Targeting the superior temporal gyrus with real-time fMRI neurofeedback: A pilot study of the indirect effects on self-referential processes in schizophrenia.

BACKGROUND: Individuals with schizophrenia (SZ) and auditory hallucinations (AHs) display a distorted sense of self and self-other boundaries. Alterations of activity in midline cortical structures such as the prefrontal cortex (mPFC) and anterior cingulate cortex (ACC) during self-reference as well as in the superior temporal gyrus (STG) have been proposed as neuromarkers of SZ and AHs. METHODS: In this randomized, participant-blinded, sham-controlled trial, 22 adults (18 males) with SZ spectrum disorders (SZ or schizoaffective disorder) and frequent medication-resistant AHs received one session of real-time fMRI neurofeedback (NFB) either from the STG (n = 11; experimental group) or motor cortex (n = 11; control group). During NFB, participants were instructed to upregulate their STG activity by attending to pre-recorded sentences spoken in their own voice and downregulate it by ignoring unfamiliar voices. Before and after NFB, participants completed a self-reference task where they evaluated if trait adjectives referred to themselves (self condition), Abraham Lincoln (other condition), or whether adjectives had a positive valence (semantic condition). FMRI activation analyses of self-reference task data tested between-group changes after NFB (self>semantic, post>pre-NFB, experimental>control). Analyses were pre-masked within a self-reference network. RESULTS: Activation analyses revealed significantly (p < 0.001) greater activation increase in the experimental, compared to the control group, after NFB within anterior regions of the self-reference network (mPFC, ACC, superior frontal cortex). CONCLUSIONS: STG-NFB was associated with activity increase in the mPFC, ACC, and superior frontal cortex during self-reference. Modulating the STG is associated with activation changes in other, not-directly targeted, regions subserving higher-level cognitive processes associated with self-referential processes and AHs psychopathology in SZ. CLINICALTRIALS: GOV: Rt-fMRI Neurofeedback and AH in Schizophrenia; https://clinicaltrials.gov/study/NCT03504579.

Surface electromyography analysis of ankle flexor and extensor activity under different standing stability levels.

Background: To observe the activation strategies of the ankle muscles using surface electromyography (sEMG) during single-leg standing (SLS) and both-leg standing (BLS) on flat ground (FG), soft mat (SM), and BOSU ball (BB) surfaces. Methods: Thirty healthy young adults participated in the study. The muscle activities of the tibialis anterior (TA) and gastrocnemius medial (GM) were measured on the three surfaces during SLS and BLS. Electromyographic evaluations of the TA and GM were recorded during maximum voluntary isometric contractions (MVIC). Muscle activation was evaluated using MVIC%, and muscle co-contraction was evaluated using the co-contraction index (CI). Results: A statistically significant increase was observed in the MVIC% of the TA, GM, and CI on the three surfaces during SLS compared to BLS, except for the comparison of CI on BB between SLS and BLS (t = -1.35, p = 0.19). The MVIC% of the TA and GM during SLS and BLS on BB was significantly increased in comparison with FG and SM. The CI during BLS on BB increased compared to FG (t = 3.19, p < 0.01) and SM (t = 4.64, p < 0.01). The CI during BLS on SM (t = -1.46, p = 0.15) decreased when compared to FG but without statistical significance. Conclusions: SLS and unstable surfaces can induce greater muscle activation, and SLS can have a greater influence on ankle muscles.

Organization of corticocortical and thalamocortical top-down inputs in the primary visual cortex.

Unified visual perception requires integration of bottom-up and top-down inputs in the primary visual cortex (V1), yet the organization of top-down inputs in V1 remains unclear. Here, we used optogenetics-assisted circuit mapping to identify how multiple top-down inputs from higher-order cortical and thalamic areas engage V1 excitatory and inhibitory neurons. Top-down inputs overlap in superficial layers yet segregate in deep layers. Inputs from the medial secondary visual cortex (V2M) and anterior cingulate cortex (ACA) converge on L6 Pyrs, whereas ventrolateral orbitofrontal cortex (ORBvl) and lateral posterior thalamic nucleus (LP) inputs are processed in parallel in Pyr-type-specific subnetworks (Pyr←ORBvl and Pyr←LP) and drive mutual inhibition between them via local interneurons. Our study deepens understanding of the top-down modulation mechanisms of visual processing and establishes that V2M and ACA inputs in L6 employ integrated processing distinct from the parallel processing of LP and ORBvl inputs in L5.

Highly Potent Transparent Passive Cooling Coating via Microphase-Separated Hydrogel Combining Radiative and Evaporative Cooling.

Transparent passive cooling materials can cool targets environmentally without interfering with light transmission or visual information reception. They play a prominent role in solar cells and flexible display cooling. However, achieving potent transparent cooling remains challenging, because light transmission is accompanied by thermal energy. Here we propose to realize effective passive cooling in transparent materials via a microscale phase separation hydrogel film. The poly(N-isopropylacrylamide-co-acrylamide) hydrogel presents light transmittance of >96% and infrared emissivity as high as 95%. The microphase-separated structure affords a higher enthalpy of evaporation. The film is highly adhesive. In field applications, it reduces temperatures by 9.14 °C compared to those with uncovered photovoltaic panels and 7.68 °C compared to those for bare flexible light-emitting diode screens. Simulations indicate that energy savings of 32.76-51.65 MJ m-2 year-1 can be achieved in typical tropical monsoon climates and temperate continental climates. We expect this work to contribute to energy-efficient materials and a carbon-neutral society.

Seven Tesla Evidence for Columnar and Rostral-Caudal Organization of the Human Periaqueductal Gray Response in the Absence of Threat: A Working Memory Study.

The periaqueductal gray (PAG) is a small midbrain structure that surrounds the cerebral aqueduct, regulates brain-body communication, and is often studied for its role in "fight-or-flight" and "freezing" responses to threat. We used ultra-high-field 7 T fMRI to resolve the PAG in humans and distinguish it from the cerebral aqueduct, examining its in vivo function during a working memory task (N = 87). Both mild and moderate cognitive demands elicited spatially similar patterns of whole-brain blood oxygenation level-dependent (BOLD) response, and moderate cognitive demand elicited widespread BOLD increases above baseline in the brainstem. Notably, these brainstem increases were not significantly greater than those in the mild demand condition, suggesting that a subthreshold brainstem BOLD increase occurred for mild cognitive demand as well. Subject-specific masks were group aligned to examine PAG response. In PAG, both mild and moderate demands elicited a well-defined response in ventrolateral PAG, a region thought to be functionally related to anticipated painful threat in humans and nonhuman animals-yet, the present task posed only the most minimal (if any) "threat," with the cognitive tasks used being approximately as challenging as remembering a phone number. These findings suggest that the PAG may play a more general role in visceromotor regulation, even in the absence of threat.

Study on tank damage and response of adjacent tanks in full time domain of detonation.

The flammable gas volatilized from the storage medium in the tank will burn and explode under the action of an accidental ignition source. Tank explosions formed by the explosive shock wave, explosive debris will not only cause their own damage, but also on the safe operation of adjacent tanks to form a threat. Therefore, in this paper, the vertical dome roof tank is taken as the research object, the criteria of brittle fracture failure of tank materials are constructed, and the multi-field coupling calculation model of tank detonation based on TNT equivalent method is established, taking into account the fluid properties inside and outside the tank, the structure of implosion tank and adjacent tank. By analyzing the full time domain process of gas detonation in tanks under different influence factors, the response to implosion damage of tanks and adjacent tanks under the action of explosion shock wave overpressure and debris was obtained. With the increase of the liquid level, the overpressure and deformation of the shock wave of the detonation tank and adjacent tank decrease, and the type and number of fragments decrease. With the increase of the volume of the tank, the overpressure and stress of the shock wave become larger, the strain rate of the tank becomes larger, and brittle failure is more likely to occur. The types and number of fragments formed increase, but detonation fragments are not formed when the tank is full. The research results in this paper provide a theoretical basis and calculation method for preventing and controlling tank implosion accidents, as well as tank design and tank spacing layout.

Photothermal-promoted O2/OH generation of gold nanotetrapod @ platinum nano-islands for enhanced catalytic/photodynamic therapy.

Ultrasmall platinum (Pt) nanozymes are used for catalytic therapy and oxygen (O2)-dependent photodynamic therapy (PDT) by harnessing the dual-enzyme activities of catalase (CAT) and peroxidase (POD). However, their applications as nanocatalysts are limited due to their low catalytic activity. Herein, we constructed a photothermal-promoted bimetallic nanoplatform (AuNTP@Pt-IR808) by depositing ultrasmall Pt nano-islands and modifying 1-(5-Carboxypentyl)-2-(2-(3-(2-(1-(5-carboxypentyl)-3,3-dimethylindolin-2-ylidene)ethylidene)-2-chlorocyclohex-1-en-1-yl)vinyl)-3,3-dimethyl-3H-indol-1-ium bromide (IR808) on gold nanotetrapod (AuNTP) with CAT/POD activities to enhance PDT/catalytic therapy. In the tumor microenvironment, the ultrasmall Pt can catalyze endogenous hydrogen peroxide (H2O2) to produce O2, relieving tumor hypoxia and enhancing the PDT performance. Moreover, AuNTP integration into the bimetallic nanoplatform showed good electron transfer properties and promoted the POD activity of ultrasmall Pt. Importantly, AuNTP@Pt-IR808 possessed higher photothermal conversion performance than single AuNTPs, which enhanced photothermal therapy (PTT). It also accelerated the CAT/POD dual-enzyme activities, and promoted the generation of singlet oxygen (1O2) and hydroxyl radical (OH). By enhancing the performances of PTT/PDT/catalytic therapy, the developed AuNTP@Pt-IR808 nanoplatform demonstrated good antitumor efficacy against breast cancer.

Fully integrated on-chip FBG interrogator for high-accuracy measurement of wavelengths.

We present the design and fabrication of an on-chip FBG interrogator based on arrayed waveguide grating (AWG) technology. The spectral overlap between adjacent channels in the integrated AWG is significantly enhanced through a combination approach involving the reduction of the output waveguide spacing and an increase in the input waveguide width. As a result of these design choices, our AWG demonstrates excellent spectral consistency, with spectral cross talk exceeding 30 dB. The interrogator seamlessly combining optical and circuitry components achieves full integration and enables a wide range of interrogation wavelengths, including C-band and L-band. With an interrogation range extending up to 80 nm, it theoretically has the capacity to simultaneously interrogate the wavelengths of 20 FBG sensors. Experimental findings demonstrate an absolute interrogation accuracy of less than 2 pm for the fully integrated interrogator. With its compact size, cost-effectiveness, exceptional precision, and ease of integration, the proposed interrogator holds a substantial promise for widespread application in the realm of FBG sensing.

Mindfulness-based real-time fMRI neurofeedback: a randomized controlled trial to optimize dosing for depressed adolescents.

BACKGROUND: Adolescence is characterized by a heightened vulnerability for Major Depressive Disorder (MDD) onset, and currently, treatments are only effective for roughly half of adolescents with MDD. Accordingly, novel interventions are urgently needed. This study aims to establish mindfulness-based real-time fMRI neurofeedback (mbNF) as a non-invasive approach to downregulate the default mode network (DMN) in order to decrease ruminatory processes and depressive symptoms. METHODS: Adolescents (N = 90) with a current diagnosis of MDD ages 13-18-years-old will be randomized in a parallel group, two-arm, superiority trial to receive either 15 or 30 min of mbNF with a 1:1 allocation ratio. Real-time neurofeedback based on activation of the frontoparietal network (FPN) relative to the DMN will be displayed to participants via the movement of a ball on a computer screen while participants practice mindfulness in the scanner. We hypothesize that within-DMN (medial prefrontal cortex [mPFC] with posterior cingulate cortex [PCC]) functional connectivity will be reduced following mbNF (Aim 1: Target Engagement). Additionally, we hypothesize that participants in the 30-min mbNF condition will show greater reductions in within-DMN functional connectivity (Aim 2: Dosing Impact on Target Engagement). Aim 1 will analyze data from all participants as a single-group, and Aim 2 will leverage the randomized assignment to analyze data as a parallel-group trial. Secondary analyses will probe changes in depressive symptoms and rumination. DISCUSSION: Results of this study will determine whether mbNF reduces functional connectivity within the DMN among adolescents with MDD, and critically, will identify the optimal dosing with respect to DMN modulation as well as reduction in depressive symptoms and rumination. TRIAL REGISTRATION: This study has been registered with clinicaltrials.gov, most recently updated on July 6, 2023 (trial identifier: NCT05617495).

Insights into the missing apiosylation step in flavonoid apiosides biosynthesis of Leguminosae plants.

Apiose is a natural pentose containing an unusual branched-chain structure. Apiosides are bioactive natural products widely present in the plant kingdom. However, little is known on the key apiosylation reaction in the biosynthetic pathways of apiosides. In this work, we discover an apiosyltransferase GuApiGT from Glycyrrhiza uralensis. GuApiGT could efficiently catalyze 2″-O-apiosylation of flavonoid glycosides, and exhibits strict selectivity towards UDP-apiose. We further solve the crystal structure of GuApiGT, determine a key sugar-binding motif (RLGSDH) through structural analysis and theoretical calculations, and obtain mutants with altered sugar selectivity through protein engineering. Moreover, we discover 121 candidate apiosyltransferase genes from Leguminosae plants, and identify the functions of 4 enzymes. Finally, we introduce GuApiGT and its upstream genes into Nicotiana benthamiana, and complete de novo biosynthesis of a series of flavonoid apiosides. This work reports an efficient phenolic apiosyltransferase, and reveals mechanisms for its sugar donor selectivity.

Characterization and structure-based protein engineering of a regiospecific saponin acetyltransferase from Astragalus membranaceus.

Acetylation contributes to the bioactivity of numerous medicinally important natural products. However, little is known about the acetylation on sugar moieties. Here we report a saponin acetyltransferase from Astragalus membranaceus. AmAT7-3 is discovered through a stepwise gene mining approach and characterized as the xylose C3'/C4'-O-acetyltransferse of astragaloside IV (1). To elucidate its catalytic mechanism, complex crystal structures of AmAT7-3/1 and AmAT7-3A310G/1 are obtained, which reveal a large active pocket decided by a specific sequence AADAG. Combining with QM/MM computation, the regiospecificity of AmAT7-3 is determined by sugar positioning modulated by surrounding amino acids including #A310 and #L290. Furthermore, a small mutant library is built using semi-rational design, where variants A310G and A310W are found to catalyze specific C3'-O and C4'-O acetylation, respectively. AmAT7-3 and its variants are also employed to acetylate other bioactive saponins. This work expands the understanding of saponin acetyltransferases, and provide efficient catalytic tools for saponin acetylation.

Cortical and subcortical mapping of the allostatic-interoceptive system in the human brain: replication and extension with 7 Tesla fMRI.

The brain continuously anticipates the energetic needs of the body and prepares to meet those needs before they arise, a process called allostasis. In support of allostasis, the brain continually models the internal state of the body, a process called interoception. Using published tract-tracing studies in non-human animals as a guide, we previously identified a large-scale system supporting allostasis and interoception in the human brain with functional magnetic resonance imaging (fMRI) at 3 Tesla. In the present study, we replicated and extended this system in humans using 7 Tesla fMRI (N = 91), improving the precision of subgenual and pregenual anterior cingulate topography as well as brainstem nuclei mapping. We verified over 90% of the anatomical connections in the hypothesized allostatic-interoceptive system observed in non-human animal research. We also identified functional connectivity hubs verified in tract-tracing studies but not previously detected using 3 Tesla fMRI. Finally, we demonstrated that individuals with stronger fMRI connectivity between system hubs self-reported greater interoceptive awareness, building on construct validity evidence from our earlier paper. Taken together, these results strengthen evidence for the existence of a whole-brain system supporting interoception in the service of allostasis and we consider the implications for mental and physical health.

Study on the calculation method and structural dynamic response of buried pipeline subjected to external explosion load based on multiphase coupling.

When the buried pipeline is subjected to the external explosion load, stress and deformation will occur. When the stress and deformation value exceed a specific range, it will affect the normal use of the buried pipeline. In this paper, a multiphase coupled model of pipeline, soil and fluid within the pipeline is established. The penalty function coupling method is used to describe the load between soil and pipeline and the fluid within the pipeline. By specifying the boundary conditions of the coupled system, the multiphase coupled global solution variational principle function of the soil-pipe-fluid is derived. According to the established multiphase coupled calculation method, the numerical simulation analysis of the response of pipeline to external explosion is carried out. The maximum error of the experimental and numerical simulation results is about 5%, which verifies the accuracy of the multiphase coupled calculation method. The soil-pipeline-fluid multiphase coupled numerical calculation model is established to analyze the response of the buried pipeline under the external explosion load. The results show that during the explosion shock wave propagating in the soil, the peak value of the explosion pressure in different positions in the soil of the gas pipeline is greater than that of the oil pipeline. As for the structural response, the maximum radial displacement value of the oil pipeline is reduced by 3.83 mm compared with the gas pipeline, the maximum stress value is reduced by 3.75%. The maximum radial displacement value of the pipeline with a fluid velocity of 1.5 m/s is 2.65 mm larger than that of the pipeline with a fluid velocity of 1 m/s, and the maximum stress value is increased by 5.72%. The deformation resistance and explosion resistance of the oil pipeline are both stronger than that of the gas pipeline. The higher the fluid velocity, the weaker the pipeline's resistance to deformation and explosion will be.

Identification and restoration of hydrological processes alteration during the fish spawning period.

The hydrological processes play an important role in stimulating fish spawning behavior. Changes in the natural hydrological processes will alter the populations and distribution of fish, which may have a negative impact on the native aquatic organisms. The aim of this study is to identify the alteration of the water rising process during the fish spawning period and to construct an ecological flow optimization model to restore the water rising conditions for fish reproduction. The Mann-Kendall test and the sliding t-test were used to detect the mutation year of the mean daily flow data sets in the fish spawning period in each monitoring year. Then the data sets can be divided into pre-altered and post-altered periods. The water rising process was characterized by the water rising processes count, the duration, the daily flow increase rate, the date of the water rising process, and the initial water rising flow. The changes in hydrological processes in the middle reaches of the Yangtze River were investigated by comparing the post-altered and pre-altered characteristic parameters. Furthermore, we integrated the statistical values of the five characteristic parameters in pre-altered into an ecological flow optimization model to simulate the natural water rising processes for the spawning of the Four Major Chinese Carps (FMCC) and Chinese Sturgeon (CS). The analysis showed that after the hydrological mutation year, the duration and the initial water rising flow in the FMCC spawning season were increased, with hydrological alteration degrees of 63.10% and 70.16%, respectively; however, the daily flow increase rate was significantly decreased, with hydrological alteration of 86.50%. During the CS spawning season, the water rising processes count and the initial water rising flow were dramatically altered parameters, with hydrological alteration degrees of 50.86% and 83.27%, respectively. The former parameter increased, but the latter decreased significantly in the post-altered period. To induce the spawning activity of FMCC and CS, appropriate ecological flows and hydrological parameters were proposed. These results showed that during the spawning seasons of FMCC and CS, the hydrological processes of the middle reaches of the Yangtze River changed significantly. Therefore, ecological flow must be ensured through ecological operation of upstream reservoirs to provide suitable spawning conditions in target fish spawning grounds.

Straight Manipulation Annealing in a Solvent Atmosphere for Quality-Improved Cs2AgBiBr6 Perovskites.

As a new-generation photoelectric material, perovskites have attracted researchers' attention due to their excellent optoelectronic properties. However, the existence of defects inevitably causes structural degradation and restricts their performance, which need to be further improved by post-treatment. At present, post-treatments mostly focus on non-contact treatments, which may constrain the effect since the influence on the perovskites caused by the direct contact is much more straightly. Therefore, we proposed an annealing strategy of straight manipulation in a solvent atmosphere with the assistance of polyimide (PI) tape for the perovskite post-treatment, due to the high heat resistance and less glue residual of this tape. It casts an influence on the perovskite directly, proving the possibility of the straight manipulation by operators, promoting the recrystallization of the perovskite grains and removing the impurity substance. The optimized Pb-free perovskite film exhibits a better X-ray sensitivity of 7.5 × 104 µC Gyair-1 cm-2 and a great detection limit of 47 nGyair s-1, which is comparable to advanced Pb-based perovskite X-ray detectors and all commercial ones. The new annealing strategy provides a facile, effective, and simple method to improve the perovskite quality, exhibiting the potential and harmlessness of the direct contact post-treatment, which paves the way for a broader application of perovskites.

Identification of FCER1G as a key gene in multiple myeloma based on weighted gene co-expression network analysis.

PURPOSE: Although the prognosis of multiple myeloma (MM) has remarkably improved with the emerge of novel agents, it remains incurable and relapses inevitably. The molecular mechanisms of MM have not been well-studied. Herein, this study aimed to identify key genes in MM. MATERIALS AND METHODS: The GSE39754 dataset was used to screen differentially expressed genes (DEGs) and construct a co-expression network. Hub nodes were identified in the protein and protein interaction (PPI) network. Datasets GSE13591 and GSE2658 were used to validate hub genes. Moreover, function and gene set enrichment analyses were performed to elucidate the molecular pathogenesis of MM. RESULTS: In this study, 11 genes were found to be hub genes in the co-expression network, among which four genes (CD68, FCER1G, PLAUR and LCP2) were also identified as hub nodes. In the test dataset GSE13591, CD68 and FCER1G were significantly downregulated in MM. Besides, the areas under the curve (AUCs) of CD68 and FCER1G were greater than 0.8 in both the training dataset and the test dataset. Our results also confirmed that FCER1G highly expressed patients had remarkably longer survival times in MM. Function and pathway enrichment analyses suggested that hub genes were associated with epithelial mesenchymal transition, TNF-α signaling via NF-κB and inflammatory response. GSEA in our study indicated that FCER1G participated in NK cell mediated cytotoxicity and the NOD-like receptor signaling pathway. CONCLUSION: Our study identified FCER1G as a key gene in MM, providing a novel biomarker and potential molecular mechanisms of MM for further studies.

Resting-state MRI functional connectivity as a neural correlate of multidomain lifestyle adherence in older adults at risk for Alzheimer's disease.

Prior research has demonstrated the importance of a healthy lifestyle to protect brain health and diminish dementia risk in later life. While a multidomain lifestyle provides an ecological perspective to voluntary engagement, its association with brain health is still under-investigated. Therefore, understanding the neural mechanisms underlying multidomain lifestyle engagement, particularly in older adults at risk for Alzheimer's disease (AD), gives valuable insights into providing lifestyle advice and intervention for those in need. The current study included 139 healthy older adults with familial risk for AD from the Prevent-AD longitudinal aging cohort. Self-reported exercise engagement, cognitive activity engagement, healthy diet adherence, and social activity engagement were included to examine potential phenotypes of an individual's lifestyle adherence. Two adherence profiles were discovered using data-driven clustering methodology [i.e., Adherence to healthy lifestyle (AL) group and Non-adherence to healthy lifestyle group]. Resting-state functional connectivity matrices and grey matter brain features obtained from magnetic resonance imaging were used to classify the two groups using a support vector machine (SVM). The SVM classifier was 75% accurate in separating groups. The features that show consistently high importance to the classification model were functional connectivity mainly between nodes located in different prior-defined functional networks. Most nodes were located in the default mode network, dorsal attention network, and visual network. Our results provide preliminary evidence of neurobiological characteristics underlying multidomain healthy lifestyle choices.

Effect of Nanomaterials on Gut Microbiota.

Nanomaterials are widely employed in everyday life, including food and engineering. Food additives on a nanoscale can enter the body via the digestive tract. The human gut microbiota is a dynamically balanced ecosystem composed of a multitude of microorganisms that play a crucial role in maintaining the proper physiological function of the digestive tract and the body's endocrine coordination. While the antibacterial capabilities of nanomaterials have received much interest in recent years, their impacts on gut microbiota ought to be cautioned about and explored. Nanomaterials exhibit good antibacterial capabilities in vitro. Animal studies have revealed that oral exposure to nanomaterials inhibits probiotic reproduction, stimulates the inflammatory response of the gut immune system, increases opportunistic infections, and changes the composition and structure of the gut microbiota. This article provides an overview of the impacts of nanomaterials, particularly titanium dioxide nanoparticles (TiO2 NPs), on the gut microbiota. It advances nanomaterial safety research and offers a scientific foundation for the prevention, control, and treatment of illnesses associated with gut microbiota abnormalities.

Correspondence of functional connectivity gradients across human isocortex, cerebellum, and hippocampus.

Gradient mapping is an important technique to summarize high dimensional biological features as low dimensional manifold representations in exploring brain structure-function relationships at various levels of the cerebral cortex. While recent studies have characterized the major gradients of functional connectivity in several brain structures using this technique, very few have systematically examined the correspondence of such gradients across structures under a common systems-level framework. Using resting-state functional magnetic resonance imaging, here we show that the organizing principles of the isocortex, and those of the cerebellum and hippocampus in relation to the isocortex, can be described using two common functional gradients. We suggest that the similarity in functional connectivity gradients across these structures can be meaningfully interpreted within a common computational framework based on the principles of predictive processing. The present results, and the specific hypotheses that they suggest, represent an important step toward an integrative account of brain function.