Processing Of Interoceptive Information Research Articles

Insula-cortico-subcortical networks predict interoceptive awareness and stress resilience

BackgroundInteroception, the neural sensing of visceral signals, and interoceptive awareness (IA), the conscious perception of interoception, are crucial for life survival functions and mental health. Resilience, the capacity to overcome adversity, has been associated with reduced interoceptive disturbances. Here, we sought evidence for our Insula Modular Active Control (IMAC) model that suggest that the insula, a brain region specialized in the processing of interoceptive information, realizes IA and contributes to resilience and mental health via cortico-subcortical connections. Methods64 healthy participants (32 females; ages 18–34 years) answered questionnaires that assess IA and resilience. Mental health was evaluated with the Beck Depression Inventory II that assesses depressive mood. Participants also underwent a 15 minute resting-state functional resonance imaging session. Pearson correlations and mediation analyses were used to investigate the relationship between IA and resilience and their contributions to depressive mood. We then performed insula seed-based functional connectivity analyzes to identify insula networks involved in IA, resilience and depressive mood. ResultsWe first demonstrated that resilience mediates the relationship between IA and depressive mood. Second, shared and distinct intra-insula, insula-cortical and insula-subcortical networks were associated with IA, resilience and also predicted the degree of experienced depressive mood. Third, while resilience was associated with stronger insula-precuneus, insula-cerebellum and insula-prefrontal networks, IA was linked with stronger intra-insula, insula-striatum and insula-motor networks. ConclusionsOur findings help understand the roles of insula-cortico-subcortical networks in IA and resilience. These results also highlight the potential use of insula networks as biomarkers for depression prediction.

Sensory integration in interoception: Interplay between top-down and bottom-up processing

Although the neural systems supporting interoception have been outlined in general, the exact processes underlying the integration of visceral signals still await research. Based on the predictive coding concept, we aimed to reveal the neural networks responsible for the bottom-up (stimulus-dependent) and top-down (model-dependent) processing of interoceptive information. In a study of 30 female participants, we utilized two classical body perception experiments—the rubber hand illusion and a heartbeat detection task (cardioception), with the latter being implemented in fMRI settings. We interpreted a stronger rubber hand illusion, as measured by higher proprioceptive drift, as a tendency to rely on actual sensory experience, i.e., bottom-up processing, while lower proprioceptive drift served as an indicator of the prevalence of top-down, model-based influences. To reveal the bottom-up and top–down processes in cardioception, we performed a seed-based connectivity analysis of the heartbeat detection task, using as seeds the areas with known roles in sensory integration and entering proprioceptive drift as a covariate. The results revealed a left thalamus-dependent network positively associated with proprioceptive drift (bottom-up processing) and a left amygdala-dependent network negatively associated with drift (top-down processing). Bottom-up processing was related to thalamic connectivity with the left frontal operculum and anterior insula, anterior cingulate cortex, hypothalamus, right planum polare and right inferior frontal gyrus. Top-down processing was related to amygdalar connectivity with the rostral prefrontal cortex and an area involving the left frontal opercular and anterior insular cortex, with the latter area being an intersection of the two networks. Thus, we revealed the neural mechanisms underlying the integration of interoceptive information through the interaction between the current sensory experience and internal models.

Intrinsic functional brain connectivity patterns underlying enhanced interoceptive sensibility

BackgroundCumulative evidence has suggested that brain regions including the bilateral insula and the anterior cingulate cortex play critical roles in the processing of interoceptive information. However, the brain functional connectivity patterns underlying interoceptive sensibility (IS) and their role in the relationship between IS and self-reported bodily symptoms remain unknown. We aimed to investigate the intrinsic functional connectivity patterns associated with IS and how this modulates the relationship between IS and self-reported bodily symptoms. MethodsResting-state functional magnetic resonance imaging was used to test the intrinsic large-scale functional connectivity in 459 healthy subjects. IS and self-reported bodily symptoms were assessed by questionnaires. ResultsIndividuals with greater IS had a stronger tendency to report bodily symptoms. Higher IS was correlated with decreased ventral anterior insula-superior temporal gyrus, dorsal anterior cingulate cortex-middle frontal cortex and amygdala-medioventral occipital cortex connectivity. The large-scale functional connectivity of cingulo-opercular task control network (CON)-default mode network, CON-subcortical network and CON-dorsal attention network moderated the association between IS and bodily symptoms. LimitationsThe Body Perception Questionnaire mainly reflects the self-perceived tendency to focus on negatively-valenced interoceptive sensations. Future research should distinguish neutral and negative IS in order to make the definition of IS clearer. ConclusionsThis study suggests that IS may be related to impaired intrinsic functional connectivity between brain areas related to multisensory integration and cognitive-affective control, resulting in increased vigilance-attention to bodily signals. These findings offer new empirical evidence for a better understanding of the intricate relationships between interoception and symptom reporting.

The Neuroscience of Maternal Love

Maternal love, which is at the core of maternal behavior, is essential for the mother–infant attachment relationship and is important for an infant’s development and mental health. In addition, maternal love plays important roles in promoting not only the infant’s resilience, but also the mother’s. Therefore, it is crucial to clarify the neural basis of maternal love and related behaviors to understand both normal mothering and abusive and neglectful mothering. Here, we have reviewed our recent neuroimaging studies on the neural basis of maternal love and behavior. Based on the assumption that a mother’s love for her infant is invariant in any situation, we found that a limited number of the mother’s brain areas were specifically involved in maternal love, namely, the orbitofrontal cortex (OFC), striatum, anterior insula, and periaqueductal gray, suggesting that maternal love is mediated via integration of the two major neural systems in the OFC: the dopamine reward system (the OFC and striatum) and the interoceptive information processing system (the OFC, insula, and periaqueductal gray). Additionally, when the mother viewed her own infant in distress, there was significant activation in the dorsal OFC, dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, dorsomedial prefrontal cortex, dorsal anterior cingulate cortex, posterior cingulate cortex, caudate nucleus, supplementary motor area, and posterior superior temporal sulcus/temporoparietal junction. These results suggest that a highly elaborate neural mechanism, based on the neural basis of maternal love, mediates the diverse and complex maternal behaviors that mothers engage in when raising and protecting their own infants.

Insular cortex activity and the evocation of laughter.

The insular cortex is fundamentally involved in the processing of interoceptive information. It has been postulated that the integrative monitoring of the bodily responses to environmental stimuli is crucial for the recognition and experience of emotions. Because emotional arousal is known to be closely coupled to functions of the anterior insula, we suspected laughter to be associated primarily with neuronal activity in this region. An anatomically constrained re-analysis of our imaging data pertaining to ticklish laughter, to inhibited ticklish laughter, and to voluntary laughter revealed regional differences in the levels of neuronal activity in the posterior and mid-/anterior portions of the insula. Ticklish laughter was associated specifically with right ventral anterior insular activity, which was not detected under the other two conditions. Hence, apparently, only laughter that is evoked as an emotional response bears the signature of autonomic arousal in the insular cortex.

Probing the Interoceptive Network by Listening to Heartbeats: An fMRI Study.

Exposure to cues of homeostatic relevance (i.e. heartbeats) is supposed to increase the allocation of attentional resources towards the cue, due to its importance for self-regulatory, interoceptive processes. This functional magnetic resonance imaging (fMRI) study aimed at determining whether listening to heartbeats is accompanied by activation in brain areas associated with interoception, particularly the insular cortex. Brain activity was measured with fMRI during cue-exposure in 36 subjects while listening to heartbeats vs. sinus tones. Autonomic markers (skin conductance) and subjective measures of state and trait anxiety were assessed. Stimulation with heartbeat sounds triggered activation in brain areas commonly associated with the processing of interoceptive information, including bilateral insular cortices, the inferior frontal operculum, and the middle frontal gyrus. A psychophysiological interaction analysis indicated a functional connectivity between the middle frontal gyrus (seed region) and bilateral insular cortices, the left amygdala and the supplementary motor area. The magnitude of neural activation in the right anterior insular cortex was positively associated with autonomic arousal. The present findings indicate that listening to heartbeats induced activity in areas of the interoception network as well as changes in psychophysiological arousal and subjective emotional experience. As this approach constitutes a promising method for studying interoception in the fMRI environment, a clinical application in anxiety prone populations should be addressed by future studies.