Neural correlates of interoceptive accuracy: Beyond cardioception.

Area of Science:

• Neuroscience
• Psychology
• Physiology

Background:

• Interoceptive accuracy (IAc), assessing bodily signals, is increasingly studied, often focusing on cardiac signals and non-ecological methods.
• The anterior insular cortex is typically identified as the primary brain region associated with IAc.
• A gap exists in brain imaging research exploring IAc in more ecologically valid contexts.

Purpose of the Study:

• To investigate brain regions associated with trial-by-trial variations in interoceptive accuracy using an ecological approach.
• To explore the neural underpinnings of how individuals' precision in sensing their internal bodily state changes moment-to-moment.
• To examine the relationship between physiological responses and subjective ratings of bodily reactions in an emotional context.

Main Methods:

• Utilized a novel ecological functional magnetic resonance imaging (fMRI) task where participants rated bodily reactions to emotional pictures.
• Recorded skin conductance response (SCR) as an objective measure of physiological arousal.
• Employed fMRI to model brain activity based on SCR, subjective ratings, and their product (proxy for IAc) on a trial-by-trial basis.

Main Results:

• Found increased activity in the dorsomedial prefrontal cortex (dmPFC) correlating with decreased interoceptive accuracy.
• Identified a general error processing mechanism within the dmPFC, not specific to interoception.
• Demonstrated that intraindividual fluctuations in IAc are linked to dmPFC activation patterns.

Conclusions:

• The study highlights the dmPFC's role in processing errors related to interoceptive accuracy variations.
• Results support the predictive coding framework, suggesting IAc deficits may involve impaired mismatch processing between interoceptive signals and predictions.
• Findings have clinical implications, potentially explaining IAc impairments in various conditions through a prediction error lens.