Basal temporal language area revisited in Japanese language with a language function density map.

We revisited the anatomo-functional characteristics of the basal temporal language area (BTLA), first described by Lüders et al. (1986), using electrical cortical stimulation (ECS) in the context of Japanese language and semantic networks. We recruited 11 patients with focal epilepsy who underwent chronic subdural electrode implantation and ECS mapping with multiple language tasks for presurgical evaluation. A semiquantitative language function density map delineated the anatomo-functional characteristics of the BTLA (66 electrodes, mean 3.8 cm from the temporal tip). The ECS-induced impairment probability was higher in the following tasks, listed in a descending order: spoken-word picture matching, picture naming, Kanji word reading, paragraph reading, spoken-verbal command, and Kana word reading. The anterior fusiform gyrus (FG), adjacent anterior inferior temporal gyrus (ITG), and the anterior end where FG and ITG fuse, were characterized by stimulation-induced impairment during visual and auditory tasks requiring verbal output or not, whereas the middle FG was characterized mainly by visual input. The parahippocampal gyrus was the least impaired of the three gyri in the basal temporal area. We propose that the BTLA has a functional gradient, with the anterior part involved in amodal semantic processing and the posterior part, especially the middle FG in unimodal semantic processing.

Learning of the same task subserved by substantially different mechanisms between patients with body dysmorphic disorder and healthy individuals.

It has remained unclear whether individuals with psychiatric disorders involving altered visual processing employ similar neuronal mechanisms during perceptual learning of a visual task. We investigated this question by training patients with body dysmorphic disorder, a psychiatric disorder characterized by distressing or impairing preoccupation with nonexistent or slight defects in one's physical appearance, and healthy controls on a visual detection task for human faces with low spatial frequency components. Brain activation during task performance was measured with functional magnetic resonance imaging before the beginning and after the end of behavioral training. Both groups of participants improved performance on the trained task to a similar extent. However, neuronal changes in the fusiform face area were substantially different between groups such that activation for low spatial frequency faces in the right fusiform face area increased after training in body dysmorphic disorder patients but decreased in controls. Moreover, functional connectivity between left and right fusiform face area decreased after training in patients but increased in controls. Our results indicate that neuronal mechanisms involved in perceptual learning of a face detection task differ fundamentally between body dysmorphic disorder patients and controls. Such different neuronal mechanisms in body dysmorphic disorder patients might reflect the brain's adaptations to altered functions imposed by the psychiatric disorder.

Atypical neural encoding of faces in individuals with autism spectrum disorder.

Individuals with autism spectrum disorder (ASD) experience pervasive difficulties in processing social information from faces. However, the behavioral and neural mechanisms underlying social trait judgments of faces in ASD remain largely unclear. Here, we comprehensively addressed this question by employing functional neuroimaging and parametrically generated faces that vary in facial trustworthiness and dominance. Behaviorally, participants with ASD exhibited reduced specificity but increased inter-rater variability in social trait judgments. Neurally, participants with ASD showed hypo-activation across broad face-processing areas. Multivariate analysis based on trial-by-trial face responses could discriminate participant groups in the majority of the face-processing areas. Encoding social traits in ASD engaged vastly different face-processing areas compared to controls, and encoding different social traits engaged different brain areas. Interestingly, the idiosyncratic brain areas encoding social traits in ASD were still flexible and context-dependent, similar to neurotypicals. Additionally, participants with ASD also showed an altered encoding of facial saliency features in the eyes and mouth. Together, our results provide a comprehensive understanding of the neural mechanisms underlying social trait judgments in ASD.

Somatic PDGFRB activating variants promote smooth muscle cell phenotype modulation in intracranial fusiform aneurysm.

BACKGROUND: The fusiform aneurysm is a nonsaccular dilatation affecting the entire vessel wall over a short distance. Although PDGFRB somatic variants have been identified in fusiform intracranial aneurysms, the molecular and cellular mechanisms driving fusiform intracranial aneurysms due to PDGFRB somatic variants remain poorly understood. METHODS: In this study, single-cell sequencing and immunofluorescence were employed to investigate the phenotypic changes in smooth muscle cells within fusiform intracranial aneurysms. Whole-exome sequencing revealed the presence of PDGFRB gene mutations in fusiform intracranial aneurysms. Subsequent immunoprecipitation experiments further explored the functional alterations of these mutated PDGFRB proteins. For the common c.1684 mutation site of PDGFRß, we established mutant smooth muscle cell lines and zebrafish models. These models allowed us to simulate the effects of PDGFRB mutations. We explored the major downstream cellular pathways affected by PDGFRBY562D mutations and evaluated the potential therapeutic effects of Ruxolitinib. RESULTS: Single-cell sequencing of two fusiform intracranial aneurysms sample revealed downregulated smooth muscle cell markers and overexpression of inflammation-related markers in vascular smooth muscle cells, which was validated by immunofluorescence staining, indicating smooth muscle cell phenotype modulation is involved in fusiform aneurysm. Whole-exome sequencing was performed on seven intracranial aneurysms (six fusiform and one saccular) and PDGFRB somatic mutations were detected in four fusiform aneurysms. Laser microdissection and Sanger sequencing results indicated that the PDGFRB mutations were present in smooth muscle layer. For the c.1684 (chr5: 149505131) site mutation reported many times, further cell experiments showed that PDGFRBY562D mutations promoted inflammatory-related vascular smooth muscle cell phenotype and JAK-STAT pathway played a crucial role in the process. Notably, transfection of PDGFRBY562D in zebrafish embryos resulted in cerebral vascular anomalies. Ruxolitinib, the JAK inhibitor, could reversed the smooth muscle cells phenotype modulation in vitro and inhibit the vascular anomalies in zebrafish induced by PDGFRB mutation. CONCLUSION: Our findings suggested that PDGFRB somatic variants played a role in regulating smooth muscle cells phenotype modulation in fusiform aneurysms and offered a potential therapeutic option for fusiform aneurysms.

Enhanced interhemispheric resting-state functional connectivity of the visual network is an early treatment response of paroxetine in patients with panic disorder.

This study aimed to detect alterations in interhemispheric interactions in patients with panic disorder (PD), determine whether such alterations could serve as biomarkers for the diagnosis and prediction of therapeutic outcomes, and map dynamic changes in interhemispheric interactions in patients with PD after treatment. Fifty-four patients with PD and 54 healthy controls (HCs) were enrolled in this study. All participants underwent clinical assessment and a resting-state functional magnetic resonance imaging scan at (i) baseline and (ii) after paroxetine treatment for 4 weeks. A voxel-mirrored homotopic connectivity (VMHC) indicator, support vector machine (SVM), and support vector regression (SVR) were used in this study. Patients with PD showed reduced VMHC in the fusiform, middle temporal/occipital, and postcentral/precentral gyri, relative to those of HCs. After treatment, the patients exhibited enhanced VMHC in the lingual gyrus, relative to the baseline data. The VMHC of the fusiform and postcentral/precentral gyri contributed most to the classification (accuracy = 87.04%). The predicted changes were accessed from the SVR using the aberrant VMHC as features. Positive correlations (p < 0.001) were indicated between the actual and predicted changes in the severity of anxiety. These findings suggest that impaired interhemispheric coordination in the cognitive-sensory network characterized PD and that VMHC can serve as biomarkers and predictors of the efficiency of PD treatment. Enhanced VMHC in the lingual gyrus of patients with PD after treatment implied that pharmacotherapy recruited the visual network in the early stages.

White matter connections of high-level visual areas predict cytoarchitecture better than category-selectivity in childhood, but not adulthood.

Ventral temporal cortex (VTC) consists of high-level visual regions that are arranged in consistent anatomical locations across individuals. This consistency has led to several hypotheses about the factors that constrain the functional organization of VTC. A prevailing theory is that white matter connections influence the organization of VTC, however, the nature of this constraint is unclear. Here, we test 2 hypotheses: (1) white matter tracts are specific for each category or (2) white matter tracts are specific to cytoarchitectonic areas of VTC. To test these hypotheses, we used diffusion magnetic resonance imaging to identify white matter tracts and functional magnetic resonance imaging to identify category-selective regions in VTC in children and adults. We find that in childhood, white matter connections are linked to cytoarchitecture rather than category-selectivity. In adulthood, however, white matter connections are linked to both cytoarchitecture and category-selectivity. These results suggest a rethinking of the view that category-selective regions in VTC have category-specific white matter connections early in development. Instead, these findings suggest that the neural hardware underlying the processing of categorical stimuli may be more domain-general than previously thought, particularly in childhood.

Fusiform nanoparticle boosts efficient genetic transformation in Sclerotinia sclerotiorum.

BACKGROUND: Sclerotinia sclerotiorum is a highly destructive phytopathogenic fungus that poses a significant threat to a wide array of crops. The current constraints in genetic manipulation techniques impede a thorough comprehension of its pathogenic mechanisms and the development of effective control strategies. RESULTS: Herein, we present a highly efficient genetic transformation system for S. sclerotiorum, leveraging the use of fusiform nanoparticles, which are synthesized with FeCl3 and 2,6-diaminopyrimidine (DAP). These nanoparticles, with an average longitude length of 59.00 nm and a positively charged surface, facilitate the direct delivery of exogenous DNA into the mycelial cells of S. sclerotiorum, as well as successful integration with stable expression. Notably, this system circumvents fungal protoplast preparation and tedious recovery processes, streamlining the transformation process considerably. Furthermore, we successfully employed this system to generate S. sclerotiorum strains with silenced oxaloacetate acetylhydrolase-encoding gene Ss-oah1. CONCLUSIONS: Our findings demonstrate the feasibility of using nanoparticle-mediated delivery as a rapid and reliable tool for genetic modification in S. sclerotiorum. Given its simplicity and high efficiency, it has the potential to significantly propel genetic research in filamentous fungi, offering new avenues for elucidating the intricacies of pathogenicity and developing innovative disease management strategies.

Functionally and structurally distinct fusiform face area(s) in over 1000 participants.

The fusiform face area (FFA) is a widely studied region causally involved in face perception. Even though cognitive neuroscientists have been studying the FFA for over two decades, answers to foundational questions regarding the function, architecture, and connectivity of the FFA from a large (N>1000) group of participants are still lacking. To fill this gap in knowledge, we quantified these multimodal features of fusiform face-selective regions in 1053 participants in the Human Connectome Project. After manually defining over 4,000 fusiform face-selective regions, we report five main findings. First, 68.76% of hemispheres have two cortically separate regions (pFus-faces/FFA-1 and mFus-faces/FFA-2). Second, in 26.69% of hemispheres, pFus-faces/FFA-1 and mFus-faces/FFA-2 are spatially contiguous, yet are distinct based on functional, architectural, and connectivity metrics. Third, pFus-faces/FFA-1 is more face-selective than mFus-faces/FFA-2, and the two regions have distinct functional connectivity fingerprints. Fourth, pFus-faces/FFA-1 is cortically thinner and more heavily myelinated than mFus-faces/FFA-2. Fifth, face-selective patterns and functional connectivity fingerprints of each region are more similar in monozygotic than dizygotic twins and more so than architectural gradients. As we share our areal definitions with the field, future studies can explore how structural and functional features of these regions will inform theories regarding how visual categories are represented in the brain.

Electrocorticography reveals the dynamics of famous voice responses in human fusiform gyrus.

Voice and face processing occur through convergent neural systems that facilitate speaker recognition. Neuroimaging studies suggest that familiar voice processing engages early visual cortex, including the bilateral fusiform gyrus (FG) on the basal temporal lobe. However, what role the FG plays in voice processing and whether it is driven by bottom-up or top-down mechanisms is unresolved. In this study we directly examined neural responses to famous voices and faces in human FG with direct cortical surface recordings (electrocorticography) in epilepsy surgery patients. We tested the hypothesis that neural populations in human FG respond to famous voices and investigated the temporal properties of voice responses in FG. Recordings were acquired from five adult participants during a person identification task using visual and auditory stimuli from famous speakers (U.S. Presidents Barack Obama, George W. Bush, and Bill Clinton). Patients were presented with images of presidents or clips of their voices and asked to identify the portrait/speaker. Our results demonstrate that a subset of face-responsive sites in and near FG also exhibit voice responses that are both lower in magnitude and delayed (300-600 ms) compared with visual responses. The dynamics of voice processing revealed by direct cortical recordings suggests a top-down feedback-mediated response to famous voices in FG that may facilitate speaker identification.NEW & NOTEWORTHY Interactions between auditory and visual cortices play an important role in person identification, but the dynamics of these interactions remain poorly understood. We performed direct brain recordings of fusiform face cortex in human epilepsy patients performing a famous voice naming task, revealing the dynamics of famous voice processing in human fusiform face cortex. The findings support a model of top-down interactions from auditory to visual cortex to facilitate famous voice recognition.

White matter microstructure in face and body networks predicts facial expression and body posture perception across development.

Facial expression and body posture recognition have protracted developmental trajectories. Interactions between face and body perception, such as the influence of body posture on facial expression perception, also change with development. While the brain regions underpinning face and body processing are well-defined, little is known about how white-matter tracts linking these regions relate to perceptual development. Here, we obtained complementary diffusion magnetic resonance imaging (MRI) measures (fractional anisotropy [FA], spherical mean Sµ ), and a quantitative MRI myelin-proxy measure (R1), within white-matter tracts of face- and body-selective networks in children and adolescents and related these to perceptual development. In tracts linking occipital and fusiform face areas, facial expression perception was predicted by age-related maturation, as measured by Sµ and R1, as well as age-independent individual differences in microstructure, captured by FA and R1. Tract microstructure measures linking posterior superior temporal sulcus body region with anterior temporal lobe (ATL) were related to the influence of body on facial expression perception, supporting ATL as a site of face and body network convergence. Overall, our results highlight age-dependent and age-independent constraints that white-matter microstructure poses on perceptual abilities during development and the importance of complementary microstructural measures in linking brain structure and behaviour.

Clinical presentation, outcomes, and threshold for repair by sex in degenerative saccular vs fusiform aneurysms in the descending thoracic aorta.

OBJECTIVE: Saccular-shaped thoracic aortic aneurysms (TAAs) are often treated at smaller diameters compared with fusiform TAAs, despite a lack of strong clinical evidence to support this practice. The aim of this study was to examine differences in presentation, treatment, and outcomes between saccular TAAs and fusiform TAAs in the descending thoracic aorta. We also examined the need for sex-specific treatment thresholds for TAAs. METHODS: All Vascular Quality Initiative (VQI) patients undergoing thoracic endovascular aneurysm repair (TEVAR) for degenerative TAAs in the descending thoracic aorta from 2012 through 2022 were reviewed. Patients were stratified by urgency: emergent/urgent vs elective repairs (ruptured/symptomatic). Demographics, comorbidities, anatomical/procedural characteristics, and outcomes for fusiform TAAs and saccular TAAs were compared. Cumulative distribution curves were used to plot the proportion of patients who underwent emergent/urgent repair according to sex-stratified aortic diameter. RESULTS: Among 655 emergent/urgent TEVARs, 37% were performed for saccular TAAs, whereas among 1352 elective TEVARs, 35% had saccular TAA morphology. Compared with fusiform TAAs, saccular TAAs more frequently underwent emergent/urgent (ruptured/symptomatic) TEVAR below the repair threshold in both females (<50 mm: 38% vs 10%; relative risk, 3.39; 95% confidence interval [CI], 2.04-5.70; P < .001), and males (<55 mm: 47% vs 21%; relative risk, 2.26; 95% CI, 1.60-3.18; P < .001). Moreover, among patients with emergent/urgent fusiform TAAs, females presented at smaller diameters compared with males, whereas there was no difference in preoperative aneurysm diameter among patients with saccular TAAs. Regarding outcomes, emergent/urgent treated saccular TAAs had similar postoperative outcomes and 5-year mortality compared with fusiform TAAs. Nevertheless, in the elective cohort, patients with saccular TAAs had similar postoperative mortality compared with those with fusiform TAAs, but a lower rate of postoperative spinal cord ischemia (0.7% vs 3.2%; P = .010). Furthermore, patients with saccular TAAs had a higher rate of 5-year mortality compared with their fusiform counterparts (23% vs 17%; hazard ratio, 1.53; 95% CI, 1.12-2.10; P = .010). CONCLUSIONS: Patients with saccular TAAs underwent emergent/urgent TEVAR at smaller diameters than those with fusiform TAAs, supporting current clinical practice guideline recommendations that saccular TAAs warrant treatment at smaller diameters. Furthermore, these data support a sex-specific treatment threshold for patients with fusiform TAAs, but not for those with saccular TAAs. Although there were no differences in outcomes following TEVAR between morphologies in the emergent/urgent cohort, patients with saccular TAAs who were treated electively were associated with higher 5-year mortality compared with those with fusiform TAAs.

Neurobiological correlates and attenuated positive social intention attribution during laughter perception associated with degree of autistic traits.

Laughter plays an important role in group formation, signaling social belongingness by indicating a positive or negative social intention towards the receiver. In adults without autism, the intention of laughter can be correctly differentiated without further contextual information. In autism spectrum disorder (ASD), however, differences in the perception and interpretation of social cues represent a key characteristic of the disorder. Studies suggest that these differences are associated with hypoactivation and altered connectivity among key nodes of the social perception network. How laughter, as a multimodal nonverbal social cue, is perceived and processed neurobiologically in association with autistic traits has not been assessed previously. We investigated differences in social intention attribution, neurobiological activation, and connectivity during audiovisual laughter perception in association with the degree of autistic traits in adults [N = 31, Mage (SD) = 30.7 (10.0) years, nfemale = 14]. An attenuated tendency to attribute positive social intention to laughter was found with increasing autistic traits. Neurobiologically, autistic trait scores were associated with decreased activation in the right inferior frontal cortex during laughter perception and with attenuated connectivity between the bilateral fusiform face area with bilateral inferior and lateral frontal, superior temporal, mid-cingulate and inferior parietal cortices. Results support hypoactivity and hypoconnectivity during social cue processing with increasing ASD symptoms between socioemotional face processing nodes and higher-order multimodal processing regions related to emotion identification and attribution of social intention. Furthermore, results reflect the importance of specifically including signals of positive social intention in future studies in ASD.

Preference for animate domain sounds in the fusiform gyrus of blind individuals is modulated by shape-action mapping.

In high-level visual areas in the human brain, preference for inanimate objects is observed regardless of stimulation modality (visual/auditory/tactile) and individual's visual experience (sighted/blind) whereas preference for animate entities seems robust mainly in the visual modality. Here, we test a hypothesis explaining this domain difference: Object representations can be activated through nonvisual stimulation when their shapes are systematically related to action system representations, a quality typical of most inanimate objects but of only specific animate entities. We studied functional magnetic resonance imaging activations in congenitally blind and sighted individuals listening to animal, object, and human sounds. In blind individuals, the typical location of the fusiform face area preferentially responded to human facial expression sounds clearly related to specific facial actions and resulting face shapes but not to speech or animal sounds. No univariate preference for any sound category was observed in the fusiform gyrus in sighted individuals, but the expected multivoxel effects were present. We conclude that nonvisual signals can activate shape representations of those stimuli-inanimate or animate-for which shape and action computations are transparently related. However, absence of potentially competing visual inputs seems necessary for this effect to be clearly detectable in the case of animate representation.

Impaired Filtering and Hyperfocusing: Neural Evidence for Distinct Selective Attention Abnormalities in People with Schizophrenia.

Although schizophrenia is classically thought to involve impaired attentional filtering, people with schizophrenia (PSZ) exhibit a more intense and more exclusive attentional focus than healthy control subjects (HCS) in many tasks. To resolve this contradiction, this functional magnetic resonance imaging study tested the impact of attentional control demands on the modulation of stimulus-induced activation in the fusiform face area and parahippocampal place area when participants (43 PSZ and 43 HCS) were looking for a target face versus house. Stimuli were presented individually, or as face-house overlays that challenged attentional control. Responses were slower for house than face stimuli and when prioritizing houses over faces in overlays, suggesting a difference in salience. Blood-oxygen-level-dependent activity reflected poorer attentional selectivity in PSZ than HCS when attentional control was challenged most, that is, when stimuli were overlaid and the task required detecting the lower-salience house target. By contrast, attentional selectivity was exaggerated in PSZ when control was challenged least, that is, when stimuli were presented sequentially and the task required detecting the higher-salience face target. These findings are consistent with 2 distinct attentional abnormalities in schizophrenia leading to impaired and exaggerated selection under different conditions: attentional control deficits, and hyperfocusing once attention has been directed toward a stimulus.

Fusiform aneurysms of anterior cerebral artery: center experience and systematic literature review.

Fusiform aneurysms of the anterior cerebral artery (ACA) are uncommon, and the natural history of this entity is poorly characterized. Along with our center experience, we conducted a systematic literature review to help shed light on the clinical course of ACA fusiform aneurysms. We queried our institutional database to identify cases with fusiform aneurysms of ACA. In addition, following the PRISMA algorithm, we identified all reported cases published in the English literature from the inception of PubMed until December 2022. We categorized clinical presentations into three categories: (i) traumatic/iatrogenic, (ii) spontaneous symptomatic ruptured/unruptured, and (iii) spontaneous asymptomatic aneurysms. We utilized descriptive statistics. We identified seven cases from our center along with 235 patients from published literature. Blunt trauma was responsible for the development of 19 aneurysms. Sixty-three percent of these aneurysms tend to rupture within 2 weeks from the initial trauma, and despite treatment, only 74% of these patients had good clinical outcomes. Spontaneous symptomatic presentation occurred in 207 patients and was often associated with previous/concomitant ACA dissection. Subarachnoid hemorrhage from ruptured aneurysms was the most common presentation. Spontaneous symptomatic fusiform aneurysm is rapidly evolving lesions, and treatment is necessary. Three of our own cases were treated with an endovascular flow diverter (pipeline) stenting with good outcomes. Spontaneous asymptomatic aneurysms were reported in nine patients. These lesions are often associated with other vascular abnormalities. Treatment included surgical clipping with good clinical outcomes. Instead, four patients from our center database were managed conservatively with equally good outcomes. Our study demonstrates good clinical outcomes when fusiform aneurysms of ACA, especially when symptomatic, are treated promptly with either reconstructive or deconstructive therapies.

Visual experience is not necessary for the development of face-selectivity in the lateral fusiform gyrus.

The fusiform face area responds selectively to faces and is causally involved in face perception. How does face-selectivity in the fusiform arise in development, and why does it develop so systematically in the same location across individuals? Preferential cortical responses to faces develop early in infancy, yet evidence is conflicting on the central question of whether visual experience with faces is necessary. Here, we revisit this question by scanning congenitally blind individuals with fMRI while they haptically explored 3D-printed faces and other stimuli. We found robust face-selective responses in the lateral fusiform gyrus of individual blind participants during haptic exploration of stimuli, indicating that neither visual experience with faces nor fovea-biased inputs is necessary for face-selectivity to arise in the lateral fusiform gyrus. Our results instead suggest a role for long-range connectivity in specifying the location of face-selectivity in the human brain.

Connectivity at the origins of domain specificity in the cortical face and place networks.

It is well established that the adult brain contains a mosaic of domain-specific networks. But how do these domain-specific networks develop? Here we tested the hypothesis that the brain comes prewired with connections that precede the development of domain-specific function. Using resting-state fMRI in the youngest sample of newborn humans tested to date, we indeed found that cortical networks that will later develop strong face selectivity (including the "proto" occipital face area and fusiform face area) and scene selectivity (including the "proto" parahippocampal place area and retrosplenial complex) by adulthood, already show domain-specific patterns of functional connectivity as early as 27 d of age (beginning as early as 6 d of age). Furthermore, we asked how these networks are functionally connected to early visual cortex and found that the proto face network shows biased functional connectivity with foveal V1, while the proto scene network shows biased functional connectivity with peripheral V1. Given that faces are almost always experienced at the fovea, while scenes always extend across the entire periphery, these differential inputs may serve to facilitate domain-specific processing in each network after that function develops, or even guide the development of domain-specific function in each network in the first place. Taken together, these findings reveal domain-specific and eccentricity-biased connectivity in the earliest days of life, placing new constraints on our understanding of the origins of domain-specific cortical networks.

Focusing on the Emerging Role of Kainate Receptors in the Dorsal Cochlear Nucleus (DCN) and Cerebellum.

Mammals have a dorsal cochlear nucleus (DCN), which is thought to be a cerebellum-like structure with similar features in terms of structure and microcircuitry to the cerebellum. Both the DCN and cerebellum perform their functions depending on synaptic and neuronal networks mediated by various glutamate receptors. Kainate receptors (KARs) are one class of the glutamate receptor family and are strongly expressed in the hippocampus, the cerebellum, and cerebellum-like structures. The cellular distribution and the potential role of KARs in the hippocampus have been extensively investigated. However, the cellular distribution and the potential role of KARs in cerebellum-like structures, including the DCN and cerebellum, are poorly understood. In this review, we summarize the similarity between the DCN and cerebellum at the levels of structure, circuitry, and cell type as well as the investigations referring to the expression patterns of KARs in the DCN and cerebellum according to previous studies. Recent studies on the role of KARs have shown that KARs mediate a bidirectional modulatory effect at parallel fiber (PF)-Purkinje cell (PC) synapses in the cerebellum, implying insights into their roles in cerebellum-like structures, including the DCN, that remain to be explored in the coming years.

Face-Selective Units in Human Ventral Temporal Cortex Reactivate during Free Recall.

Research in functional neuroimaging has suggested that category-selective regions of visual cortex, including the ventral temporal cortex (VTC), can be reactivated endogenously through imagery and recall. Face representation in the monkey face-patch system has been well studied and is an attractive domain in which to explore these processes in humans. The VTCs of 8 human subjects (4 female) undergoing invasive monitoring for epilepsy surgery were implanted with microelectrodes. Most (26 of 33) category-selective units showed specificity for face stimuli. Different face exemplars evoked consistent and discriminable responses in the population of units sampled. During free recall, face-selective units preferentially reactivated in the absence of visual stimulation during a 2 s window preceding face recall events. Furthermore, we show that in at least 1 subject, the identity of the recalled face could be predicted by comparing activity preceding recall events to activity evoked by visual stimulation. We show that face-selective units in the human VTC are reactivated endogenously, and present initial evidence that consistent representations of individual face exemplars are specifically reactivated in this manner.SIGNIFICANCE STATEMENT The role of "top-down" endogenous reactivation of native representations in higher sensory areas is poorly understood in humans. We conducted the first detailed single-unit survey of ventral temporal cortex (VTC) in human subjects, showing that, similarly to nonhuman primates, humans encode different faces using different rate codes. Then, we demonstrated that, when subjects recalled and imagined a given face, VTC neurons reactivated with the same rate codes as when subjects initially viewed that face. This suggests that the VTC units not only carry durable representations of faces, but that those representations can be endogenously reactivated via "top-down" mechanisms.

Early visual exposure primes future cross-modal specialization of the fusiform face area in tactile face processing in the blind.

The fusiform face area (FFA) is a core cortical region for face information processing. Evidence suggests that its sensitivity to faces is largely innate and tuned by visual experience. However, how experience in different time windows shape the plasticity of the FFA remains unclear. In this study, we investigated the role of visual experience at different time points of an individual's early development in the cross-modal face specialization of the FFA. Participants (n = 74) were classified into five groups: congenital blind, early blind, late blind, low vision, and sighted control. Functional magnetic resonance imaging data were acquired when the participants haptically processed carved faces and other objects. Our results showed a robust and highly consistent face-selective activation in the FFA region in the early blind participants, invariant to size and level of abstraction of the face stimuli. The cross-modal face activation in the FFA was much less consistent in other groups. These results suggest that early visual experience primes cross-modal specialization of the FFA, and even after the absence of visual experience for more than 14 years in early blind participants, their FFA can engage in cross-modal processing of face information.