A landmark 2021 study from the University of Sussex demonstrated that individuals with superior interoceptive accuracy—the ability to detect subtle bodily signals like heartbeats—showed markedly different neural responses during emotional processing. Their insular cortices activated with greater precision, and crucially, their emotional experiences appeared more nuanced and better regulated. This finding crystallized what researchers had suspected for decades: our awareness of internal bodily states isn't merely passive perception. It fundamentally shapes how we construct and regulate emotions.

Interoception, the sense of the body's internal milieu, has emerged as a critical nexus linking physiological processes to psychological experience. Unlike exteroceptive senses that monitor the external world, interoception tracks signals from visceral organs, vasculature, and smooth muscle—the continuous hum of cardiac rhythms, respiratory cycles, gastric contractions, and thermoregulatory fluctuations. These signals, once dismissed as background noise irrelevant to higher cognition, now appear central to emotional construction, self-awareness, and mental health.

The clinical implications are substantial. Aberrant interoceptive processing has been implicated in anxiety disorders, depression, eating disorders, alexithymia, and depersonalization-derealization disorder. Understanding the neural architecture and computational principles governing interoception opens novel therapeutic avenues—interventions that target not cognition or behavior directly, but the fundamental bodily awareness from which emotional experience emerges. This represents a paradigm shift in how we conceptualize emotion regulation: not as top-down cognitive control, but as calibration of the brain's predictive models of bodily states.

The neural infrastructure supporting interoception begins with specialized peripheral receptors distributed throughout visceral organs, blood vessels, and cardiac tissue. Mechanoreceptors, chemoreceptors, and thermoreceptors transduce information about blood pressure, blood chemistry, cardiac contractility, gastric distension, and immune activation. These signals travel via the vagus nerve and spinal afferents to converge initially in the nucleus tractus solitarius (NTS) in the brainstem—a critical relay station integrating multiple interoceptive channels.

From the NTS, interoceptive information ascends through the parabrachial nucleus to the ventromedial posterior nucleus of the thalamus, ultimately reaching the posterior and mid-insular cortex. A.D. Craig's seminal work mapped this pathway, demonstrating that the insula contains a hierarchically organized representation of bodily states. The posterior insula receives primary interoceptive input, while progressive integration occurs as information flows anteriorly. The anterior insula, particularly in the right hemisphere, appears to generate a unified, moment-to-moment representation of the body's internal condition—what Craig termed the 'sentient self.'

Individual differences in interoceptive processing are striking and clinically relevant. Researchers distinguish between interoceptive accuracy (objective detection ability, often measured via heartbeat counting tasks), interoceptive sensibility (self-reported attention to bodily signals), and interoceptive awareness (metacognitive correspondence between accuracy and sensibility). These dimensions are dissociable—an individual may report high attention to bodily signals while demonstrating poor objective detection, a pattern associated with heightened anxiety.

Neuroimaging studies reveal that interoceptive accuracy correlates with greater gray matter volume in the anterior insula and superior prediction error signaling in this region during interoceptive tasks. The right anterior insula shows particularly strong associations with cardiac interoceptive accuracy, while insular responses to respiratory signals show distinct spatial distributions. This suggests partially segregated cortical representations for different interoceptive modalities, though integration clearly occurs.

Beyond the insula, interoceptive processing recruits the anterior cingulate cortex (ACC), particularly its subgenual and pregenual divisions, which appear to integrate interoceptive signals with motivational and affective processing. The somatosensory cortices contribute to representing bodily states, while prefrontal regions modulate attention to interoceptive signals. This distributed network doesn't merely represent bodily states passively—it actively generates predictions about expected interoceptive input, a computational principle with profound implications for understanding emotion.

Takeaway

Interoception operates through a dedicated neural architecture culminating in the anterior insula, but individual differences in interoceptive accuracy versus sensibility create distinct vulnerability profiles for emotional dysfunction.

Constructionist theories of emotion, particularly Lisa Feldman Barrett's theory of constructed emotion, position interoception as foundational to emotional experience. In this framework, the brain doesn't passively detect emotions as discrete categories. Instead, it actively constructs emotional experiences by integrating interoceptive predictions with exteroceptive information and conceptual knowledge. Emotions emerge from the brain's interpretation of why the body is in a particular state, given the current context.

The predictive coding framework provides the computational architecture for this process. The brain continuously generates predictions about expected interoceptive input based on prior experience, current context, and active inferences about bodily states. Interoceptive prediction errors—discrepancies between predicted and actual visceral signals—drive learning and can trigger corrective actions. When the brain predicts increased cardiac output before a challenging task, and that prediction matches incoming signals, minimal prediction error occurs. When predictions fail, the brain must either update its model or act to change bodily states.

This framework reconceptualizes emotional experience as fundamentally embodied inference. The brain asks not 'what emotion am I feeling?' but 'what is the most likely cause of these bodily sensations given my current situation?' The answer—the constructed emotion—depends critically on both interoceptive input and the concepts available to categorize that input. A racing heart might be constructed as fear, excitement, or caffeine effects depending on contextual inference.

Critically, interoceptive precision—the brain's confidence in its interoceptive signals—modulates how heavily bodily information weights emotional construction. High interoceptive precision means the brain trusts incoming visceral signals and incorporates them strongly into emotional inference. Low precision means bodily signals are down-weighted, potentially leading to emotional experiences disconnected from physiological states. Altered precision weighting appears implicated in multiple psychiatric conditions.

Research by Manos Tsakiris and colleagues demonstrates that manipulating interoceptive precision experimentally affects emotional processing. When heartbeat signals are artificially amplified, participants show heightened emotional responses to affective stimuli. When cardiac signals are masked or rendered unpredictable, emotional processing is attenuated. This confirms that interoceptive signals aren't merely correlates of emotion—they are causal contributors to emotional construction, mediated by predictive processing mechanisms.

Takeaway

Emotions aren't detected but constructed through Bayesian inference, where interoceptive predictions and their errors shape subjective experience based on how confidently the brain weights bodily signals against contextual expectations.

The interoceptive framework generates specific, testable predictions about psychiatric pathology. Anxiety disorders, characterized by excessive threat-related emotional responding, show consistent associations with altered interoceptive processing. However, the pattern isn't simply 'more interoception equals more anxiety.' Instead, anxiety appears linked to elevated interoceptive sensibility—heightened attention and worry about bodily signals—combined with poor interoceptive accuracy. This mismatch creates a system primed to misinterpret normal bodily fluctuations as threatening.

Panic disorder exemplifies this dysfunction. Patients show catastrophic interpretations of benign interoceptive sensations, predicting heart attacks or imminent death from normal cardiac variability. Neuroimaging reveals heightened insular activation to interoceptive stimuli paired with reduced connectivity between insula and prefrontal regulatory regions. The predictive coding interpretation suggests excessive interoceptive precision—the brain treats every bodily signal as highly informative and potentially threatening, rather than appropriately down-weighting noisy or irrelevant fluctuations.

Interoceptive training interventions aim to recalibrate accuracy-sensibility correspondence. Heartbeat detection training with feedback improves interoceptive accuracy and, in preliminary studies, reduces anxiety symptoms. The mechanism likely involves teaching the brain to weight interoceptive signals appropriately—accurately detecting true signals while learning that most bodily fluctuations are non-threatening noise. Mindfulness-based interventions may work partially through similar mechanisms, shifting attention to bodily states in a non-judgmental, accepting manner that reduces catastrophic interpretation.

Alexithymia—difficulty identifying and describing emotions—and depersonalization-derealization disorder present the opposite pattern: diminished interoceptive processing associated with blunted emotional experience. These conditions may involve excessive down-weighting of interoceptive precision, rendering bodily signals phenomenologically silent. The subjective experience of emotional numbness or feeling disconnected from one's body may directly reflect this computational state—intact bodily signals that fail to influence conscious experience because the brain has learned to ignore them.

Emerging interventions target interoceptive deficits directly. Floatation-REST (Reduced Environmental Stimulation Therapy) enhances interoceptive signal-to-noise ratios by eliminating external stimuli, potentially recalibrating precision estimates. Virtual reality paradigms that provide contingent interoceptive feedback show promise for training bodily awareness. Pharmacological approaches targeting interoceptive pathways—including novel compounds affecting vagal signaling—represent another frontier. The interoceptive framework suggests that restoring appropriate precision weighting, not just changing thoughts or behaviors, may be fundamental to treating emotional dysregulation.

Takeaway

Anxiety and emotional numbing may represent opposite poles of interoceptive miscalibration—excessive or insufficient weighting of bodily signals—suggesting that precision recalibration, not just cognitive reframing, could be therapeutic.

The neuroscience of interoception fundamentally reframes emotional regulation as a problem of bodily inference rather than purely cognitive control. The brain's predictive models of internal states, the precision weighting of interoceptive signals, and the neural architecture from viscera to insula collectively determine how we construct and regulate emotional experience. This represents a substantive theoretical advance with genuine clinical utility.

For anxiety disorders, depression, alexithymia, and depersonalization, interoceptive dysfunction provides both a mechanistic account and therapeutic target. Interventions that recalibrate interoceptive accuracy, normalize precision weighting, or restore appropriate integration of bodily signals into emotional construction offer alternatives to approaches focused solely on thoughts or behaviors.

The research trajectory is clear: larger-scale trials of interoceptive interventions, better psychometric tools for assessing interoceptive dimensions, and integration of interoceptive measures into clinical assessment. The hidden sense underlying emotion regulation is hidden no longer—and its clinical potential is only beginning to be realized.