Lower Socioeconomic Position Is Associated with Greater Activity in and Integration within an Allostatic-Interoceptive Brain Network in Response to Affective Stimuli

The Mediating Role of Interoceptive Sensitivity in the Relationship between Physical Activity and Depression Symptoms in College Students

A substantial body of evidence indicates that neurological, psychological, and behavioral health issues are profoundly linked to interoceptive sensitivity. The present study aimed to identify the effects of interoceptive sensitivity on the relationship between physical activity and symptoms of depression in Chinese college students. This study employed a cross-sectional design using convenience sampling. An online self-reported survey was distributed to college students in China. The participants' interoceptive sensitivity, physical activity levels, and depressive symptoms were measured using the MAIA-2, IPAQ-SF, and PHQ-9, respectively. The mediating effect was tested via regression analysis and a parallel mediation model, with bootstrap confidence intervals for indirect effects. The results showed a significant negative correlation between physical activity and depression. A significant positive correlation was observed between physical activity and seven dimensions of interoceptive sensitivity. Conversely, interoceptive sensitivity exhibited a negative correlation with depression. The bootstrap mediation analysis showed that the "not distracting" and "trusting" dimensions of interoceptive sensitivity had significant indirect effects on the relationship between physical activity and depression, suggesting that physical activity might reduce depressive symptoms via these two interoceptive sensitivity dimensions. The findings suggest that interoceptive sensitivity should be integrated into therapeutic interventions, such as physical activity interventions, in the treatment of mental illnesses, particularly depression. Increasing physical activity levels, with a specific focus on enhancing interoceptive modulation, appears to be a promising approach for addressing depression in college students.

Emerging Theories of Allostatic-Interoceptive Overload in Neurodegeneration

Recent integrative multilevel models offer novel insights into the etiology and course of neurodegenerative conditions. The predictive coding of allostatic-interoception theory posits that the brain adapts to environmental demands by modulating internal bodily signals through the allostatic-interoceptive system. Specifically, a domain-general allostatic-interoceptive network exerts adaptive physiological control by fine-tuning initial top-down predictions and bottom-up peripheral signaling. In this context, adequate adaptation implies the minimization of prediction errors thereby optimizing energy expenditure. Abnormalities in top-down interoceptive predictions or peripheral signaling can trigger allostatic overload states, ultimately leading to dysregulated interoceptive and bodily systems (endocrine, immunological, circulatory, etc.). In this context, environmental stress, social determinants of health, and harmful exposomes (i.e., the cumulative life-course exposition to different environmental stressors) may interact with physiological and genetic factors, dysregulating allostatic interoception and precipitating neurodegenerative processes. We review the allostatic-interoceptive overload framework across different neurodegenerative diseases, particularly in the behavioral variant frontotemporal dementia (bvFTD). We describe how concepts of allostasis and interoception could be integrated with principles of predictive coding to explain how the brain optimizes adaptive responses, while maintaining physiological stability through feedback loops with multiple organismic systems. Then, we introduce the model of allostatic-interoceptive overload of bvFTD and discuss its implications for the understanding of pathophysiological and neurocognitive abnormalities in multiple neurodegenerative conditions.

Intrinsic timescales and predictive allostatic interoception in brain health and disease

The cognitive neuroscience of brain diseases faces challenges in understanding the complex relationship between brain structure and function, the heterogeneity of brain phenotypes, and the lack of dimensional and transnosological explanations. This perspective offers a framework combining the predictive coding theory of allostatic interoceptive overload (PAIO) and the intrinsic neural timescales (INT) theory to provide a more dynamic understanding of brain health in psychiatry and neurology. PAIO integrates allostasis and interoception to assess the interaction between internal patterns and environmental stressors, while INT shows that different brain regions operate on different intrinsic timescales. The allostatic overload can be understood as a failure of INT, which involves a breakdown of proper temporal integration and segregation. This can lead to dimensional disbalances between exteroceptive/interoceptive inputs across brain and whole-body levels (cardiometabolic, cardiovascular, inflammatory, immune). This approach offers new insights, presenting novel perspectives on brain spatiotemporal hierarchies and interactions. By integrating these theories, the paper opens innovative paths for studying brain health dynamics, which can inform future research in brain health and disease.

Exploring the relationship between multiple dimensions of subjective socioeconomic status and self-reported physical and mental health: the mediating role of affect

Introduction

This study aimed to investigate the predictive effects of two types of subjective socioeconomic status on self-reported physical and mental health. Specifically, we examined the MacArthur Scale (MacArthur) which measures perceived socioeconomic rank in the society and a novel scale called ComSim, which assessed how participants compared themselves socioeconomically to others coming from a similar socioeconomic background. We also considered the influence of income, education, and personal relative deprivation (PRD) in these analyses. Additionally, we explored whether these effects were mediated through negative and positive affect.

Methods

The data were collected through a cross-sectional, two-wave survey of 294 women and 294 men, with a mean age 41.6 years. Participants were recruited via an online platform.

Results

The results from multivariate regression models revealed that socioeconomic status measured with both the MacArthur Scale and ComSim significantly predicted both self-reported health measures, whereas income and education did not predict any of these measures in the full multivariate models. PRD only predicted self-reported mental health. Mediation analyses showed that negative and positive affect mediated the relationships between socioeconomic status measured by ComSim and self-reported health measures.

Discussion

These findings are discussed in the context of the similarity hypothesis of social comparison theory. The results underscore the importance of considering multiple dimensions when examining socioeconomic health disparities.

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.

The Affective Neuroscience of Poverty

Growing up in poverty is associated with a heightened risk for mental and physical health problems across the life span, and there is a growing recognition of the role that social determinants of health play in driving these outcomes and inequities. How do the social conditions of poverty get under the skin to influence biology, and through what mechanisms do the stressors of poverty generate risk for a broad range of health problems? The growing field examining the neuroscience of socioeconomic status (SES) proposes that the brain is an entry point or pathway through which poverty and adversity become embedded in biology to generate these disparities. To date, however, the majority of research on the neuroscience of SES has focused on cognitive or executive control processes. However, the relationship between SES and brain systems involved in affective or emotional processes may be especially important for understanding social determinants of health. Accordingly, this Special Focus on The Affective Neuroscience of Poverty invited contributions from authors examining the relationship between SES and brain systems involved in generating and regulating emotions. In this editorial introduction, we (a) provide an overview of the neuroscience of SES; (b) introduce each of the articles in this Special Focus; and (c) discuss the scientific, treatment, and policy implications of studying the affective neuroscience of poverty.