Posterior Superior Temporal Gyrus Research Articles

Brain and cognitive changes in patients with long COVID compared with infection-recovered control subjects.

Between 2.5 and 28% of people infected with SARS-CoV-2 suffer Long COVID or persistence of symptoms for months after acute illness. Many symptoms are neurological, but the brain changes underlying the neuropsychological impairments remain unclear. This study aimed to provide a detailed description of the cognitive profile, the pattern of brain alterations in Long COVID and the potential association between them. To address these objectives, 83 patients with persistent neurological symptoms after COVID-19 were recruited, and 22 now healthy controls chosen because they had suffered COVID-19 but did not experience persistent neurological symptoms. Patients and controls were matched for age, sex and educational level. All participants were assessed by clinical interview, comprehensive standardized neuropsychological tests and structural MRI. The mean global cognitive function of patients with Long COVID assessed by ACE III screening test (Overall Cognitive level - OCLz= -0.39± 0.12) was significantly below the infection recovered-controls (OCLz= +0.32± 0.16, p< 0.01). We observed that 48% of patients with Long COVID had episodic memory deficit, with 27% also impaired overall cognitive function, especially attention, working memory, processing speed and verbal fluency. The MRI examination included grey matter morphometry and whole brain structural connectivity analysis. Compared to infection recovered controls, patients had thinner cortex in a specific cluster centred on the left posterior superior temporal gyrus. In addition, lower fractional anisotropy (FA) and higher radial diffusivity (RD) were observed in widespread areas of the patients' cerebral white matter relative to these controls. Correlations between cognitive status and brain abnormalities revealed a relationship between altered connectivity of white matter regions and impairments of episodic memory, overall cognitive function, attention and verbal fluency. This study shows that patients with neurological Long COVID suffer brain changes, especially in several white matter areas, and these are associated with impairments of specific cognitive functions.

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.

Sentence superiority in the reading brain

When a sequence of written words is briefly presented and participants are asked to identify just one word at a post-cued location, then word identification accuracy is higher when the word is presented in a grammatically correct sequence compared with an ungrammatical sequence. This sentence superiority effect has been reported in several behavioral studies and two EEG investigations. Taken together, the results of these studies support the hypothesis that the sentence superiority effect is primarily driven by rapid access to a sentence-level representation via partial word identification processes that operate in parallel over several words. Here we used MEG to examine the neural structures involved in this early stage of written sentence processing, and to further specify the timing of the different processes involved. Source activities over time showed grammatical vs. ungrammatical differences first in the left inferior frontal gyrus (IFG: 321-406 ms), then the left anterior temporal lobe (ATL: 466-531 ms), and finally in both left IFG (549-602 ms) and left posterior superior temporal gyrus (pSTG: 553-622 ms). We interpret the early IFG activity as reflecting the rapid bottom-up activation of sentence-level representations, including syntax, enabled by partly parallel word processing. Subsequent activity in ATL and pSTG is thought to reflect the constraints imposed by such sentence-level representations on on-going word-based semantic activation (ATL), and the subsequent development of a more detailed sentence-level representation (pSTG). These results provide further support for a cascaded interactive-activation account of sentence reading.

Perceiving and misperceiving speech: lexical and sublexical processing in the superior temporal lobes.

Listeners can use prior knowledge to predict the content of noisy speech signals, enhancing perception. However, this process can also elicit misperceptions. For the first time, we employed a prime-probe paradigm and transcranial magnetic stimulation to investigate causal roles for the left and right posterior superior temporal gyri (pSTG) in the perception and misperception of degraded speech. Listeners were presented with spectrotemporally degraded probe sentences preceded by a clear prime. To produce misperceptions, we created partially mismatched pseudo-sentence probes via homophonic nonword transformations (e.g. The little girl was excited to lose her first tooth-Tha fittle girmn wam expited du roos har derst cooth). Compared to a control site (vertex), inhibitory stimulation of the left pSTG selectively disrupted priming of real but not pseudo-sentences. Conversely, inhibitory stimulation of the right pSTG enhanced priming of misperceptions with pseudo-sentences, but did not influence perception of real sentences. These results indicate qualitatively different causal roles for the left and right pSTG in perceiving degraded speech, supporting bilateral models that propose engagement of the right pSTG in sublexical processing.

Intracranial electrophysiology of spectrally degraded speech in the human cortex.

Cochlear implants (CIs) are the treatment of choice for severe to profound hearing loss. Variability in CI outcomes remains despite advances in technology and is attributed in part to differences in cortical processing. Studying these differences in CI users is technically challenging. Spectrally degraded stimuli presented to normal-hearing individuals approximate input to the central auditory system in CI users. This study used intracranial electroencephalography (iEEG) to investigate cortical processing of spectrally degraded speech. Participants were adult neurosurgical epilepsy patients. Stimuli were utterances /aba/ and /ada/, spectrally degraded using a noise vocoder (1-4 bands) or presented without vocoding. The stimuli were presented in a two-alternative forced choice task. Cortical activity was recorded using depth and subdural iEEG electrodes. Electrode coverage included auditory core in posteromedial Heschl's gyrus (HGPM), superior temporal gyrus (STG), ventral and dorsal auditory-related areas, and prefrontal and sensorimotor cortex. Analysis focused on high gamma (70-150 Hz) power augmentation and alpha (8-14 Hz) suppression. Chance task performance occurred with 1-2 spectral bands and was near-ceiling for clear stimuli. Performance was variable with 3-4 bands, permitting identification of good and poor performers. There was no relationship between task performance and participants demographic, audiometric, neuropsychological, or clinical profiles. Several response patterns were identified based on magnitude and differences between stimulus conditions. HGPM responded strongly to all stimuli. A preference for clear speech emerged within non-core auditory cortex. Good performers typically had strong responses to all stimuli along the dorsal stream, including posterior STG, supramarginal, and precentral gyrus; a minority of sites in STG and supramarginal gyrus had a preference for vocoded stimuli. In poor performers, responses were typically restricted to clear speech. Alpha suppression was more pronounced in good performers. In contrast, poor performers exhibited a greater involvement of posterior middle temporal gyrus when listening to clear speech. Responses to noise-vocoded speech provide insights into potential factors underlying CI outcome variability. The results emphasize differences in the balance of neural processing along the dorsal and ventral stream between good and poor performers, identify specific cortical regions that may have diagnostic and prognostic utility, and suggest potential targets for neuromodulation-based CI rehabilitation strategies.

Single‐nuclei transcriptomic identifies type‐specific neuronal cell vulnerability and non‐neuronal molecular changes in Amnestic and Logopenic Variant Primary Progressive Aphasia Alzheimer’s disease

AbstractBackgroundIndividuals with neuropathological criteria for Alzheimer’s disease (AD) may manifest with atypical clinical syndromes. Past work showed that the neurobiological basis for these differences is related to specific neuronal vulnerabilities for tau pathology. For instance, amnestic cases have a higher burden of neurofibrillary changes in CA1. In contrast, logopenic variant primary progressive aphasia (lvPPA) cases have a higher tau burden in the superior temporal gyrus (STG). Single‐cell technology enables investigations on the molecular basis of differential neuronal vulnerability in AD. Therefore, we investigated factors underlying selective vulnerability using brain samples from individuals with pure AD with different clinical manifestations.MethodsnRNA Sequencing using the Chromium Single Cell 3′ (10X Genomics, USA) on nuclei cells extracted from the CA1 sector and posterior STG of postmortem brain tissue of 24 individuals either meeting pathological criteria for AD (A3B3C3; 12 amnestic and eight lvPPA) and healthy controls (A≤1B≤1C≤1; n = 4) (Table 1, Fig. 1A/B). Bioinformatics analyses were conducted using Cell Ranger and R software. Comparisons between cell subpopulations were conducted with Wald statistical test, and p‐values &lt; .05 were considered significant.ResultAfter quality control, we recovered 98,180 nuclei with a mean of 2,130 genes per nuclei. Upon cross‐sample alignment and t‐stochastic neighborhood embedding clustering (Fig. 1C), we found 21 excitatory neuronal subpopulations (Exc‐sub) in CA1 and 26 in STG, and 22 and 27 inhibitory neuronal subpopulations (Inh‐sub) in CA1 and STG, respectively; 16 astrocytes subpopulations in both areas and 20 microglia subpopulations in CA1 and 17 in STG (Fig. 2). One STG Exc‐sub, expressing CUX2 and LAMP5 genes showed vulnerability in lvPPA patients. Also, one STG Inh‐sub, expressing the ADARB2 gene, showed vulnerability for all AD patients. Furthermore, two astrocytes subpopulations (one in both areas and one in STG) and three STG microglia subpopulations showed proportional composition changes comparing AD patients and HC.ConclusionOur preliminary study identified a vulnerable population of excitatory neurons related to lvPPA. We are conducting validation studies using quantitative pathology to confirm these results. Furthermore, analysis of a higher number of cases is ongoing and will continue to inform on factors associated with neuronal vulnerability.

Causal evidence for a coordinated temporal interplay within the language network.

Recent neurobiological models on language suggest that auditory sentence comprehension is supported by a coordinated temporal interplay within a left-dominant brain network, including the posterior inferior frontal gyrus (pIFG), posterior superior temporal gyrus and sulcus (pSTG/STS), and angular gyrus (AG). Here, we probed the timing and causal relevance of the interplay between these regions by means of concurrent transcranial magnetic stimulation and electroencephalography (TMS-EEG). Our TMS-EEG experiments reveal region- and time-specific causal evidence for a bidirectional information flow from left pSTG/STS to left pIFG and back during auditory sentence processing. Adapting a condition-and-perturb approach, our findings further suggest that the left pSTG/STS can be supported by the left AG in a state-dependent manner.

The differential processing of verbal jokes by neural substrates in indigenous and Han Chinese populations: An fMRI study

Limited research has been conducted on humor among the Taiwanese indigenous (IND) population. This study attempted to identify the differential neural correlates of humor comprehension and appreciation between IND and Han Chinese (HAN) populations. Each participant was presented with jokes and non-jokes. IND participants when encountered with jokes displayed a greater activation of the mesolimbic dopaminergic reward system, including the amygdala, midbrain, and nucleus accumbens than HAN participants. This suggests a more pleasurable response and appreciation of humor. The IND group also displayed greater activation in the right temporoparietal junction (rTPJ) than HAN, suggesting that the IND group may experience a greater sense of novelty and be more involved in social understanding, thus exhibiting greater humor appreciation. In terms of humor comprehension, both IND and HAN showed greater activation in the superior temporal gyrus (STG) and dorsal anterior cingulate cortex (dACC). IND exhibited greater activation in the anterior STG (aSTG), while HAN showed greater activation in the posterior STG (pSTG). This suggests that the IND tends to integrate emotional messages, whereas the HAN focuses on comprehending semantic cognitive information. Interestingly, HAN did not show any greater activation than IND in terms of appreciation of humor. These group disparities have substantial implications for advancing our knowledge of the neural mechanisms underlying humor comprehension and appreciation.

Right, but not left, posterior superior temporal gyrus is causally involved in vocal feedback control

The posterior superior temporal gyrus (pSTG) has been implicated in the integration auditory feedback and motor system for controlling vocal production. However, the question as to whether and how the pSTG is causally involved in vocal feedback control is currently unclear. To this end, the present study selectively stimulated the left or right pSTG with continuous theta burst stimulation (c-TBS) in healthy participants, then used event-related potentials to investigate neurobehavioral changes in response to altered auditory feedback during vocal pitch regulation. The results showed that, compared to control (vertex) stimulation, c-TBS over the right pSTG led to smaller vocal compensations for pitch perturbations accompanied by smaller cortical N1 and larger P2 responses. Enhanced P2 responses received contributions from the right-lateralized temporal and parietal regions as well as the insula, and were significantly correlated with suppressed vocal compensations. Surprisingly, these effects were not found when comparing c-TBS over the left pSTG with control stimulation. Our findings provide evidence that supports a causal relationship between right, but not left, pSTG and auditory-motor integration for vocal pitch production. This lends support to a right-lateralized contribution of the pSTG in not only detecting vocal feedback errors but also driving motor commands for error correction.

The neural basis of Number and Person phi-features processing: An fMRI study in highly proficient bilinguals

Abstract No studies have investigated the neural correlates of Number and Person agreement processing in bilinguals. Because a previous fMRI study showed difference in L1 and L2 morphosyntactic processing of L1 Turkish–L2 Persian bilinguals, it was of interest whether this difference can be specifically attributed to Number or Person processing. Therefore, we reanalyzed these data at the whole-brain level, revealing a selective response for Number Violations in the pars opercularis (PO), whereas Number and Person Violations activated the posterior superior temporal gyrus (pSTG). These results support the decomposition of agreement projections and their neuroanatomical substrates in bilinguals and confirm the involvement of systematically different feature-checking and feature-mapping mechanisms in Number and Person agreement but shared mechanisms between L1 and L2. Moreover, at variance with previous reports, Number Violations evoked more effects than Person Violations in pSTG, suggesting qualitatively different processing underlying R-expression and pronominal controllers.

Right, but not left, posterior superior temporal gyrus is causally involved in vocal feedback control

The posterior superior temporal gyrus (pSTG) has been implicated in the integration of auditory feedback and motor system for controlling vocal production. However, the question as to whether and how the pSTG is causally involved in vocal feedback control is currently unclear. To this end, the present study selectively stimulated the left or right pSTG with continuous theta burst stimulation (c-TBS) in healthy participants, then used event-related potentials to investigate neurobehavioral changes in response to altered auditory feedback during vocal pitch regulation. The results showed that, compared to control (vertex) stimulation, c-TBS over the right pSTG led to smaller vocal compensations for pitch perturbations accompanied by smaller cortical N1 and larger P2 responses. Enhanced P2 responses received contributions from the right-lateralized temporal and parietal regions as well as the insula, and were significantly correlated with suppressed vocal compensations. Surprisingly, these effects were not found when comparing c-TBS over the left pSTG with control stimulation. Our findings provide evidence, for the first time, that supports a causal relationship between right, but not left, pSTG and auditory-motor integration for vocal pitch regulation. This lends support to a right-lateralized contribution of the pSTG in not only the bottom-up detection of vocal feedback errors but also the involvement of driving motor commands for error correction in a top-down manner.

Dynamic network properties of the superior temporal gyrus mediate the impact of brain age gap on chronic aphasia severity

Brain structure deteriorates with aging and predisposes an individual to more severe language impairments (aphasia) after a stroke. However, the underlying mechanisms of this relation are not well understood. Here we use an approach to model brain network properties outside the stroke lesion, network controllability, to investigate relations among individualized structural brain connections, brain age, and aphasia severity in 93 participants with chronic post-stroke aphasia. Controlling for the stroke lesion size, we observe that lower average controllability of the posterior superior temporal gyrus (STG) mediates the relation between advanced brain aging and aphasia severity. Lower controllability of the left posterior STG signifies that activity in the left posterior STG is less likely to yield a response in other brain regions due to the topological properties of the structural brain networks. These results indicate that advanced brain aging among individuals with post-stroke aphasia is associated with disruption of dynamic properties of a critical language-related area, the STG, which contributes to worse aphasic symptoms. Because brain aging is variable among individuals with aphasia, our results provide further insight into the mechanisms underlying the variance in clinical trajectories in post-stroke aphasia.

Functional connectivity explains how neuronavigated TMS of posterior temporal subregions differentially affect language processing

Background“Wernicke's area” is most often used to describe the posterior superior temporal gyrus (STG) and refers to a region traditionally thought to support language comprehension. However, the posterior STG additionally plays a critical role in language production. The purpose of the current study was to determine to what extent regions within the posterior STG are selectively recruited during language production. Methods23 healthy right-handed participants completed an auditory fMRI localizer task, resting-state fMRI and underwent neuronavigated TMS language mapping. We applied repetitive TMS bursts during a picture naming paradigm to probe speech disruptions of different categories (anomia, speech arrest, semantic paraphasia and phonological paraphasia). We combined an in-house built high precision stimulation software suite with E-field modeling to map the naming errors to cortical regions and revealed a dissociation of language functions within the temporal gyrus. Resting state fMRI was used to explain how E-field peaks of different categories differentially affected language production. ResultsPeaks for phonological and semantic errors were found in the STG while those for anomia and speech arrest were located in the MTG. Seed-based connectivity analysis revealed a local connectivity pattern for phonological and semantic errors, while anomia and speech arrest seeds resulted in a larger network between IFG and posterior MTG. ConclusionsOur study provides important insights into the functional neuroanatomy of language production and might help to increase the current understanding of specific language production difficulties on a causal level.

Intraoperative cortical localization of music and language reveals signatures of structural complexity in posterior temporal cortex

Language and music involve the productive combination of basic units into structures. It remains unclear whether brain regions sensitive to linguistic and musical structure are co-localized. We report an intraoperative awake craniotomy in which a left-hemispheric language-dominant professional musician underwent cortical stimulation mapping (CSM) and electrocorticography of music and language perception and production during repetition tasks. Musical sequences were melodic or amelodic, and differed in algorithmic compressibility (Lempel-Ziv complexity). Auditory recordings of sentences differed in syntactic complexity (single vs. multiple phrasal embeddings). CSM of posterior superior temporal gyrus (pSTG) disrupted music perception and production, along with speech production. pSTG and posterior middle temporal gyrus (pMTG) activated for language and music (broadband gamma; 70-150Hz). pMTG activity was modulated by musical complexity, while pSTG activity was modulated by syntactic complexity. This points to shared resources for music and language comprehension, but distinct neural signatures for the processing of domain-specific structural features.

Association of Arterial Stiffness Index and Brain Structure in the UK Biobank: A 10-Year Retrospective Analysis.

Arterial stiffening and changes in brain structure both occur with normal aging and can be exacerbated via acquired health conditions. While cross-sectional associations exist, the longitudinal relationship between arterial stiffness and brain structure remains unclear. In this study, we investigated 1) associations between baseline arterial stiffness index (ASI) and brain structure (global and regional grey matter volumes (GMV), white matter hyperintensities (WMH)) 10-years post-baseline (10.4±0.8 years) and 2) associations between the 10-year change in ASI from baseline and brain structure 10-years post-baseline in 650 healthy middle- to older-aged adults (53.4±7.5 years) from the UK Biobank. We observed significant associations between baseline ASI and GMV (p<0.001) and WMH (p=0.0036) 10-years post-baseline. No significant associations between 10-year change in ASI and brain structure (global GMV p=0.24; WMH volume p=0.87) were observed. There were significant associations of baseline ASI in 2 of 60 regional brain volumes analyzed (right posterior superior temporal gyrus p=0.001; left superior lateral occipital cortex p<0.001). Strong associations with baseline ASI, but not changes in ASI over 10-years, suggest arterial stiffness at the entry point of older adulthood is more impactful on brain structure 10-years later compared to age-related stiffening. Based on these associations, we suggest clinical monitoring and potential intervention for reducing arterial stiffness should occur in midlife to reduce vascular contributions to structural changes in the brain, supporting a healthy trajectory of brain aging. Our findings also support use of ASI as a surrogate for gold standard measures in showing overall relationships between arterial stiffness and brain structure.

Unexpected sound omissions are signaled in human posterior superior temporal gyrus: an intracranial study.

Context modulates sensory neural activations enhancing perceptual and behavioral performance and reducing prediction errors. However, the mechanism of when and where these high-level expectations act on sensory processing is unclear. Here, we isolate the effect of expectation absent of any auditory evoked activity by assessing the response to omitted expected sounds. Electrocorticographic signals were recorded directly from subdural electrode grids placed over the superior temporal gyrus (STG). Subjects listened to a predictable sequence of syllables, with some infrequently omitted. We found high-frequency band activity (HFA, 70-170Hz) in response to omissions, which overlapped with a posterior subset of auditory-active electrodes in STG. Heard syllables could be distinguishable reliably from STG, but not the identity of the omitted stimulus. Both omission- and target-detection responses were also observed in the prefrontal cortex. We propose that the posterior STG is central for implementing predictions in the auditory environment. HFA omission responses in this region appear to index mismatch-signaling or salience detection processes.

Neurodevelopmental trajectories of letter and speech sound processing from preschool to the end of elementary school

Learning to read alphabetic languages starts with learning letter–speech-sound associations. How this process changes brain function during development is still largely unknown. We followed 102 children with varying reading skills in a mixed-longitudinal/cross-sectional design from the prereading stage to the end of elementary school over five time points (n = 46 with two and more time points, of which n = 16 fully-longitudinal) to investigate the neural trajectories of letter and speech sound processing using fMRI. Children were presented with letters and speech sounds visually, auditorily, and audiovisually in kindergarten (6.7yo), at the middle (7.3yo) and end of first grade (7.6yo), and in second (8.4yo) and fifth grades (11.5yo). Activation of the ventral occipitotemporal cortex for visual and audiovisual processing followed a complex trajectory, with two peaks in first and fifth grades. The superior temporal gyrus (STG) showed an inverted U-shaped trajectory for audiovisual letter processing, a development that in poor readers was attenuated in middle STG and absent in posterior STG. Finally, the trajectories for letter-speech-sound integration were modulated by reading skills and showed differing directionality in the congruency effect depending on the time point. This unprecedented study captures the development of letter processing across elementary school and its neural trajectories in children with varying reading skills.

Validity of chronometric TMS for probing the time-course of word production: a modified replication.

In the present study, we used chronometric TMS to probe the time-course of 3 brain regions during a picture naming task. The left inferior frontal gyrus, left posterior middle temporal gyrus, and left posterior superior temporal gyrus were all separately stimulated in 1 of 5 time-windows (225, 300, 375, 450, and 525ms) from picture onset. We found posterior temporal areas to be causally involved in picture naming in earlier time-windows, whereas all 3 regions appear to be involved in the later time-windows. However, chronometric TMS produces nonspecific effects that may impact behavior, and furthermore, the time-course of any given process is a product of both the involved processing stages along with individual variation in the duration of each stage. We therefore extend previous work in the field by accounting for both individual variations in naming latencies and directly testing for nonspecific effects of TMS. Our findings reveal that both factors influence behavioral outcomes at the group level, underlining the importance of accounting for individual variations in naming latencies, especially for late processing stages closer to articulation, and recognizing the presence of nonspecific effects of TMS. The paper advances key considerations and avenues for future work using chronometric TMS to study overt production.

Altered Functional Connectivity Strength in Distinct Brain Networks of Children With Early-Onset Schizophrenia.

Schizophrenia is regarded as a brain network or connectome disorder that is associated with neurodevelopment. Children with early-onset schizophrenia (EOS) provide an opportunity to evaluate the neuropathology of schizophrenia at a very early stage without potential confounding factors. But dysfunction in brain networks of schizophrenia is inconsistent. To identify abnormal functional connectivity (FC) in EOS patients and relationships with clinical symptoms, we aimed to reveal neuroimaging phenotypes of EOS. Prospective, cross-sectional. Twenty-six female/22 male patients (age:14.3 ± 3.45 years) with first-episode EOS, 27 female/22 male age- and gender-matched healthy controls (HC) (age:14.1 ± 4.32). 3-T, resting-state (rs) gradient-echo echo-planar imaging and three-dimensional magnetization-prepared rapid gradient-echo imaging. Intelligence quotient (IQ) was measured by the Wechsler Intelligence Scale-Fourth edition for Children (WISC-IV). The clinical symptoms were evaluated by the Positive and Negative Syndrome Scale (PANSS). FC strength (FCS) from rs functional MRI (rsfMRI) was used to investigate functional integrity of global brain regions. In addition, associations between regionally altered FCS and clinical symptoms in EOS patients were examined. Two-sample t-test controlling for sample size, diagnostic method, brain volume algorithm, and age of the subjects, Bonferroni correction, Pearson's correlation analysis. A P-value <0.05 with a minimum cluster size of 50 voxels was considered statistically significant. Compared with HC, EOS patients had significantly lower total IQ scores (IQ:91.5 ± 16.1), increased FCS in the bilateral precuneus, left dorsolateral prefrontal cortex, left thalamus, and left parahippocampus (paraHIP), and decreased FCS in the right cerebellum posterior lobe and right superior temporal gyrus. The PANSS total score of EOS patients (PANSS total score:74.30 ± 7.23) was found to be positively correlated to FCS in the left paraHIP (r=0.45). Our study revealed that disrupted FC of brain hubs illustrate multiple abnormalities in brain networks in EOS patients. 1 TECHNICAL EFFICACY STAGE: 2.

Dynamic causal modeling analysis reveals the modulation of motor cortex and integration in superior temporal gyrus during multisensory speech perception

AbstractThe processing of speech information from various sensory modalities is crucial for human communication. Both left posterior superior temporal gyrus (pSTG) and motor cortex importantly involve in the multisensory speech perception. However, the dynamic integration of primary sensory regions to pSTG and the motor cortex remain unclear. Here, we implemented a behavioral experiment of classical McGurk effect paradigm and acquired the task functional magnetic resonance imaging (fMRI) data during synchronized audiovisual syllabic perception from 63 normal adults. We conducted dynamic causal modeling (DCM) analysis to explore the cross-modal interactions among the left pSTG, left precentral gyrus (PrG), left middle superior temporal gyrus (mSTG), and left fusiform gyrus (FuG). Bayesian model selection favored a winning model that included modulations of connections to PrG (mSTG → PrG, FuG → PrG), from PrG (PrG → mSTG, PrG → FuG), and to pSTG (mSTG → pSTG, FuG → pSTG). Moreover, the coupling strength of the above connections correlated with behavioral McGurk susceptibility. In addition, significant differences were found in the coupling strength of these connections between strong and weak McGurk perceivers. Strong perceivers modulated less inhibitory visual influence, allowed less excitatory auditory information flowing into PrG, but integrated more audiovisual information in pSTG. Taken together, our findings show that the PrG and pSTG interact dynamically with primary cortices during audiovisual speech, and support the motor cortex plays a specifically functional role in modulating the gain and salience between auditory and visual modalities.