Universal Explanation Research Articles

Is Component-Specific Antibody Testing Sufficient to Replace the Oral Food Challenge in the Diagnostics of Peanut-Sensitized Children? A Proof-of-Concept Study.

(1) Peanut allergy is associated with high risk of anaphylaxis which could be prevented by oral immunotherapy. Patients eligible for immunotherapy are selected on the basis of a food challenge, although currently the assessment of antibodies against main peanut molecules (Ara h 1, 2, 3 and 6) is thought to be another option. (2) The current study assessed the relationship between the mentioned antibodies, challenge outcomes, skin tests and some other parameters in peanut-sensitized children. It involved 74 children, divided into two groups, based on their response to a food challenge. (3) Both groups differed in results of skin tests, levels of component-specific antibodies and peanut exposure history. The antibody levels were then used to calculate thresholds for prediction of challenge results or symptom severity. While the antibody-based challenge prediction revealed statistical significance, it failed in cases of severe symptoms. Furthermore, no significant correlation was observed between antibody levels, symptom-eliciting doses and the risk of severe anaphylaxis. Although in some patients it could result from interference with IgG4, the latter would not be a universal explanation of this phenomenon. (4) Despite some limitations, antibody-based screening may be an alternative to the food challenge, although its clinical relevance still requires further studies.

A modified cosmic brane proposal for holographic Renyi entropy

We propose a new formula for computing holographic Renyi entropies in the presence of multiple extremal surfaces. Our proposal is based on computing the wave function in the basis of fixed-area states and assuming a diagonal approximation for the Renyi entropy. For Renyi index n ≥ 1, our proposal agrees with the existing cosmic brane proposal for holographic Renyi entropy. For n < 1, however, our proposal predicts a new phase with leading order (in Newton’s constant G) corrections to the cosmic brane proposal, even far from entanglement phase transitions and when bulk quantum corrections are unimportant. Recast in terms of optimization over fixed-area states, the difference between the two proposals can be understood to come from the order of optimization: for n < 1, the cosmic brane proposal is a minimax prescription whereas our proposal is a maximin prescription. We demonstrate the presence of such leading order corrections using illustrative examples. In particular, our proposal reproduces existing results in the literature for the PSSY model and high-energy eigenstates, providing a universal explanation for previously found leading order corrections to the n < 1 Renyi entropies.

The Gompertz Law emerges naturally from the inter-dependencies between sub-components in complex organisms

Understanding and facilitating healthy aging has become a major goal in medical research and it is becoming increasingly acknowledged that there is a need for understanding the aging phenotype as a whole rather than focusing on individual factors. Here, we provide a universal explanation for the emergence of Gompertzian mortality patterns using a systems approach to describe aging in complex organisms that consist of many inter-dependent subsystems. Our model relates to the Sufficient-Component Cause Model, widely used within the field of epidemiology, and we show that including inter-dependencies between subsystems and modeling the temporal evolution of subsystem failure results in Gompertizan mortality on the population level. Our model also provides temporal trajectories of mortality-risk for the individual. These results may give insight into understanding how biological age evolves stochastically within the individual, and how this in turn leads to a natural heterogeneity of biological age in a population.

Patterns and drivers of avian taxonomic and phylogenetic beta diversity in China vary across geographical backgrounds and dispersal abilities.

Geographical background and dispersal ability may strongly influence assemblage dissimilarity; however, these aspects have generally been overlooked in previous large-scale beta diversity studies. Here, we examined whether the patterns and drivers of taxonomic beta diversity (TBD) and phylogenetic beta diversity (PBD) of breeding birds in China vary across (1) regions on both sides of the Hu Line, which demarcates China's topographical, climatic, economic, and social patterns, and (2) species with different dispersal ability. TBD and PBD were calculated and partitioned into turnover and nestedness components using a moving window approach. Variables representing climate, habitat heterogeneity, and habitat quality were employed to evaluate the effects of environmental filtering. Spatial distance was considered to assess the impact of dispersal limitation. Variance partitioning analysis was applied to assess the relative roles of these variables. In general, the values of TBD and PBD were high in mountainous areas and were largely determined by environmental filtering. However, different dominant environmental filters on either side of the Hu Line led to divergent beta diversity patterns. Specifically, climate-driven species turnover and habitat heterogeneity-related species nestedness dominated the regions east and west of the line, respectively. Additionally, bird species with stronger dispersal ability were more susceptible to environmental filtering, resulting in more homogeneous assemblages. Our results indicated that regions with distinctive geographical backgrounds may present different ecological factors that lead to divergent assemblage dissimilarity patterns, and dispersal ability determines the response of assemblages to these ecological factors. Identifying a single universal explanation for the observed pattern without considering these aspects may lead to simplistic or incomplete conclusions. Consequently, a comprehensive understanding of large-scale beta diversity patterns and effective planning of conservation strategies necessitate the consideration of both geographical background and species dispersal ability.

VLA monitoring of LS V +44 17 reveals scatter in the X-ray–radio correlation of Be/X-ray binaries

ABSTRACT LS V +44 17 is a persistent Be/X-ray binary (BeXRB) that displayed a bright, double-peaked period of X-ray activity in late 2022/early 2023. We present a radio monitoring campaign of this outburst using the Very Large Array. Radio emission was detected, but only during the second, X-ray brightest, peak, where the radio emission followed the rise and decay of the X-ray outburst. LS V +44 17 is therefore the third neutron star BeXRB with a radio counterpart. Similar to the other two systems (Swift J0243.6+6124 and 1A 0535+262), its X-ray and radio luminosity are correlated: we measure a power-law slope $\beta = 1.25^{+0.64}_{-0.30}$ and a radio luminosity of LR = (1.6 ± 0.2) × 1026 erg s−1 at a 0.5–10 keV X-ray luminosity of 2 × 1036 erg s−1 (i.e. $\sim 1~{{\ \rm per\ cent}}$LEdd). This correlation index is slightly steeper than measured for the other two sources, while its radio luminosity is higher. We discuss the origin of the radio emission, specifically in the context of jet launching. The enhanced radio brightness compared to the other two BeXRBs is the first evidence of scatter in the giant BeXRB outburst X-ray–radio correlation, similar to the scatter observed in subclasses of low-mass X-ray binaries. While a universal explanation for such scatter is not known, we explore several options: we conclude that the three sources do not follow proposed scalings between jet power and neutron star spin or magnetic field, and instead briefly explore the effects that ambient stellar wind density may have on BeXRB jet luminosity.

Convergent Anuran Middle Ear Loss Lacks a Universal, Adaptive Explanation

Introduction: Shared selection pressures often explain convergent trait loss, yet anurans (frogs and toads) have lost their middle ears at least 38 times with no obvious shared selection pressures unifying “earless” taxa. Anuran tympanic middle ear loss is especially perplexing because acoustic communication is dominant within Anura and tympanic middle ears enhance airborne hearing in most tetrapods. Methods: Here, we use phylogenetic comparative methods to examine whether particular geographic ranges, microhabitats, activity patterns, or aspects of acoustic communication are associated with anuran tympanic middle ear loss. Results: Although we find some differences between the geographic ranges of eared and earless species on average, there is plenty of overlap between the geographic distributions of eared and earless species. Additionally, we find a higher prevalence of diurnality in earless species, but not all earless species are diurnal. We find no universal adaptive explanation for the many instances of anuran tympanic middle ear loss. Conclusion: The puzzling lack of universally shared selection pressures among earless species motivates discussion of alternative hypotheses, including genetic or developmental constraints, and the possibility that tympanic middle ear loss is maladaptive.

Evidence for a trade-off between growth rate and xylem cavitation resistance in Callitris rhomboidea.

The ideal plant water transport system is one that features high efficiency and resistance to drought-induced damage (xylem cavitation), however species rarely possess both. This may be explained by trade-offs between traits, yet thus far, no proposed trade-off has offered a universal explanation for the lack water transport systems that are both highly drought-resistant and highly efficient. Here we find evidence for a new trade-off, between growth rate and resistance to xylem cavitation, in the canopies of a drought-resistant tree species (Callitris rhomboidea). Wide variation in cavitation resistance (P50) was found in distal branch tips (< 2mm in diameter), converging to low variation in P50 in larger diameter stems (> 2mm). We found a significant correlation between cavitation resistance and distal branchlet internode length across branch tips in C. rhomboidea canopies. Branchlets with long internodes (8mm or longer) were significantly more vulnerable to drought-induced xylem cavitation than shorter internodes (4mm or shorter). This suggests that varying growth rates, leading to differences in internode length, drive differences in cavitation resistance in C. rhomboidea trees. The only distinct anatomical difference found between internodes was the pith size, with the average pith to xylem area in long internodes, 5x greater than in short internodes. Understanding whether this trade-off exists within and between species will help us to uncover what drives and limits drought resistance across the world's flora.

Revisiting key debates in the study of nationalism

The purpose of this article is to lay out the debates and arguments around three key broader issues that dominate nationalism studies: (a) the meaning of a nation and nationalism and the relationship between political and cultural nationalism; (b) the origins and character of nations and nationalism; and (c) the civic-ethnic dichotomy and the relationship between nationalism and liberalism. It does not aim to provide definitive answers to the complex problems associated with nations and nationalism but rather to provide an overview of these debates by examining the existing literature on nations and nationalism. The final section discusses the position of new approaches to nations and nationalism and how they have problematised the key assumptions of the mainstream understanding of nationalism. The article, in light of an overview of the literature, draws four important conclusions. First, the academic journey of nationalism has reached a stage where the current consensus is that nations are socially constructed and historically contingent phenomena, and the current focus of the scholarship is on looking at the intersection between the cultural and political aspects of nationalism. Second, nations and nationalism possess a multifaceted character with particularity, subjectivity, and relativity as their defining features, representing that a single, universal explanation of nationalism is neither feasible nor morally desirable. Third, to understand the multiplicity and diversity of nations and nationalism and the ways in which elements of this multidimensionality intersect, it is necessary to treat them as open-ended, unstable, dispersed, protean, particular, and contingent phenomena. Finally, deep contestation constitutes a source of power and strength for nations and nationalism.

Psychosis and psychedelics: Historical entanglements and contemporary contrasts.

Experiences of psychedelics and psychosis were deeply entangled in scientific practices in the mid-20th century, from uses of psychedelic drugs that could model psychosis, to detailed phenomenological comparisons of endogenous and drug-induced madness. After the moral panic of the 1960s shut down psychedelic research, however, these two phenomena became disentangled. In the decades following, the science of psychosis transformed, shedding the language of psychoanalysis, and adopting the new scientific veneer of psychiatry. Today, as psychedelic science re-emerges, the research programs surrounding psychosis and psychedelics now stand in stark contrast. Here, I look closely at how these research programs respond to questions related to what is worth measuring, what is worth investigating, and how we ought to respond to these experiences. This comparison reveals radically different assumptions and values that guide each research paradigm and shape clinical practice. While psychedelic research often includes scales that seek to capture experiences of mysticism, meaningfulness, and ego dissolution, research related to psychosis focuses on the measurement of pathological symptoms and functioning. Research into psychosis primarily seeks universal and reductionist causal explanations and interventions, while psychedelic research embraces the importance of set and setting in shaping unique experiences. Responses to psychedelic crisis involve warmth, compassion, and support, while responses to psychotic experiences often involve restraint, seclusion, and weapons. I argue that these differences contain important lessons for psychiatry. However, as psychedelic research struggles to meet regulatory requirements and fit within the paradigm of evidence-based medicine, these differences may quickly dissolve.

Exceptions to the rule: Relative roles of time, diversification rates and regional energy in shaping the inverse latitudinal diversity gradient

AbstractAimInverse latitudinal diversity gradients (i‐LDGs), whereby regional richness peaks outside the tropics, have rarely been investigated, and their causes remain unclear. Here, we investigate three prominent explanations, postulating that species‐rich regions have had: (1) longer time to accumulate species; (2) faster diversification; and (3) more energy to support species‐rich communities. These mechanisms have been shown to explain the tropical megadiversity, and we examine whether they can also explain i‐LDG.LocationGlobal.Time periodContemporary.Major taxa studiedAmphibians, birds and mammals.MethodsWe estimated the time for species accumulation, regional diversification rates and regional energy for six tetrapod taxa (c. 800 species). We quantified the relative effects and interactions among these three classes of variables, using variance partitioning, and confirmed the results across alternative metrics for time (community phylometrics and BioGeoBEARS), diversification rates (BAMM and DR) and regional energy (past and current temperature, and productivity).ResultsAlthough regional richness across each of the six taxa peaked in the temperate region, it varied markedly across hemispheres and continents. The effects of time, diversification rates and regional energy varied greatly from one taxon to another, but high diversification rates generally emerged as the best predictor of high regional richness. The effects of time and regional energy were limited, with the exception of salamanders and cetaceans.Main conclusionsTogether, our results indicate that the causes of i‐LDG are highly taxon specific. Consequently, large‐scale richness gradients might not have a universal explanation, and different causal pathways might converge on similar gradients. Moreover, regional diversification rates might vary dramatically between similar environments and, depending on the taxon, regional richness might or might not depend on the time for species accumulation. Collectively, these results underscore the complexity behind the formation of richness gradients, which might involve a symphony of variations on the interplay of time, diversification rates and regional energy.

‘Missing girls’ in interwar Poland: child sex ratios and their correlates across multiple borderlands

ABSTRACT Our testing of the relationship between child sex ratios (CSRs) and demographic, socioeconomic, and cultural diversity across nearly 300 districts of interwar Poland around 1931 yields a picture more complicated than common explanations of high masculinization of offspring. In line with existing literature, we found district-level CSRs to be positively associated with the extent of agriculture but negatively related to the relative spread of female employment outside farming and less hierarchical gender and generational household arrangements. At the same time, several of the classical modernization variables (e.g. industrialization, urbanization, female literacy or fertility) either did not result in lower sex ratios or turned out irrelevant. In this article, we attempt to reconcile these diverging results by putting them in the context of the country’s relative backwardness, the specific labor demands created by modernization, and the structure of the agricultural labor market. Altogether, our results add a new stimulus to study gender discrimination in infancy and childhood in East-Central European context and to contemplate universal explanations thereof.

Biochemistry and Molecular Basis of Intracellular Flavonoid Transport in Plants.

Flavonoids are a biochemically diverse group of specialized metabolites in plants that are derived from phenylalanine. While the biosynthesis of the flavonoid aglycone is highly conserved across species and well characterized, numerous species-specific decoration steps and their relevance remained largely unexplored. The flavonoid biosynthesis takes place at the cytosolic side of the endoplasmatic reticulum (ER), but accumulation of various flavonoids was observed in the central vacuole. A universal explanation for the subcellular transport of flavonoids has eluded researchers for decades. Current knowledge suggests that a glutathione S-transferase-like protein (ligandin) protects anthocyanins and potentially proanthocyanidin precursors during the transport to the central vacuole. ABCC transporters and to a lower extend MATE transporters sequester anthocyanins into the vacuole. Glycosides of specific proanthocyanidin precursors are sequestered through MATE transporters. A P-ATPase in the tonoplast and potentially other proteins generate the proton gradient that is required for the MATE-mediated antiport. Vesicle-mediated transport of flavonoids from the ER to the vacuole is considered as an alternative or additional route.

Disparagement humor: Could laughter dissolve hostility?

<p id=C6>Disparagement humor refers to communication that derogates or denigrates a certain target but elicits amusement. Blending two contradictory elements in terms of social approvability, the paradox of disparagement humor has sparked three major questions: how does amusement arise from disparagement? What determines whether an attempt at disparagement humor is perceived to be funny or offensive? What are the unique aftereffects of this fusion? Four major theoretical frameworks have been proposed to understand the psychological mechanism of disparagement humor. From a psychoanalytic perspective, relief theory suggests that the entertainment of humor comes from the catharsis of hostility. From an intergroup perspective, superiority theory suggests that the feeling of superiority generated by the disparagement of others leads to humorous experiences. From a cognitive perspective, incongruity-resolution theory suggests that humor derives from the resolution of incongruencies. Additionally, from a cognitive perspective, to provide a more accurate and universal explanation for humor than incongruity-resolution theory, benign violation theory suggests that humor comes from appraising something as both a violation and benign. Among the theories, the former two address the unique motivational factors underlying disparagement humor, while the latter two provide universal cognitive models to explain all humor, including disparagement humor. Thus, a motivational cognition model proposed later in the article could effectively depict an integrated picture of the psychological mechanism of disparagement humor. However, people do not necessarily find disparagement humor funny; sometimes it is offensive. Factors influencing the reception of disparagement humor include group identities and attitudes, psychological distance between the recipient and the object of derogation, and personal and cultural differences. The social effects of humor and derogatory comments are usually opposite, but the fusion of the two can produce unique outcomes. First, it can serve as a prejudice releaser by creating a social norm that allows the expression of prejudice, which is normally forbidden in modern society. In addition, the use of disparagement humor can serve to reinforce social hierarchies by functioning as a legitimizing myth that justifies expressions of social dominance motivations. Conversely, when disparagement humor is used by a disadvantaged social group to subvert an inequitable social hierarchy, the strategy of covering an insubordinate message with humor may encourage the expression of subversion and thus promote social equity. Finally, the impacts of disparagement humor on interpersonal interactions are inconsistent due to the contradictory effects of disparagement and humor. After reviewing the relevant theories and studies, we propose an integrated process model of disparagement. The model takes benign violation theory as its fundamental framework, dividing the completion of disparagement humor into three parts: first, the expresser delivers disparagement; second, the audience evaluates the disparagement as benign; and third, a sense of humor is produced. The model also integrates the motivational perspectives of relief theory and superiority theory by addressing motivational factors in the delivery and evaluation process. In addition, the model displays the retroaction of disparagement humor’s aftereffects on its delivery and evaluation by combining the prejudice-releaser and legitimizing-myth role of disparagement humor. As it depicts a comprehensive process and captures the dynamism of disparagement humor, the model can hopefully serve as a scaffold for future research. It is also important for future research to explore the negative effects of disparagement humor. Moreover, the potentially positive effects of disparagement humor on intergroup relations and social justice when used by disadvantaged groups to fight social injustice merit investigation. Finally, it could be rewarding to study the cultural distinctiveness of disparagement humor in certain aspects of Chinese culture, such as its essential foreignness and prosperous localization, the commercialization trend of disparagement jokes, and the specifically Chinese content conveyed and popularized by disparagement humor.

AC interference impact on EIS assessment of organic coatings using dummy cells, calibration foils and field exposed coated samples

Field application of EIS to intact and scarcely degraded high-performance protective coatings is challenging because of ambient electromagnetic fields, which cause stochastic variations in the phase angle and, to a lesser extent, in the impedance modulus of the coating spectra. AC interferences with amplitudes between 10 and 800 mV were induced on dummy cells and calibration foils to systematically investigate the effects of interference impact on the accuracy and precision of measurements with the EIS setup intended for use on coatings in the field. For EIS signal amplitudes between 10 and 250 mV and the AC interference amplitudes ≤250 mV, the measurement accuracy and precision were limited by the synergistic influence of the AC interferences and the imprecision of the EIS instrument. For systems with impedance ≥ GΩ, the accuracy of the impedance logarithm was 97.8% at signal amplitudes ≥190 mV, and the precision increased from nearly 95% to 99% as the signal amplitude increased from 10 to 150 mV, indicating that very accurate and precise measurements can be obtained at higher signal amplitudes. An example of EIS measurements on coated samples exposed in the area of AC railway interferences is given. Although the quantitative conclusions may be instrument specific, they reflect well the declared capabilities of today's high-end EIS devices. The universal explanation is given in the context of equivalent circuit theory of the observed scatter in the EIS spectral data. The coating assessment was commented on in terms of the unique properties of the mean and relative standard deviation of impedance expressed on the logarithmic scale.

Minimum Leaf Conductance (g min) Is Higher in the Treeline of Pinus uncinata Ram. in the Pyrenees: Michaelis' Hypothesis Revisited.

The search for a universal explanation of the altitudinal limit determined by the alpine treeline has given rise to different hypotheses. In this study, we revisited Michaelis’ hypothesis which proposed that an inadequate “ripening” of the cuticle caused a greater transpiration rate during winter in the treeline. However, few studies with different explanations have investigated the role of passive mechanisms of needles for protecting against water loss during winter in conifers at the treeline. To shed light on this, the cuticular transpiration barrier was studied in the transition from subalpine Pinus uncinata forests to alpine tundra at the upper limit of the species in the Pyrenees. This upper limit of P. uncinata was selected here as an example of the ecotones formed by conifers in the temperate mountains of the northern hemisphere. Our study showed that minimum leaf conductance in needles from upper limit specimens was higher than those measured in specimens living in the lower levels of the sub-alpine forest and also displayed lower cuticle thickness values, which should reinforce the seminal hypothesis by Michaelis. Our study showed clear evidence that supports the inadequate development of needle cuticles as one of the factors that lead to increased transpirational water losses during winter and, consequently, a higher risk of suffering frost drought.

Transition between growth of dense and porous films: theory of dual-layer SEI.

The formation of passivating films is a common aging phenomenon, for example in weathering of rocks, silicon, and metals. In many cases, a dual-layer structure with a dense inner and a porous outer layer emerges. However, the origin of this dual-layer growth is so far not fully understood. In this work, a continuum model is developed, which describes the morphology evolution of the solid-electrolyte interphase (SEI) in lithium-ion batteries. Transport through the SEI and a growth reaction governed by the SEI surface energies are modelled. In agreement with experiments, this theory predicts that SEI grows initially as a dense film and subsequently as a porous layer. This dynamic phase transition is driven by the slowing down of electron transport as the film thickens. Thereby, the model offers a universal explanation for the emergence of dual-layer structures in passivating films.

Forfeiting the paradigm of victimhood

This paper is a philosophical meta-discussion of the current culture in psychiatry and psychotherapy that focuses on trauma as the source and predominant determinant of a large number of psychiatric complaints. Such a culture leads to increasing, rather the decreasing, the destructive role of traumatization and victimization throughout the life experiences of those affected, and (as culture) is exemplified by increasing calls by influential psychiatrists to expand the interpretative role of trauma to virtually all our experiences of social inadequacy and personal hurt. We argue here, from a philosophical and psychiatric point of view, that the transactions, semantics and affects that psychiatry and psychotherapy are concerned with in cases of trauma and victimhood are negatively affected by the culture of using trauma as an alibi and a kind of universal explanation of psychological dysfunctionality and suffering. We also argue that, contrary to the current culture of a sort of idolatry of trauma, more consistent and philosophically informed approaches to psychiatric and psychotherapeutic intervention, based on a different interpretation of less-than-radically adverse life experiences, might in fact reduce both the clinical occurrence of traumatization and the actual adverse impact of self-perceived victimization and traumatization on the prospects for achieving the goal of ?the good life?.

Generalized Transport Equation for the Autocovariance Function of the Density Field and Mass Invariant in Star-forming Clouds

Abstract In this Letter, we study the evolution of the autocovariance function of density-field fluctuations in star-forming clouds and thus of the correlation length l c (ρ) of these fluctuations, which can be identified as the average size of the most correlated structures within the cloud. Generalizing the transport equation derived by Chandrasekhar for static, homogeneous turbulence, we show that the mass contained within these structures is an invariant, i.e., that the average mass contained in the most correlated structures remains constant during the evolution of the cloud, whatever dominates the global dynamics (gravity or turbulence). We show that the growing impact of gravity on the turbulent flow yields an increase of the variance of the density fluctuations and thus a drastic decrease of the correlation length. Theoretical relations are successfully compared to numerical simulations. This picture brings a robust support to star formation paradigms where the mass concentration in turbulent star-forming clouds evolves from initially large, weakly correlated filamentary structures to smaller, denser, more correlated ones, and eventually to small, tightly correlated, prestellar cores. We stress that the present results rely on a pure statistical approach of density fluctuations and do not involve any specific condition for the formation of prestellar cores. Interestingly enough, we show that, under average conditions typical of Milky-Way molecular clouds, this invariant average mass is about a solar mass, providing an appealing explanation for the apparent universality of the IMF in such environments.

Idealizations and analogies: Explaining critical phenomena

The “universality” of critical phenomena is much discussed in philosophy of scientific explanation, idealizations and philosophy of physics. Lange and Reutlinger recently opposed Batterman concerning the role of some deliberate distortions in unifying a large class of phenomena, regardless of microscopic constitution. They argue for an essential explanatory role for “commonalities” rather than that of idealizations. Building on Batterman's insight, this article aims to show that assessing the differences between the universality of critical phenomena and two paradigmatic cases of “commonality strategy”—the ideal gas model and the harmonic oscillator model—is necessary to avoid the objections raised by Lange and Reutlinger. Taking these universal explanations as benchmarks for critical phenomena reveals the importance of the different roles played by analogies underlying the use of the models. A special combination of physical and formal analogies allows one to explain the epistemic autonomy of the universality of critical phenomena through an explicative loop.

Bayesian brain in tinnitus: Computational modeling of three perceptual phenomena using a modified Hierarchical Gaussian Filter

Recently, Bayesian brain-based models emerged as a possible composite of existing theories, providing an universal explanation of tinnitus phenomena. Yet, the involvement of multiple synergistic mechanisms complicates the identification of behavioral and physiological evidence. To overcome this, an empirically tested computational model could support the evaluation of theoretical hypotheses by intrinsically encompassing different mechanisms. The aim of this work was to develop a generative computational tinnitus perception model based on the Bayesian brain concept. The behavioral responses of 46 tinnitus subjects who underwent ten consecutive residual inhibition assessments were used for model fitting. Our model was able to replicate the behavioral responses during residual inhibition in our cohort (median linear correlation coefficient of 0.79). Using the same model, we simulated two additional tinnitus phenomena: residual excitation and occurrence of tinnitus in non-tinnitus subjects after sensory deprivation. In the simulations, the trajectories of the model were consistent with previously obtained behavioral and physiological observations. Our work introduces generative computational modeling to the research field of tinnitus. It has the potential to quantitatively link experimental observations to theoretical hypotheses and to support the search for neural signatures of tinnitus by finding correlates between the latent variables of the model and measured physiological data.