Superior Temporal Sulcus Research Articles

Neural correlates of individual differences in multimodal emotion recognition ability

Studies have reported substantial variability in emotion recognition ability (ERA) – an important social skill – but possible neural underpinnings for such individual differences are not well understood. This functional magnetic resonance imaging (fMRI) study investigated neural responses during emotion recognition in young adults (N = 49) who were selected for inclusion based on their performance (high or low) during previous testing of ERA. Participants were asked to judge brief video recordings in a forced-choice emotion recognition task, wherein stimuli were presented in visual, auditory and multimodal (audiovisual) blocks. Emotion recognition rates during brain scanning confirmed that individuals with high (vs low) ERA received higher accuracy for all presentation blocks. fMRI-analyses focused on key regions of interest (ROIs) involved in the processing of multimodal emotion expressions, based on previous meta-analyses. In neural response to emotional stimuli contrasted with neutral stimuli, individuals with high (vs low) ERA showed higher activation in the following ROIs during the multimodal condition: right middle superior temporal gyrus (mSTG), right posterior superior temporal sulcus (PSTS), and right inferior frontal cortex (IFC). Overall, results suggest that individual variability in ERA may be reflected across several stages of decisional processing, including extraction (mSTG), integration (PSTS) and evaluation (IFC) of emotional information.

Association of β-Amyloid, Microglial Activation, Cortical Thickness, and Metabolism in Older Adults Without Dementia.

Plasma β-amyloid42 (Aβ42)/Aβ40 levels have shown promise in identifying Aβ-PET positive individuals. This study explored the concordance and discordance of plasma Aβ42/Aβ40 positivity (Plasma±) with CSF Aβ42/Aβ40 positivity (CSF±) and Aβ-PET positivity (PET±) in older adults without dementia. Associations of Aβ deposition, cortical thickness, glucose metabolism, and microglial activation were also investigated. We selected participants without dementia who had concurrent plasma Aβ42/Aβ40 and Aβ-PET scans from the Alzheimer's Disease Neuroimaging Initiative cohort. Participants were categorized into Plasma±/PET± based on thresholds of composite 18F-florbetapir (FBP) standardized uptake value ratio (SUVR) ≥1.11 and plasma Aβ42/Aβ40 ≤0.1218. Aβ-PET-negative individuals were further divided into Plasma±/CSF± (CSF Aβ42/Aβ40 ≤0.138), and the concordance and discordance of Aβ42/Aβ40 in the plasma and CSF were investigated. Baseline and slopes of regional FBP SUVR were compared among Plasma±/PET± groups, and associations of regional FBP SUVR, FDG SUVR, cortical thickness, and CSF soluble Triggering Receptor Expressed on Myeloid Cell 2 (sTREM2) levels were analyzed. One hundred eighty participants (mean age 72.7 years, 51.4% female, 96 cognitively unimpaired, and 84 with mild cognitive impairment) were included. We found that the proportion of Plasma+/PET- individuals was 6.14 times higher (odds ratio (OR) = 6.143, 95% confidence interval (CI) 2.740-16.185, p < 0.001) than that of Plasma-/PET+ individuals, and Plasma+/CSF- individuals showed 8.5 times larger percentage (OR = 8.5, 95% CI: 3.031-32.974, p < 0.001) than Plasma-/CSF+ individuals in Aβ-PET-negative individuals. Besides, Plasma+/PET- individuals exhibited faster (p < 0.05) Aβ accumulation predominantly in bilateral banks of superior temporal sulcus (BANKSSTS) and supramarginal, and superior parietal cortices compared with Plasma-/PET- individuals, despite no difference in baseline FBP SUVRs. In Plasma+/PET+ individuals, higher CSF sTREM2 levels correlated with slower BANKSSTS Aβ accumulation (standardized β (βstd) = -0.418, 95% CI -0.681 to -0.154, p = 0.002). Conversely, thicker cortical thickness and higher glucose metabolism in supramarginal and superior parietal cortices were associated with faster (p < 0.05) CSF sTREM2 increase in Plasma+/PET- individuals rather than in Plasma+/PET+ individuals. These findings suggest that plasma Aβ42/Aβ40 abnormalities may predate CSF Aβ42/Aβ40 and Aβ-PET abnormalities. Higher sTREM2-related microglial activation is linked to thicker cortical thickness and higher metabolism in early amyloidosis stages but tends to mitigate Aβ accumulation primarily at relatively advanced stages.

Dynamic brain communication underwriting face pareidolia

Face pareidolia is a tendency to seeing faces in nonface images that reflects high tuning to a face scheme. Yet, studies of the brain networks underwriting face pareidolia are scarce. Here, we examined the time course and dynamic topography of gamma oscillatory neuromagnetic activity while administering a task with nonface images resembling a face. Images were presented either with canonical orientation or with display inversion that heavily impedes face pareidolia. At early processing stages, the peaks in gamma activity (40 to 45 Hz) to images either triggering or not face pareidolia originate mainly from the right medioventral and lateral occipital cortices, rostral and caudal cuneus gyri, and medial superior occipital gyrus. Yet, the difference occurred at later processing stages in the high-frequency range of 80 to 85 Hz over a set of the areas constituting the social brain. The findings speak rather for a relatively late neural network playing a key role in face pareidolia. Strikingly, a cutting-edge analysis of brain connectivity unfolding over time reveals mutual feedforward and feedback intra- and interhemispheric communication not only within the social brain but also within the extended large-scale network of down- and upstream regions. In particular, the superior temporal sulcus and insula strongly engage in communication with other brain regions either as signal transmitters or recipients throughout the whole processing of face-pareidolia images.

A chronometric study of the posterior cerebellum’s function in emotional processing

The posterior cerebellum is a recently discovered hub of the affective and social brain, with different subsectors contributing to different social functions. However, very little is known about when the posterior cerebellum plays a critical role in social processing. Due to its location and anatomy, it has been difficult to use traditional approaches to directly study the chronometry of the cerebellum. To address this gap in cerebellar knowledge, here we investigated the causal contribution of the posterior cerebellum to social processing using a chronometric transcranial magnetic stimulation (TMS) approach. We show that the posterior cerebellum is recruited at an early stage of emotional processing (starting from 100ms after stimulus onset), simultaneously with the posterior superior temporal sulcus (pSTS), a key node of the social brain. Moreover, using a condition-and-perturb TMS approach, we found that the recruitment of the pSTS in emotional processing is dependent on cerebellar activation. Our results are the first to shed light on chronometric aspects of cerebellar function and its causal functional connectivity with other nodes of the social brain.

Multivariate associations between psychiatric drug intake and grey matter volume changes in individuals at early stages of psychosis and depression

IntroductionPsychiatric drugs, including antipsychotics and antidepressants, are widely prescribed, even in young and adolescent populations at early or subthreshold disease stages. However, their impact on brain structure remains elusive. Elucidating the relationship between psychotropic medication and structural brain changes could enhance the understanding of the potential benefits and risks associated with such treatment.Objectives Investigation of the associations between psychiatric drug intake and longitudinal grey matter volume (GMV) changes in a transdiagnostic sample of young individuals at early stages of psychosis or depression using an unbiased data-driven approach.Methods The study sample comprised 247 participants (mean [SD] age = 25.06 [6.13] years, 50.61% male), consisting of young, minimally medicated individuals at clinical high-risk states for psychosis, individuals with recent-onset depression or psychosis, and healthy control individuals. Structural magnetic resonance imaging was used to obtain whole-brain voxel-wise GMV for all participants at two timepoints (mean [SD] time between scans = 11.15 [4.93] months). The multivariate sparse partial least squares (SPLS) algorithm (Monteiro et al. JNMEDT 2016; 271:182-194) was embedded in a nested cross-validation framework to identify parsimonious associations between the cumulative intake of psychiatric drugs, including commonly prescribed antipsychotics and antidepressants, and change in GMV between both timepoints, while additionally factoring in age, sex, and diagnosis. Furthermore, we correlated the retrieved SPLS results to personality domains (NEO-FFI) and childhood trauma (CTQ).ResultsSPLS analysis revealed significant associations between the antipsychotic classes of benzamides, butyrophenones and thioxanthenes and longitudinal GMV decreases in cortical regions including the insula, posterior superior temporal sulcus as well as cingulate, postcentral, precentral, orbital and frontal gyri (Figure 1A-C). These brain regions corresponded most closely to the dorsal and ventral attention, somatomotor, salience and default network (Figure 1D). Furthermore, the medication signature was negatively associated with the personality domains extraversion, agreeableness and conscientiousness and positively associated with the CTQ domains emotional and physical neglect.Image:ConclusionsPsychiatric drug intake over a period of one year was linked to distinct GMV reductions in key cortical hubs. These patterns were already visible in young individuals at early or subthreshold stages of mental illness and were further linked to childhood neglect and personality traits. Hence, a better and more in-depth understanding of the structural brain implications of medicating young and adolescent individuals might lead to more cautious, sustainable and targeted treatment strategies.Disclosure of InterestNone Declared

Cognitive Neuroscience of Autism Spectrum Disorder: The Neurobiology of Empathic Process

IntroductionAutism Spectrum Disorders (ASD) is diagnosed when an individual displays irregularity in three key domains: social development, communication, and repetitive behavior/obsessive interests.The theory of mind-blindness in ASD suggests that individuals on the autism spectrum exhibit deficiencies in the typical empathic process, relative to their mental age.Empathy comprises two primary components: firstly, the capacity to attribute mental states to both oneself and others, and secondly, experiencing an emotional response that aligns with the mental state of the other person.ObjectivesThis study aimed to synthetase the latest evidence about the neuropsychiatric basis of empathy in ASD.MethodsA review was conducted, drawing on reputable sources (PubMed and Web of Science databases).Results A neural basis of empathy has built on a model first proposed by Brothers. It was suggested that social intelligence was a function of three regions: the amygdala, the orbitofrontal and medial frontal cortex, and the superior temporal sulcus and gyrus - the “social brain”. Abnormalities in autism have been found in the amygdala, the orbito and the medial frontal cortex.Amygdala has been implicated primarily in fear perception of facial expressions, as well as in the recognition of other emotions such as sadness and “social” emotions. In addition to fear perception, the amygdala has also been implicated in related processes including eye gaze, affective memory, olfactory learning, and social judgment.To date, findings on amygdala structure in autism have been mixed, with studies indicating reduced and increased volumes, as well as nonsignificant differences.ConclusionsASD is one of the most heterogeneous neurodevelopmental disorders, and cognitive theories as well as structural findings have linked likely frontal lobe abnormalities to the social and cognitive profiles of autism.Future studies may elucidate existing data by taking advantage of new and infrequently used data acquisition technologies such as Transcranial Magnetic Stimulation.Disclosure of InterestNone Declared

Altered Cortical Gyrification Morphology in Nonsucidal Self-injury

IntroductionNonsuicidal self-injury (NSSI) is defined as deliberate and direct damage to one’s body tissues without any suicidal intent. NSSI is now recognized as a major risk factor for suicide and is prevalent among adolescents, with prevalence rates ranging from 7.5% to 46.5%, leading to increased interest in the pathophysiology of NSSI. This study aimed to examine cortical gyrification morphology, a neurobiological index of cortical folding and patterning, among unmedicated individuals with NSSI, which is prevalent in adolescents and young adults.Objectives The main objective of this study is to compare cortical morphological abnormalities between individuals with NSSI and controls in terms of the local gyrification index (LGI), the ratio of the smooth cortical surface area at each vertex to the corresponding sulcal folds. In addition, we hypothesized that the LGI, a stable neurodevelopmental marker of cortical and subcortical circuit intergrity, would correlate with clinical measures in youth with NSSI.Methods A total of 101 individuals with NSSI and 100 age-, gender-, and handedness-matched controls completed self-report questionnaires and structural magnetic resonance imaging (MRI) data were acquired on a 3T Siemens scanner. A surface-based analysis was conducted using the Computational Anatomy Toolbox (CAT12) in Statistical Parametric Mapping (SPM12). Partial correlation analysis was also performed using R software to investigate the association between the LGI values extracted from the region of interest (ROI) and clinical symptoms, including depression, anxiety, emotion dysregulation, and anhedonia in individuals with NSSI.ResultsIndividuals with NSSI showed significantly increased LGI in the right insula sulcus and left superior temporal sulcus (STS), along with decreased LGI in the right calcarine and left superior parietal sulcus (SPS), compared to controls (5000 permutation correction, threshold-free cluster enhancement with a threshold of p &lt; .05). In addition, higher LGI in left STS was correlated with greater scores of the Beck Anxiety Inventory (r = 0.22, p &lt; .05) and of the Impulse Control Difficulties subscale of the Difficulties in Emotion Regulation Scale (r = 0.34, p &lt; .001). Conversely, reduced LGI of the right calcarine was associated with a higher score on the Anhedonia subscale of the Beck Depression Inventory (r = -0.23, p &lt; .05) within individuals with NSSI.ConclusionsThis study identified hypergyria in the right insular and left STS and hypogyria in the right calcarine and left SPS in individuals with NSSI. The former pattern was associated with anxiety and impulse control difficulties, and the latter was with anhedonia. This study is the first to alter distinct neurodevelopmental patterns of local gyrification and their correlations with clinical manifestations in individuals with NSSI.Disclosure of InterestNone Declared

355 Connecting computational models of reading to the brain in post-stroke alexia

OBJECTIVES/GOALS: Many left hemisphere stroke survivors have a reading disorder (alexia), which is experienced as decreasing well-being. Therapies produce inconsistent results, demonstrating a need for treatment response predictors. We are investigating neural correlates of reading computational models to identify biomarkers to improve therapeutic outcomes. METHODS/STUDY POPULATION: Artificial neural network models of reading, mapping between orthography (visual word form), phonology (auditory word form), and semantics (word meaning), are trained to read single words at a healthy, adult capacity. The models are independently damaged to reflect the individual orthography-to-semantics, semantics-to-phonology, and orthography-to-phonology deficits of a sample of left hemisphere stroke survivors (n = 85). These deficits are measured with cognitive tests assessing the intactness of mappings between representations. Model damage is enacted by removing percentages of the connections between representations. For each type of deficit, the percentages of links removed are entered into a voxel-based lesion symptom mapping analysis to identify areas of cortex associated with that mapping. RESULTS/ANTICIPATED RESULTS: We anticipate that the neural correlates of model layers will be localized to a mostly left-lateralized network. Increased damage to the links between semantics and phonology in the model will likely be related to lesions involving the left posterior superior temporal sulcus and inferior frontal gyrus (IFG). Damaged orthography-to-semantic links will be related to the left fusiform gyrus (FG) and IFG. Finally, damage to the orthography-to-phonology links will be related to the left FG and superior temporal gyrus. DISCUSSION/SIGNIFICANCE: Mapping components of language models onto the brain will improve our understanding of the neural networks supporting language processing. Identifying these neural correlates may also produce biomarkers that can be used in predicting reading impairment at the acute stage or optimizing therapy in the chronic stage of stroke.

Visual perception of highly memorable images is mediated by a distributed network of ventral visual regions that enable a late memorability response.

Behavioral and neuroscience studies in humans and primates have shown that memorability is an intrinsic property of an image that predicts its strength of encoding into and retrieval from memory. While previous work has independently probed when or where this memorability effect may occur in the human brain, a description of its spatiotemporal dynamics is missing. Here, we used representational similarity analysis (RSA) to combine functional magnetic resonance imaging (fMRI) with source-estimated magnetoencephalography (MEG) to simultaneously measure when and where the human cortex is sensitive to differences in image memorability. Results reveal that visual perception of High Memorable images, compared to Low Memorable images, recruits a set of regions of interest (ROIs) distributed throughout the ventral visual cortex: a late memorability response (from around 300 ms) in early visual cortex (EVC), inferior temporal cortex, lateral occipital cortex, fusiform gyrus, and banks of the superior temporal sulcus. Image memorability magnitude results are represented after high-level feature processing in visual regions and reflected in classical memory regions in the medial temporal lobe (MTL). Our results present, to our knowledge, the first unified spatiotemporal account of visual memorability effect across the human cortex, further supporting the levels-of-processing theory of perception and memory.

Brain mechanisms involved in the perception of emotional gait: A combined magnetoencephalography and virtual reality study.

Brain processes associated with emotion perception from biological motion have been largely investigated using point-light displays that are devoid of pictorial information and not representative of everyday life. In this study, we investigated the brain signals evoked when perceiving emotions arising from body movements of virtual pedestrians walking in a community environment. Magnetoencephalography was used to record brain activation in 21 healthy young adults discriminating the emotional gaits (neutral, angry, happy) of virtual male/female pedestrians. Event-related responses in the posterior superior temporal sulcus (pSTS), fusiform body area (FBA), extrastriate body area (EBA), amygdala (AMG), and lateral occipital cortex (Occ) were examined. Brain signals were characterized by an early positive peak (P1;∼200ms) and a late positive potential component (LPP) comprising of an early (400-600ms), middle (600-1000ms) and late phase (1000-1500ms). Generalized estimating equations revealed that P1 amplitude was unaffected by emotion and gender of pedestrians. LPP amplitude showed a significant emotion X phase interaction in all regions of interest, revealing i) an emotion-dependent modulation starting in pSTS and Occ, followed by AMG, FBA and EBA, and ii) generally enhanced responses for angry vs. other gait stimuli in the middle LPP phase. LPP also showed a gender X phase interaction in pSTS and Occ, as gender affected the time course of the response to emotional gait. Present findings show that brain activation within areas associated with biological motion, form, and emotion processing is modulated by emotional gait stimuli rendered by virtual simulations representative of everyday life.

The role of preSMA and STS in face recognition: A transcranial magnetic stimulation (TMS) study

Current models propose that facial recognition is mediated by two independent yet interacting anatomo-functional systems: one processing facial features mainly mediated by the Fusiform Face Area and the other involved in the extraction of dynamic information from faces, subserved by Superior Temporal Sulcus (STS). Also, the pre-Supplementary Motor Area (pre-SMA) is implicated in facial expression processing as it is involved in its motor mimicry. However, the literature only shows evidence of the implication of STS and preSMA for facial expression recognition, without relating it to face recognition. In addition, the literature shows a facilitatory role of facial motion in the recognition of unfamiliar faces, particularly for poor recognizers. The present study aimed at studying the role of STS and preSMA in unfamiliar face recognition in people with different face recognition skills. 34 healthy participants received repetitive transcranial magnetic stimulation over the right posterior STS, pre-SMA and as sham during a task of matching of faces encoded through: facial expression, rigid head movement or as static (i.e., absence of any facial or head motion). All faces were represented without emotional content. Results indicate that STS has a direct role in recognizing identities through rigid head movement and an indirect role in facial expression processing. This dissociation represents a step forward with respect to current face processing models suggesting that different types of motion involve separate brain and cognitive processes. PreSMA interacts with face recognition skills, increasing the performance of poor recognizers and decreasing that of good recognizers in all presentation conditions. Together, the results suggest the use of at least partially different mechanisms for face recognition in poor and good recognizers and a different role of STS and preSMA in face recognition.

Neural Representations of Observed Interpersonal Synchrony/Asynchrony in the Social Perception Network.

The visual perception of individuals is thought to be mediated by a network of regions in the occipitotemporal cortex that supports specialized processing of faces, bodies, and actions. In comparison, we know relatively little about the neural mechanisms that support the perception of multiple individuals and the interactions between them. The present study sought to elucidate the visual processing of social interactions by identifying which regions of the social perception network represent interpersonal synchrony. In an fMRI study with 32 human participants (26 female, 6 male), we used multivoxel pattern analysis to investigate whether activity in face-selective, body-selective, and interaction-sensitive regions across the social perception network supports the decoding of synchronous versus asynchronous head-nodding and head-shaking. Several regions were found to support significant decoding of synchrony/asynchrony, including extrastriate body area (EBA), face-selective and interaction-sensitive mid/posterior right superior temporal sulcus, and occipital face area. We also saw robust cross-classification across actions in the EBA, suggestive of movement-invariant representations of synchrony/asynchrony. Exploratory whole-brain analyses also identified a region of the right fusiform cortex that responded more strongly to synchronous than to asynchronous motion. Critically, perceiving interpersonal synchrony/asynchrony requires the simultaneous extraction and integration of dynamic information from more than one person. Hence, the representation of synchrony/asynchrony cannot be attributed to augmented or additive processing of individual actors. Our findings therefore provide important new evidence that social interactions recruit dedicated visual processing within the social perception network that extends beyond that engaged by the faces and bodies of the constituent individuals.

The Neurological Characteristics of Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a multifaceted neurodevelopmental condition that predominantly affects males and manifests through diverse behavioral impairments, such as difficulties in social engagement and a tendency towards limited, recurrent behaviors. Concepts like the theory of mind and the executive function theory notably emphasize the underlying aspects of the condition, highlighting deficits in understanding others' mental states and domain-general cognitive difficulties, respectively, though receiving varying levels of empirical support. A focus on neurological perspectives, utilizing tools like functional magnetic resonance imaging (fMRI) and electroencephalogram (EEG), is indispensable for unveiling intricate patterns and alterations in brain regions crucial for social cognition and empathy, such as the superior temporal sulcus (STS) and amygdala (AMY). These neurological insights are pivotal in painting a holistic picture of ASD, emphasizing not just the behavioral manifestations but also the underlying neurological substrates. Such an integrated approach is crucial for advancing the current understanding, refining diagnostic methodologies, and developing more targeted interventions, which are vital for addressing the diverse needs and challenges faced by individuals with ASD.

Moving and Static Faces, Bodies, Objects, and Scenes Are Differentially Represented across the Three Visual Pathways.

Models of human cortex propose the existence of neuroanatomical pathways specialized for different behavioral functions. These pathways include a ventral pathway for object recognition, a dorsal pathway for performing visually guided physical actions, and a recently proposed third pathway for social perception. In the current study, we tested the hypothesis that different categories of moving stimuli are differentially processed across the dorsal and third pathways according to their behavioral implications. Human participants (n = 30) were scanned with fMRI while viewing moving and static stimuli from four categories (faces, bodies, scenes, and objects). A whole-brain group analysis showed that moving bodies and moving objects increased neural responses in the bilateral posterior parietal cortex, parts of the dorsal pathway. By contrast, moving faces and moving bodies increased neural responses, the superior temporal sulcus, part of the third pathway. This pattern of results was also supported by a separate ROI analysis showing that moving stimuli produced more robust neural responses for all visual object categories, particularly in lateral and dorsal brain areas. Our results suggest that dynamic naturalistic stimuli from different categories are routed in specific visual pathways that process dissociable behavioral functions.

Interpretable prediction of brain activity during conversations from multimodal behavioral signals.

We present an analytical framework aimed at predicting the local brain activity in uncontrolled experimental conditions based on multimodal recordings of participants' behavior, and its application to a corpus of participants having conversations with another human or a conversational humanoid robot. The framework consists in extracting high-level features from the raw behavioral recordings and applying a dynamic prediction of binarized fMRI-recorded local brain activity using these behavioral features. The objective is to identify behavioral features required for this prediction, and their relative weights, depending on the brain area under investigation and the experimental condition. In order to validate our framework, we use a corpus of uncontrolled conversations of participants with a human or a robotic agent, focusing on brain regions involved in speech processing, and more generally in social interactions. The framework not only predicts local brain activity significantly better than random, it also quantifies the weights of behavioral features required for this prediction, depending on the brain area under investigation and on the nature of the conversational partner. In the left Superior Temporal Sulcus, perceived speech is the most important behavioral feature for predicting brain activity, regardless of the agent, while several features, which differ between the human and robot interlocutors, contribute to the prediction in regions involved in social cognition, such as the TemporoParietal Junction. This framework therefore allows us to study how multiple behavioral signals from different modalities are integrated in individual brain regions during complex social interactions.

Cross-frequency coupling in cortico-hippocampal networks supports the maintenance of sequential auditory information in short-term memory.

It has been suggested that cross-frequency coupling in cortico-hippocampal networks enables the maintenance of multiple visuo-spatial items in working memory. However, whether this mechanism acts as a global neural code for memory retention across sensory modalities remains to be demonstrated. Intracranial EEG data were recorded while drug-resistant patients with epilepsy performed a delayed matched-to-sample task with tone sequences. We manipulated task difficulty by varying the memory load and the duration of the silent retention period between the to-be-compared sequences. We show that the strength of theta-gamma phase amplitude coupling in the superior temporal sulcus, the inferior frontal gyrus, the inferior temporal gyrus, and the hippocampus (i) supports the short-term retention of auditory sequences; (ii) decodes correct and incorrect memory trials as revealed by machine learning analysis; and (iii) is positively correlated with individual short-term memory performance. Specifically, we show that successful task performance is associated with consistent phase coupling in these regions across participants, with gamma bursts restricted to specific theta phase ranges corresponding to higher levels of neural excitability. These findings highlight the role of cortico-hippocampal activity in auditory short-term memory and expand our knowledge about the role of cross-frequency coupling as a global biological mechanism for information processing, integration, and memory in the human brain.

Conversational production and comprehension: fMRI-evidence reminiscent of but deviant from the classical Broca-Wernicke model.

A key question in research on the neurobiology of language is to which extent the language production and comprehension systems share neural infrastructure, but this question has not been addressed in the context of conversation. We utilized a public fMRI dataset where 24 participants engaged in unscripted conversations with a confederate outside the scanner, via an audio-video link. We provide evidence indicating that the two systems share neural infrastructure in the left-lateralized perisylvian language network, but diverge regarding the level of activation in regions within the network. Activity in the left inferior frontal gyrus was stronger in production compared to comprehension, while comprehension showed stronger recruitment of the left anterior middle temporal gyrus and superior temporal sulcus, compared to production. Although our results are reminiscent of the classical Broca-Wernicke model, the anterior (rather than posterior) temporal activation is a notable difference from that model. This is one of the findings that may be a consequence of the conversational setting, another being that conversational production activated what we interpret as higher-level socio-pragmatic processes. In conclusion, we present evidence for partial overlap and functional asymmetry of the neural infrastructure of production and comprehension, in the above-mentioned frontal vs temporal regions during conversation.

Preoperative Simulation in Epilepsy Surgery

In patients with intractable epilepsy, seizure focus resection can yield favorable seizure outcomes. First, the localization of the seizure focus is estimated by noninvasive methods such as magnetic resonance imaging(MRI), video-electroencephalography(EEG)monitoring, nuclear medicine examinations, magnetoencephalography, and neuropsychological tests. A subgroup of patients may require additional information obtained from the intracranial EEG. There are two major methods for intracranial EEG: intracranial EEG with subdural grid electrodes(SDG)and stereotactic electroencephalography. If the estimated seizure focus overlaps with the eloquent area in noninvasive studies, the margin and extent of the resection are determined by the results of intracranial EEG and functional mapping by electrical cortical stimulation. Herein, we present a case of lobe epilepsy with subtle MRI lesions in the superior temporal sulcus of the language-dominant hemisphere. The results of the SDG and functional mapping showed that the seizure onset zone overlapped with the language area. Resection of the middle and inferior temporal gyri and multiple transections of the language area resulted in Engel IIB seizure outcomes. In such cases, a thorough preoperative simulation is required to determine the best resection margin for seizure control and functional preservation.

A shared neural code for perceiving and remembering social interactions in the human superior temporal sulcus

Recognizing and remembering social information is a crucial cognitive skill. Neural patterns in the superior temporal sulcus (STS) support our ability to perceive others' social interactions. However, despite the prominence of social interactions in memory, the neural basis of remembering social interactions is still unknown. To fill this gap, we investigated the brain mechanisms underlying memory of others' social interactions during free spoken recall of a naturalistic movie. By applying machine learning-based fMRI encoding analyses to densely labeled movie and recall data we found that a subset of the STS activity evoked by viewing social interactions predicted neural responses in not only held-out movie data, but also during memory recall. These results provide the first evidence that activity in the STS is reinstated in response to specific social content and that its reactivation underlies our ability to remember others’ interactions. These findings further suggest that the STS contains representations of social interactions that are not only perceptually driven, but also more abstract or conceptual in nature.

Retinal Microvasculature Causally Affects the Brain Cortical Structure: A Mendelian Randomization Study

PurposeTo reveal the causality between retinal vascular density (VD), fractal dimension (FD) and brain cortex structure using Mendelian randomization (MR). DesignCross-sectional study. ParticipantsGenome-wide association studies of VD and FD involving 54,813 participants from the UK Biobank were used. The brain cortical features, including the cortical thickness (TH) and surficial area (SA), were extracted from 51,665 patients across 60 cohorts. SA and TH were measured globally and in 34 functional regions using magnetic resonance imaging. MethodsBidirectional univariable MR (UVMR) was used to detect the causality between FD, VD and brain cortex structure. Multivariable MR (MVMR) was used to adjust for confounding factors, including body mass index and blood pressure. Main Outcome MeasuresThe global and regional measurements of brain cortical surface area and cortical thickness. ResultsAt the global level, higher VD is related to decreased TH (β =-0.0140 mm, 95% CI: -0.0269 mm to -0.0011 mm, P = 0.0339). At the functional level, retinal FD is related to the TH of banks of the superior temporal sulcus and transverse temporal region without global weighted, as well as the SA of the posterior cingulate after adjustment. VD is correlated with the SA of subregions of the frontal lobe and temporal lobe, in addition to the TH of the inferior temporal, entorhinal and pars opercularis regions in both UVMR and MVMR. Bidirectional MR studies showed a causation between the SA of the parahippocampal and cauda middle frontal gyrus and retinal VD. No pleiotropy was detected. ConclusionsFD and VD causally influence the cortical structure and vice versa, indicating that the retinal microvasculature may serve as a biomarker for cortex structural changes. Our study provides insights into utilizing noninvasive fundus images to predict cortical structural deteriorations and neuropsychiatric disorders.