in the posterior cingulate, insula, and fusiform gyrus. Anterior insula and inferior frontal gyrus activation were driven by sad, masked faces. These results were consistent across age groups. Among fathers, activation to sad masked faces was associated with stress and depression. Overall, our findings did not depend on previous mask exposure or timing of participation during the pandemic. These results have implications for understanding face emotion recognition, empathy, and socioemotional neurodevelopment. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

An eccentricity gradient reversal across high-level visual cortex.

Human visual cortex contains regions selectively involved in perceiving and recognizing ecologically important visual stimuli such as people and places. Located in the ventral temporal lobe, these regions are organized consistently relative to cortical folding, a phenomenon thought to be inherited from how centrally or peripherally these stimuli are viewed with the retina. While this eccentricity theory of visual cortex has been one of the best descriptions of its functional organization, whether or not it accurately describes visual processing in all category-selective regions is not yet clear. Through a combination of behavioral and functional MRI measurements in 27 participants (17 females), we demonstrate that a limb-selective region neighboring well-studied face-selective regions shows tuning for the visual periphery in a cortical region originally thought to be centrally-biased. We demonstrate that the spatial computations performed by the limb-selective region are consistent with visual experience, and in doing so, make the novel observation that there may in fact be two eccentricity gradients, forming an eccentricity reversal across high-level visual cortex. These data expand the current theory of cortical organization to provide a unifying principle that explains the broad functional features of many visual regions, showing that viewing experience interacts with innate wiring principles to drive the location of cortical specialization.Significance Statement What is the organizing principle of high-level visual cortex? Visual stimuli experienced extensively during childhood, like faces or scenes, give rise to specialized regions in visual cortex. These regions emerge in consistent locations across individuals, thought to result from the retinotopic input of earlier visual cortex. The field has quantified this input as a medial-lateral gradient of retinotopic eccentricity in ventrotemporal cortex that has not yet been mapped beyond the fusiform gyrus. By performing receptive field mapping in limb-selective cortex for the first time we uncover a u-shaped eccentricity gradient which reverses near the lateral Fusiform. These findings produce a parsimonious model of cortical organization incorporating previously uncharacterized regions, offering a new organizing principle of high-level vision.

Global changes in the pattern of connectivity in developmental prosopagnosia.

Developmental prosopagnosia is a neurodevelopmental condition characterized by difficulties in recognizing the identity of a person from their face. While current theories of the neural basis of developmental prosopagnosia focus on the face processing network, successful recognition of face identities requires broader integration of neural signals across the whole brain. Here, we asked whether disruptions in global functional and structural connectivity contribute to the face recognition difficulties observed in developmental prosopagnosia. We found that the left temporal pole was less functionally connected to the rest of the brain in developmental prosopagnosia. This was driven by weaker contralateral connections to the middle and inferior temporal gyri, as well as to the medial prefrontal cortex. The pattern of global connectivity in the left temporal pole was also disrupted in developmental prosopagnosia. Critically, these changes in global functional connectivity were only evident when participants viewed faces. Structural connectivity analysis revealed localized reductions in connectivity between the left temporal pole and a number of regions, including the fusiform gyrus, inferior temporal gyrus, and orbitofrontal cortex. Our findings underscore the importance of whole-brain integration in supporting typical face recognition and provide evidence that disruptions in connectivity involving the left temporal pole may underlie the characteristic difficulties of developmental prosopagnosia.

Neural dissociation between computational and perceived measures of curvature

There is substantial evidence to suggest that preference for visual curvature is a reliable phenomenon. Yet, little is known about the ways in which the encoding of curvature in the brain contributes to hedonic evaluation while participants are actively engaged in making choices about objects varying in curvature. To address this question, we reanalyzed fMRI data collected while participants made aesthetic judgments (beautiful vs. not beautiful) and approach-avoidance decisions (enter vs. exit) in relation to measures of (a) computational curvature, (b) perceived curvature, (c) perceived angularity, and (d) aesthetic pleasure in the domain of architecture. Our results show that a region in early visual cortex (BA 17) encompassing largely areas V2-V3 is sensitive to variation in computational curvature across both beauty judgments and approach-avoidance decisions, whereas a region encompassing the fusiform gyrus (BA 37) exhibits sensitivity to perceived curvature only when participants made beauty judgments. These results contribute to our understanding of the neurobiological basis of curvature preference by demonstrating that the sensitivity of the visual cortex to computational curvature is context invariant, whereas the sensitivity of the fusiform gyrus to perceived curvature varies by context.

Altered neurovascular coupling in semantic variant primary progressive aphasia

Background Semantic variant primary progressive aphasia (svPPA) is one of the main clinical phenotypes of frontotemporal lobar degeneration. Changes in both neuronal activity and cerebral perfusion have been observed in svPPA, suggesting a possible breakdown of neurovascular coupling (NVC). Objective To investigate alterations in NVC and their correlations with clinical manifestations in svPPA patients. Methods In this study, a cohort consisting of 19 subjects diagnosed with svPPA and 36 cognitively unimpaired controls (CUCs) have been enrolled for analysis. All participants underwent multimodal magnetic resonance imaging (MRI) scans, resting-state functional MRI and arterial spin labelling, and neuropsychological assessments. The amplitude of low-frequency fluctuations (ALFF) and cerebral blood flow (CBF) were obtained to measure neural activity and perfusion, respectively. The calculation of voxel CBF-ALFF correlation and CBF/ALFF ratio enables the assessment of global NVC and regional NVC, respectively. Correlations between the CBF/ALFF ratios and cognitive scores of the svPPA patients were analyzed. The relationships between the CBF/ALFF ratios and the cognitive performance of the svPPA patients were investigated through correlational analyses. Results Compared with CUCs, svPPA patients had decreased global CBF-ALFF correlation coefficients ( p &lt; 0.001) and lower CBF/ALFF ratios in bilateral inferior temporal gyrus, fusiform gyrus, left temporal pole and middle temporal gyrus ( p &lt; 0.05). In svPPA patients, the CBF/ALFF ratios in the left inferior and middle temporal gyrus correlated positively with naming ability and general cognition, respectively. Conclusions The study indicate that NVC is disrupted in svPPA patients and is relevant to cognitive and language function.

MEG evidence for left temporal and orbitofrontal involvement in breaking down inflected words and putting the pieces back together

A major puzzle in the visual word recognition literature is how the human brain deals with complex words (e.g., presuppose). Prior work has shown that a multi-stage process is involved, starting with the early, form-based decomposition stage where a word is broken down into smaller pieces called morphemes {pre-}+{suppose} and ending with the recombination stages where the pieces are put back together to access the word’s full meaning. However, most neurolinguistic studies have focused on the first stage, and/or on derivational morphology, which inherently carries both syntactic and semantic information, and this research has overwhelmingly investigated Indo-European languages. Here, we investigate visual word recognition of Tagalog complex words, focusing on inflectional prefixes which allows us to zero in on the contribution of syntactic information during the recombination stage, where both syntactic and semantic information are expected to be analyzed. Using MEG, we replicate previous findings implicating the left fusiform gyrus in segmenting complex words into pieces. We also show that the recombination stages, where the morphological pieces are put back together, activate the left posterior temporal lobe and left orbitofrontal cortex. Although our results support a multi-stage comprehension model of complex words and confirm that these distinct stages are associated with distinct spatiotemporal profiles, we also observed some spatiotemporal differences compared to previous studies on derivational morphology. For the first time, we show that inflected words activate the same core processing profile as derived words in the early (decomposition) stage, while later (recombination) stages of morphological processing point to an earlier and faster recombination of inflected words.

Syntax and the brain: language evolution as the missing link(ing theory)?

This paper provides proof of concept that neurolinguistic research on human language syntax would benefit greatly by expanding its scope to include evolutionary considerations, as well as non-propositional functions of language, including naming/nicknaming and verbal aggression. In particular, an evolutionary approach can help circumvent the so-called granularity problem in studying the processing of syntax in the brain, that is, the apparent mismatch between the abstract postulates of syntax (e.g. Tense Phrase (TP), Determiner Phrase (DP), etc.) and the concrete units of neurobiology (neurons, axons, etc.). First, we decompose syntax into its evolutionary primitives, identifying one of the earliest stages as a simple, flat combination of just one verb and one noun. Next, we identify proxies ("living fossils") of such a stage in present-day languages, including compounds and small clauses, lacking at least some layers of structure, e.g. TPs and DPs. These proxies of ancestral language have been subjected to fMRI neuroimaging experiments. We discuss the finding that less hierarchical small clauses, in contrast to full sentences with TPs and DPs, show reduced activation in the left Broca's area (BA) 44 and the right basal ganglia, consistent with the hypothesis that more recent, more elaborate syntax requires more connectivity in the Broca's-basal ganglia network, whose neuronal density has been significantly enhanced in recent evolution, implicating mutations in FOXP2 and other genes. We also discuss the finding that the processing of ancestral verb-noun compounds, which are typically used for (derogatory) naming and nicknaming, shows enhanced activation in the right fusiform gyrus area (BA 37), the area that is implicated in the processing of metaphoricity and imageability, but also in naming and face recognition, opening up an intriguing possibility that the enhanced face recognition in humans was facilitated by the early emergence of a simple syntactic strategy for naming. The considerations in this paper are consistent with the hypothesis of a gradual gene-culture co-evolution of syntax and the brain, targeting cortico-striatal brain networks. It is also of note that a sound grounding in neurobiology of language should in turn inform syntactic theories themselves.

The mediation role of gray matter volume in the relationship between childhood maltreatment and psychological resilience in adolescents with first-episode major depressive disorder

Previous studies have revealed morphologic alterations in patients with major depressive disorder (MDD) with experiences of childhood trauma. However, the underlying neural mechanisms remain largely unknown. This study aims to explore the brain structural changes and their possible mediation role in the relationship between childhood maltreatment and psychological resilience in drug-naïve adolescents with first-episode MDD. A total of 57 adolescents with first-episode MDD and 36 healthy controls (HCs) completed the T1-weighted magnetic resonance imaging scan. The adverse childhood experiences and current psychological resilience were assessed using the Childhood Trauma Questionnaire-Short Form and the Connor Davidson Resilience Scale, respectively. The voxel-based morphometry approach was applied to examine changes in the gray matter volume (GMV). Compared with the HCs, adolescents with MDD had significantly reduced GMV volumes in the left fusiform gyrus, right orbitofrontal gyrus, right superior temporal gyrus, right calcarine cortex, right middle frontal gyrus, left angular gyrus, right precuneus, right posterior cingulate gyrus, and right posterior central gyrus, as well as significantly increased GMV volumes in the left lenticular putamen and right lenticular pallidum. The GMV of the right calcarine cortex was found to be negatively correlated with the severity of emotional abuse and positively correlated with the level of psychological resilience. Moreover, the GMV of the right calcarine cortex might partially mediate the relationship between childhood maltreatment and psychological resilience. The present study provided further evidence for structural impairments in adolescents with MDD. Our findings also confirmed the important role of depression-related GMV changes in childhood growth experiences and psychological resilience characteristics during adolescent brain maturation.

Alterations of regional brain activity and corresponding brain circuits in drug-naïve adolescents with nonsuicidal self-injury

Nonsuicidal self-injury (NSSI) is one of the major public health problems endangering adolescents. However, the neural mechanisms of NSSI is still unclear. The purpose of this study was to explore regional brain activity and corresponding brain circuits in drug-naïve adolescents with NSSI using amplitude of low-frequency fluctuations (ALFF) combined with functional connectivity (FC) analysis. Thirty-two drug-naïve adolescents with NSSI (NSSI group) and 29 healthy controls matched for sex, age, and level of education (HC group) were enrolled in this study. ALFF and seed-based FC analyses were used to examine the alterations in regional brain activity and corresponding brain circuits. The correlation between ALFF or FC values of aberrant brain regions and clinical characteristics were detected by Pearson correlation analysis. The NSSI group showed increased ALFF in the left inferior and middle occipital gyri, lingual gyrus, and fusiform gyrus; additionally, decreased ALFF in the right medial cingulate gyrus, left anterior cingulate gyrus, and left medial superior frontal gyrus compared to those in the HC group. With the left inferior occipital gyrus as seed, the NSSI group showed increased FC between the left inferior occipital gyrus and the bilateral superior parietal gyrus, right inferior parietal angular gyrus, right inferior frontal gyrus of the insular region, and left precuneus relative to that the HC group. With the left anterior cingulate gyrus as seed, the NSSI group showed increased FC between the left anterior cingulate gyrus and right dorsolateral superior frontal gyrus. With the left lingual gyrus as seed, the NSSI group showed increased FC between the left lingual gyrus and right middle frontal gyrus, and decreased FC between the left lingual gyrus and the left superior temporal gyrus, right supplementary motor area, and left rolandic operculum. With the left fusiform gyrus as seed, the NSSI group showed increased FC between the left fusiform gyrus and left middle and inferior temporal gyrus, and decreased FC between the left fusiform gyrus and the bilateral postcentral gyrus, right precentral gyrus, right lingual gyrus, and left inferior parietal angular gyrus. Moreover, the FC value between the left fusiform gyrus and left inferior temporal gyrus was positively correlated with suicidal ideations score. This study highlights alterations in regional brain activity and corresponding brain circuits in brain regions related to visual and emotional regulation functions in drug-naïve adolescents with NSSI. These findings may facilitate better understand the underlying neural mechanisms of NSSI in adolescents.

Disrupted gray matter connectome in vestibular migraine: a combined machine learning and individual-level morphological brain network analysis

BackgroundAlthough gray matter (GM) volume alterations have been extensively documented in previous voxel-based morphometry studies on vestibular migraine (VM), little is known about the impact of this disease on the topological organization of GM morphological networks. This study investigated the altered network patterns of the GM connectome in patients with VM.MethodsIn this study, 55 patients with VM and 57 healthy controls (HCs) underwent structural T1-weighted MRI. GM morphological networks were constructed by estimating interregional similarity in the distributions of regional GM volume based on the Kullback–Leibler divergence measure. Graph-theoretical metrics and interregional morphological connectivity were computed and compared between the two groups. Partial correlation analyses were performed between significant GM connectome features and clinical parameters. Logistic regression (LR), support vector machine (SVM), and random forest (RF) classifiers were used to examine the performance of significant GM connectome features in distinguishing patients with VM from HCs.ResultsCompared with HCs, patients with VM exhibited increased clustering coefficient and local efficiency, as well as reduced nodal degree and nodal efficiency in the left superior temporal gyrus (STG). Furthermore, we identified one connected component with decreased morphological connectivity strength, and the involved regions were mainly located in the STG, temporal pole, prefrontal cortex, supplementary motor area, cingulum, fusiform gyrus, and cerebellum. In the VM group, several connections in the identified connected component were correlated with clinical measures (i.e., symptoms and emotional scales); however, these correlations did not survive multiple comparison corrections. A combination of significant graph- and connectivity-based features allowed single-subject classification of VM versus HC with significant accuracy of 77.68%, 77.68%, and 72.32% for the LR, SVM, and RF models, respectively.ConclusionPatients with VM had aberrant GM connectomes in terms of topological properties and network connections, reflecting potential dizziness, pain, and emotional dysfunctions. The identified features could serve as individualized neuroimaging markers of VM.

Mapping the basal temporal language network: a SEEG functional connectivity study

The Basal Temporal Language Area (BTLA) is recognized in epilepsy surgery setting when cortical electrical stimulation (CES) of the ventral temporal cortex (VTC) trigger anomia or paraphasia during naming tasks. Despite acknowledging a ventral language stream, current cognitive language models fail to properly integrate this entity. In this SEEG study we used cortico-cortical evoked potentials in nine epileptic patients to assess and compare the effective connectivity of 73 sites in the left VTC of which 26 were deemed eloquent for naming after CES (BTLA). Eloquent sites connectivity supports the existence of a basal temporal language network (BTLN) structured around posterior projectors while the fusiform gyrus behaved as an integrator. BTLN was strongly connected to the amygdala and hippocampus unlike the non-eloquent sites, except for the anterior fusiform gyrus (FG). These observations support the FG as a multimodal functional hub and add to our understanding of ventral temporal language processing.

Language proficiency is associated with neural representational dimensionality of semantic concepts

Previous studies suggest that semantic concepts are characterized by high-dimensional neural representations and that language proficiency affects semantic processing. However, it is not clear whether language proficiency modulates the dimensional representations of semantic concepts at the neural level. To address this question, the present study adopted principal component analysis (PCA) and representational similarity analysis (RSA) to examine the differences in representational dimensionalities (RDs) and in semantic representations between words in highly proficient (Chinese) and less proficient (English) language. PCA results revealed that language proficiency increased the dimensions of lexical representations in the left inferior frontal gyrus, temporal pole, inferior temporal gyrus, supramarginal gyrus, angular gyrus, and fusiform gyrus. RSA results further showed that these regions represented semantic information and that higher semantic representations were observed in highly proficient language relative to less proficient language. These results suggest that language proficiency is associated with the neural representational dimensionality of semantic concepts.