Modulation of emotional appraisal by false physiological feedback during fMRI

Insights into interoceptive and emotional processing: Lessons from studies on insular HD-tDCS

Interoception, the processing of internal bodily signals, is proposed as the fundamental mechanism underlying emotional experiences. Interoceptive and emotional processing appear distorted in psychiatric disorders. However, our understanding of the neural structures involved in both processes remains limited. To explore the feasibility of enhancing interoception and emotion, we conducted two studies using high-definition transcranial direct current stimulation (HD-tDCS) applied to the right anterior insula. In study one, we compared the effects of anodal HD-tDCS and sham tDCS on interoceptive abilities (sensibility, confidence, accuracy, emotional evaluation) in 52 healthy subjects. Study two additionally included physical activation through ergometer cycling at the beginning of HD-tDCS and examined changes in interoceptive and emotional processing in 39 healthy adults. In both studies, HD-tDCS was applied in a single-blind cross-over online design with two separate sessions. Study one yielded no significant effects of HD-tDCS on interoceptive dimensions. In study two, significant improvements in interoceptive sensibility and confidence were observed over time with physical preactivation, while no differential effects were found between sham and insula stimulation. The expected enhancement of interoceptive and emotional processing following insula stimulation was not observed. We conclude that HD-tDCS targeting the insula does not consistently increase interoceptive or emotional variables. The observed increase in interoceptive sensibility may be attributed to the activation of the interoceptive network through physical activity or training effects. Future research on HD-tDCS involving interoceptive network structures could benefit from protocols targeting larger regions within the network, rather than focusing solely on insula stimulation.

Data-driven analysis of whole-brain intrinsic connectivity in patients with chronic low back pain undergoing osteopathic manipulative treatment

BACKGROUND

Chronic Low Back Pain (cLBP) poses a significant health challenge, leading to functional disability and reduced quality of life. Osteopathic Manipulative Treatment (OMT) is emerging as a therapeutic option for cLBP, but the brain mechanisms underlying its analgesic effect remain unclear.

MATERIALS AND METHODS

Thirty cLBP patients were randomly exposed to either four weekly sessions of OMT (N=16) or Sham treatment (N=14). Resting-state Magnetic Resonance Imaging (rs-MRI) scans and pain perception questionnaires were collected before and after treatment. A voxel-wise, rs-fMRI data-driven analysis was conducted to identify changes in the intrinsic functional connectivity across the whole brain that were associated with the OMT. Spearman's correlations were used to test for the association between changes in intrinsic connectivity and individual reports of pain perception.

RESULTS

Compared to the Sham group, participants who received OMT showed significant alterations in the functional connectivity of several regions belonging to the pain matrix. Specifically, OMT was associated with decreased connectivity of a parietal cluster that includes the somatosensory cortex and an increase of connectivity of the right anterior insula and ventral and dorsal anterolateral prefrontal areas. Crucially, the change in connectivity strength observed in the ventral anterolateral prefrontal cortex, a putative region of the affective-reappraisive layer of the pain matrix, correlates with the reduction in pain perception caused by the OMT.

CONCLUSIONS

This study offers insights into the brain mechanisms underlying the analgesic effect of OMT. Our findings support a link between OMT-driven functional cortical architecture alterations and improved clinical outcomes.

Influences of heart rate feedback and autistic traits on affective mindreading

Although mindreading is an important prerequisite for successful social interactions, the underlying mechanisms are still matter of debate. It is unclear, for example, if inferring others' and own mental states are distinct processes or are based on a common mechanism. Using an affect-induction experimental set-up with an acoustic heart rate feedback that addresses affective mindreading in self and others, we investigated if non-autistic study participants relied on similar information for self- and other-directed mindreading. We assumed that due to altered mindreading capacities in autism, mainly individuals with low autistic traits would focus on additional sensory cues, such as heart rate, to infer their own and their gambling partner's affective states. Our analyses showed that the interpretation of a heart rate signal differed in self- and other-directed mindreading trials. This effect was modulated by autistic traits suggesting that individuals with higher autistic traits might not have interpreted the heart rate feedback for gambling partner ratings and differentiated less between self- and other-directed mindreading trials. We discuss these results in the context of a common mechanism underlying self- and other-directed mindreading and hypothesize that the weighting of internal and external sensory information might contribute to how we make sense of our and others' mental states.

The role of interoceptive awareness in shaping the relationship between desire thinking and cigarette consumption

Interoception, the ability to sense and interpret bodily sensations, has recently emerged as a crucial factor in substance use disorders, including smoking. However, the role of interoceptive awareness in tobacco use remains poorly understood. The relationship between interoceptive ability and addictive behavior is complex, and attempting to conceptualize it as a linear association is unlikely to fully capture the complexity of the mechanisms underlying cravings and urges. We hypothesized that the role played by interoceptive awareness in tobacco use is deeply linked to desire thinking, that is, the conscious and voluntary cognitive process orienting to prefigure images, information, and memories about positive target-related experiences. Desire thinking is typically observed in addiction, where it may contribute to interpreting specific bodily sensations, such as the perceived need for a cigarette. From this perspective, the physiological impact and inclination toward desire thinking contribute to a higher daily cigarette consumption, particularly in situations of low interoceptive awareness. To test this hypothesis, we assessed the physiological activation, the tendency toward desire thinking about smoking, cigarette consumption, and the interoceptive abilities of smoking volunteers. Through a moderation analysis, we showed that desire thinking about smoking predicts a higher number of cigarettes per day in individuals with lower interoceptive awareness (p < .05). These findings suggest that the relationship between desire thinking and interoceptive awareness is a fundamental component of tobacco use, highlighting the importance of taking into account the bodily feedback deriving from the cognitive representation of smoking in addiction research and therapy.

Mapping the emotional homunculus with fMRI

Emotions are commonly associated with bodily sensations, e.g., boiling with anger when overwhelmed with rage. Studies have shown that emotions are related to specific body parts, suggesting that somatotopically organized cortical regions that commonly respond to somatosensory and motor experiences might be involved in the generation of emotions. We used functional magnetic resonance imaging to investigate whether the subjective feelings of emotion are accompanied by the activation of somatotopically defined sensorimotor brain regions, thus aiming to reconstruct an "emotional homunculus." By defining the convergence of the brain activation patterns evoked by self-generated emotions during scanning onto a sensorimotor map created on participants' tactile and motor brain activity, we showed that all the evoked emotions activated parts of this sensorimotor map, yet with considerable overlap among different emotions. Although we could not find a highly specific segmentation of discrete emotions over sensorimotor regions, our results support an embodied experience of emotions.

General and anxiety-linked influences of acute serotonin reuptake inhibition on neural responses associated with attended visceral sensation

Ordinary sensations from inside the body are important causes and consequences of our affective states and behaviour, yet the roles of neurotransmitters in interoceptive processing have been unclear. With a within-subjects design, this experiment tested the impacts of acute increases of endogenous extracellular serotonin on the neural processing of attended internal sensations and the links of these effects to anxiety using a selective serotonin reuptake inhibitor (SSRI) (20 mg CITALOPRAM) and a PLACEBO. Twenty-one healthy volunteers (fourteen female, mean age 23.9) completed the Visceral Interoceptive Attention (VIA) task while undergoing functional magnetic resonance imaging (fMRI) with each treatment. The VIA task required focused attention on the heart, stomach, or visual sensation. The relative neural interoceptive responses to heart sensation [heart minus visual attention] (heart-IR) and stomach sensation [stomach minus visual attention] (stomach-IR) were compared between treatments. Visual attention subtraction controlled for the general effects of CITALOPRAM on sensory processing. CITALOPRAM was associated with lower interoceptive processing in viscerosensory (the stomach-IR of bilateral posterior insular cortex) and integrative/affective (the stomach-IR and heart-IR of bilateral amygdala) components of interoceptive neural pathways. In anterior insular cortex, CITALOPRAM reductions of heart-IR depended on anxiety levels, removing a previously known association between anxiety and the region's response to attended heart sensation observed with PLACEBO. Preliminary post hoc analysis indicated that CITALOPRAM effects on the stomach-IR of the amygdalae corresponded to acute anxiety changes. This direct evidence of general and anxiety-linked serotonergic influence on neural interoceptive processes advances our understanding of interoception, its regulation, and anxiety.

Aberrant Cardiac Interoception in Psychosis

BACKGROUND AND HYPOTHESIS

There is mounting evidence that cardiac interoception, the perception of one's heartbeat, is central to affective experiences. It has been proposed that symptoms of psychosis could arise from interoceptive dysfunction. Here we hypothesized that people with psychotic disorders would have a specific impairment in cardiac interoception, over and above broader perceptual deficits.

STUDY DESIGN

43 adults with a history of psychosis (31 schizophrenia, 12 schizoaffective disorder) and 41 matched control participants completed a heart rate discrimination task. Participants responded to whether they perceived a sequence of auditory tones to be faster or slower than their heart rate. By trialing a range of auditory tone rates, we estimated a threshold for each participant, the difference between perceived heart rate and actual heart rate. To test whether differences were specific to interoception, participants completed an exteroceptive control condition, testing their discrimination of the rate of 2 sets of audible sounds instead of heart rate.

STUDY RESULTS

Participants with a history of psychosis had greater absolute differences between perceived and actual heart rate, indicating over- or under-estimation of heart rate compared to healthy controls. This difference was specific to the interoceptive condition, and not explained by group differences in exteroceptive perception.

CONCLUSIONS

Psychotic disorders are associated with misestimation of heart rate. Further research may elucidate whether interoceptive abnormalities contribute to specific symptoms such as somatic delusions or affective features, and whether interoception could be a treatment target in psychotic disorders.

The influence of false interoceptive feedback on emotional state and balance responses to height-induced postural threat

Postural threat elicits a robust emotional response (e.g., fear and anxiety about falling), with concomitant modifications in balance. Recent theoretical accounts propose that emotional responses to postural threats are manifested, in part, from the conscious monitoring and appraisal of bodily signals ('interoception'). Here, we empirically probe the role of interoception in shaping emotional responses to a postural threat by experimentally manipulating interoceptive cardiac feedback. Sixty young adults completed a single 60-s trial under the following conditions: Ground (no threat) without heart rate (HR) feedback, followed by Threat (standing on the edge of a raised surface), during which participants received either false heart rate feedback (either slow [n = 20] or fast [n = 20] HR feedback) or no feedback (n = 20). Participants provided with false fast HR feedback during postural threat felt more fearful, reported feeling less stable, and rated the task more difficult than participants who did not receive HR feedback, or those who received false slow HR feedback (Cohen's d effect size = 0.79 - 1.78). However, behavioural responses did not significantly differ across the three groups. When compared to the no HR feedback group, false slow HR feedback did not significantly affect emotional or behavioural responses to the postural threat. These observations provide the first experimental evidence for emerging theoretical accounts describing the role of interoception in the generation of emotional responses to postural threats.

Vague sensations. About the background and consequences of discordance between actual and perceived physiological changes

Empirical evidence consistently shows that discordance, also called dissociation or discrepancy, between actual physiological (mainly visceral) events and their perceived counterparts is substantial. On the one hand, we typically do not perceive actual visceral events occurring in our bodies; on the other hand, sometimes we do perceive bodily changes that do not really take place. This narrative review presents the available empirical findings on the discordance, and summarizes possible explanations that approach the phenomenon from the viewpoint of evolution, cognitive development, and predictive processing. Also, the role of top-down factors, such as expectations and experiences is discussed. Finally, practically relevant consequences of the discordance are presented using the examples of mind-body practices, the placebo and nocebo phenomenon, and medically unexplained symptoms. It is concluded that the discordance between actual and perceived body changes can have a negative impact on health, mainly through issues with adherence and other behavioral factors. The existence of actual-perceived discordance should be taught and demonstrated in the elementary and high school, as well as in many areas of higher education.

From synaptic dysfunction to atypical emotional processing in autism

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition mainly characterized by social impairments and repetitive behaviors. Among these core symptoms, a notable aspect of ASD is the presence of emotional complexities, including high rates of anxiety disorders. The inherent heterogeneity of ASD poses a unique challenge in understanding its etiological origins, yet the utilization of diverse animal models replicating ASD traits has enabled researchers to dissect the intricate relationship between autism and atypical emotional processing. In this review, we delve into the general findings about the neural circuits underpinning one of the most extensively researched and evolutionarily conserved emotional states: fear and anxiety. Additionally, we explore how distinct ASD animal models exhibit various anxiety phenotypes, making them a crucial tool for dissecting ASD's multifaceted nature. Overall, to a proper display of fear response, it is crucial to properly process and integrate sensorial and visceral cues to the fear-induced stimuli. ASD individuals exhibit altered sensory processing, possibly contributing to the emergence of atypical phobias, a prevailing anxiety disorder manifested in this population. Moreover, these individuals display distinctive alterations in a pivotal fear and anxiety processing hub, the amygdala. By examining the neurobiological mechanisms underlying fear and anxiety regulation, we can gain insights into the factors contributing to the distinctive emotional profile observed in individuals with ASD. Such insights hold the potential to pave the way for more targeted interventions and therapies that address the emotional challenges faced by individuals within the autism spectrum.

Embodied language of emotions: Predicting human intuitions with linguistic distributions in blind and sighted individuals

Recent constructionist theories have suggested that language and sensory experience play a crucial role not only in how individuals categorise emotions but also in how they experience and shape them, helping to acquire abstract concepts that are used to make sense of bodily perceptions associated with specific emotions. Here, we aimed to investigate the role of sensory experience in conceptualising bodily felt emotions by asking 126 Italian blind participants to freely recall in which part of the body they commonly feel specific emotions (N = 15). Participants varied concerning visual experience in terms of blindness onset (i.e., congenital vs late) and degree of visual experience (i.e., total vs partial sensory loss). Using an Italian semantic model to estimate to what extent discrete emotions are associated with body parts in language experience, we found that all participants' reports correlated with the model predictions. Interestingly, blind - and especially congenitally blind - participants' responses were more strongly correlated with the model, suggesting that language might be one of the possible compensative mechanisms for the lack of visual feedback in constructing bodily felt emotions. Our findings present theoretical implications for the study of emotions, as well as potential real-world applications for blind individuals, by revealing, on the one hand, that vision plays an essential role in the construction of felt emotions and the way we talk about our related bodily (emotional) experiences. On the other hand, evidence that blind individuals rely more strongly on linguistic cues suggests that vision is a strong cue to acquire emotional information from the surrounding world, influencing how we experience emotions. While our findings do not suggest that blind individuals experience emotions in an atypical and dysfunctional way, they nonetheless support the view that promoting the use of non-visual emotional signs and body language since early on might help the blind child to develop a good emotional awareness as well as good emotion regulation abilities.

Influence of biased feedback on performance in a Vernier discrimination task

The influence of feedback on performance is a topic of ongoing debate, with some previous studies finding it to be ineffective, while others have discovered that it can be helpful or harmful. One possible reason for these inconsistent results may be that feedback can create a conflict between a person's beliefs and the sensory information they receive. In the present study, we used a Vernier discrimination task to examine the influence of biased feedback on performance, as this type of feedback is most likely to create conflict. Biased feedback refers to feedback that does not align with the subjects' choices. The Vernier discrimination task is a type of psychophysical task that is often used to measure an individual's ability to perceive differences in the position or orientation of two visual stimuli. The task involves presenting two stimuli, one of which is slightly offset from the other, and asking the individual to determine the direction and magnitude of the offset. In Experiment 1, feedback was provided after each trial using large-offset verniers as guidance. The large-offset verniers always received correct feedback, but the small and medium-offset verniers might receive biased feedback. In Experiment 2, feedback was provided after each block of eight verniers. In Experiment 3, we removed the large offset vernier to investigate the influence of block feedback on the signal and noise. The results showed that the accuracy for the target vernier decreased due to biased feedback in both the trial feedback (Experiment 1) and the block feedback (Experiment 2). However, in Experiments 1 and 2, performance improved when feedback was absent. Moreover, if the difference between the two types of stimuli is great, the individual will engage in encoding learning rather than decision learning (Experiments 1 and 2). If the discrimination between the two types of stimuli is low, an individual's ability to discriminate noise is more vulnerable to the influence of biased feedback than the ability to discriminate the signal (Experiment 3). These results are discussed in relation to the mechanism of biased feedback, the process of encoding learning, the monitoring of internal feedback, and the generalization of false decisions.

Cardiac and Gastric Interoceptive Awareness Have Distinct Neural Substrates

Interoceptive awareness, an awareness of the internal body state, guides adaptive behavior by providing ongoing information on body signals, such as heart rate and energy status. However, it is still unclear how interoceptive awareness of different body organs are represented in the human brain. Hence, we directly compared the neural activations accompanying attention to cardiac (related to heartbeat) and gastric (related to stomach) sensations, which generate cardiac and gastric interoceptive awareness, in the same population (healthy humans, N = 31). Participants were asked to direct their attention toward heart and stomach sensations and become aware of them in a magnetic resonance imaging (MRI) scanner. The results indicated that the neural activations underlying gastric attention encompassed larger brain regions, including the occipitotemporal visual cortices, bilateral primary motor cortices, primary somatosensory cortex, left orbitofrontal cortex, and hippocampal regions. Cardiac attention, however, selectively activated the right anterior insula extending to the frontal operculum compared with gastric attention. Moreover, our detailed analyses focusing on the insula, the most relevant region for interoceptive awareness, revealed that the left dorsal middle insula encoded cardiac and gastric attention via different activation patterns, but the posterior insula did not. Our results demonstrate that cardiac and gastric attention evoke different brain activation patterns; in particular, the selective activation may reflect differences in the functional roles of cardiac and gastric interoceptive awareness.

The Constructionist Approach to Emotional Aging: Theoretical Insights and Predictions

In this article, we introduce a constructionist approach to understanding emotional aging in adulthood. The purpose of the paper is to show how constructionism offers a promising avenue for gaining new insights into age-related changes in emotional experiences. We begin by introducing the constructionist theoretical framework and illustrating how constructionism may shape conceptualizations of emotional aging in adulthood. We compare the constructionist conceptualization of emotional aging with existing conceptualizations of emotional aging derived from prominent theories of emotional aging, focusing on how such conceptualizations highlight different aspects of emotional aging (e.g., different mechanisms) and overlook or downplay other aspects. We conclude by explicating what constructionism may offer research on emotional aging, including considerations of research agendas, study designs, and method of measurement.

Actions of a Shaken Heart: Interoception Interacts with Action Processing

In the present study, we investigated the modulatory influence of the unconscious, bodily arousal on motor-related embodied information. Specifically, we examined how the interoceptive prediction error interacts with the event-related potentials linked to action-effect processing. Participants were asked to perform a task with self-initiated or externally-triggered sounds while receiving synchronous or false auditory cardiac feedback. The results found that interaction of interoceptive manipulation and action-effect processing modulates the frontal subcomponent of the P3 response. During the synchronous cardiac feedback, the P3 response to self-initiated tones was enhanced. During the false cardiac feedback, the frontal cortical response was reversed. N1 and P2 components were affected by the interoceptive manipulation, but not by the interaction of interoception and action processing. These findings provide experimental support for the theoretical accounts of the interaction between interoception and action processing within a framework of predictive coding, manifested particularly in the higher stages of action processing.

Is There a Causal Link between the Left Lateralization of Language and Other Brain Asymmetries? A Review of Data Gathered in Patients with Focal Brain Lesions

This review evaluated if the hypothesis of a causal link between the left lateralization of language and other brain asymmetries could be supported by a careful review of data gathered in patients with unilateral brain lesions. In a short introduction a distinction was made between brain activities that could: (a) benefit from the shaping influences of language (such as the capacity to solve non-verbal cognitive tasks and the increased levels of consciousness and of intentionality); (b) be incompatible with the properties and the shaping activities of language (e.g., the relations between language and the automatic orienting of visual-spatial attention or between cognition and emotion) and (c) be more represented on the right hemisphere due to competition for cortical space. The correspondence between predictions based on the theoretical impact of language on other brain functions and data obtained in patients with lesions of the right and left hemisphere was then assessed. The reviewed data suggest that different kinds of hemispheric asymmetries observed in patients with unilateral brain lesions could be subsumed by common mechanisms, more or less directly linked to the left lateralization of language.

The effect of haptic stimulation simulating heartbeats on the regulation of physiological responses and prosocial behavior under stress: The influence of interoceptive accuracy

Research has discovered the modulatory effect of peripheral stimulation simulating altered bodily signals on emotion. Whether such an effect varies depending on one's interoceptive accuracy (IAc) remains unclear. Therefore, we provided haptic stimulation simulating participants' slowed-down heartbeats or no stimulation while they engaged in socially stressful tasks to examine whether participants reacted differently depending on their IAc. Results showed that haptic stimulation exhibited the opposite effect on participants with different levels of IAc for both heart rate and heart rate variability (HRV). When receiving the stimulation, participants with higher IAc showed less increased heart rate and more elevated HF than participants with lower IAc. In contrast, in the absence of stimulation, an opposite pattern of response depending on participants' IAc was observed. The modulatory effect of stimuli and IAc on prosocial behavior was not significant. Individual differences in IAc were shown to affect how one perceives/responds to altered bodily signals.

An active inference perspective on the negative symptoms of schizophrenia

Predictive coding has played a transformative role in the study of psychosis, casting delusions and hallucinations as statistical inference in a system with abnormal precision. However, the negative symptoms of schizophrenia, such as affective blunting, avolition, and asociality, remain poorly understood. We propose a computational framework for emotional expression based on active inference-namely that affective behaviours such as smiling are driven by predictions about the social consequences of smiling. Similarly to how delusions and hallucinations can be explained by predictive uncertainty in sensory circuits, negative symptoms naturally arise from uncertainty in social prediction circuits. This perspective draws on computational principles to explain blunted facial expressiveness and apathy-anhedonia in schizophrenia. Its phenomenological consequences also shed light on the content of paranoid delusions and indistinctness of self-other boundaries. Close links are highlighted between social prediction, facial affect mirroring, and the fledgling study of interoception. Advances in automated analysis of facial expressions and acoustic speech patterns will allow empirical testing of these computational models of the negative symptoms of schizophrenia.

The Difficult Integration between Human and Animal Studies on Emotional Lateralization: A Perspective Article

Even if for many years hemispheric asymmetries have been considered as a uniquely human feature, an increasing number of studies have described hemispheric asymmetries for various behavioral functions in several nonhuman species. An aspect of animal lateralization that has attracted particular attention has concerned the hemispheric asymmetries for emotions, but human and animal studies on this subject have been developed as independent lines of investigation, without attempts for their integration. In this perspective article, after an illustration of factors that have hampered the integration between human and animal studies on emotional lateralization, I will pass to analyze components and stages of the processing of emotions to distinguish those which point to a continuum between humans and many animal species, from those which suggest a similarity only between humans and great apes. The right lateralization of sympathetic functions (involved in brain and bodily activities necessary in emergency situations) seems consistent across many animal species, whereas asymmetries in emotional communication and in structures involved in emotional experience, similar to those observed in humans, have been documented only in primates.

Vocal signals only impact speakers' own emotions when they are self-attributed

Emotions are often accompanied by vocalizations whose acoustic features provide information about the physiological state of the speaker. Here, we ask if perceiving these affective signals in one's own voice has an impact on one's own emotional state, and if it is necessary to identify these signals as self-originated for the emotional effect to occur. Participants had to deliberate out loud about how they would feel in various familiar emotional scenarios, while we covertly manipulated their voices in order to make them sound happy or sad. Perceiving the artificial affective signals in their own voice altered participants' judgements about how they would feel in these situations. Crucially, this effect disappeared when participants detected the vocal manipulation, either explicitly or implicitly. The original valence of the scenarios also modulated the vocal feedback effect. These results highlight the role of the exteroception of self-attributed affective signals in the emergence of emotional feelings.

Shared Characteristics of Intrinsic Connectivity Networks Underlying Interoceptive Awareness and Empathy

Awareness of internal bodily sensations (interoceptive awareness; IA) and its connection to complex socioemotional abilities like empathy has been postulated, yet the functional neural circuitry they share remains poorly understood. The present fMRI study employs independent component analysis (ICA) to investigate which empathy facet (Cognitive or Affective) shares resting-state functional connectivity (rsFC) and/or BOLD variability (rsBOLD) with IA. Healthy participants viewed an abstract nonsocial movie demonstrated to evoke strong rsFC in brain networks resembling rest (InScapes), and resultant rsFC and rsBOLD data were correlated with self-reported empathy and IA questionnaires. We demonstrate a bidirectional behavioral and neurobiological relationship between empathy and IA, depending on the type of empathy interrogated: Affective empathy and IA share both rsFC and rsBOLD, while Cognitive empathy and IA only share rsBOLD. Specifically, increased rsFC in the right inferior frontal operculum (rIFO) of a larger attention network was associated with increased vicarious experience but decreased awareness of inner body sensations. Furthermore, increased rsBOLD between brain regions of an interoceptive network was related to increased sensitivity to internal sensations along with decreased Affective empathy. Finally, increased rsBOLD between brain regions subserving a mentalizing network related to not only an improved ability to take someone's perspective, but also a better sense of mind-body interconnectedness. Overall, these findings suggest that the awareness of one's own internal body changes (IA) is related to the socioemotional ability of feeling and understanding another's emotional state (empathy) and critically, that this relationship is reflected in the brain's resting state neuroarchitecture. Methodologically, this work highlights the importance of utilizing rsBOLD as a complementary window alongside rsFC to better understand neurological phenomena. Our results may be beneficial in aiding diagnosis in clinical populations such as autism spectrum disorder (ASD), where participants may be unable to complete tasks or questionnaires due to the severity of their symptoms.

Skipping a Beat: Heartbeat-Evoked Potentials Reflect Predictions during Interoceptive-Exteroceptive Integration

Several theories propose that emotions and self-awareness arise from the integration of internal and external signals and their respective precision-weighted expectations. Supporting these mechanisms, research indicates that the brain uses temporal cues from cardiac signals to predict auditory stimuli and that these predictions and their prediction errors can be observed in the scalp heartbeat-evoked potential (HEP). We investigated the effect of precision modulations on these cross-modal predictive mechanisms, via attention and interoceptive ability. We presented auditory sequences at short (perceived synchronous) or long (perceived asynchronous) cardio-audio delays, with half of the trials including an omission. Participants attended to the cardio-audio synchronicity of the tones (internal attention) or the auditory stimuli alone (external attention). Comparing HEPs during omissions allowed for the observation of pure predictive signals, without contaminating auditory input. We observed an early effect of cardio-audio delay, reflecting a difference in heartbeat-driven expectations. We also observed a larger positivity to the omissions of sounds perceived as synchronous than to the omissions of sounds perceived as asynchronous when attending internally only, consistent with the role of attentional precision for enhancing predictions. These results provide support for attentionally modulated cross-modal predictive coding and suggest a potential tool for investigating its role in emotion and self-awareness.

The insula, a grey matter of tastes: a volumetric MRI study in dementia with Lewy bodies

Background

Despite the growing number of discoveries during the past decades about its functions, the insula remains a mysterious ‘island’. In addition to its involvement in basic functions such as gustation and interoception, the insular cortex is now considered a key region for integrated functions such as emotion/motivation processing, decision-making and self-consciousness. We hypothesized that this structure, standing at the crossroads of such functions, could ground personal tastes in general, beyond food preferences and aesthetic judgements. Given that dementia with Lewy bodies is characterized by a focal atrophy within the insular cortex from the early stages, this condition provides an opportunity to test such a hypothesis.

Methods

We developed a questionnaire to assess potential changes in personal tastes, submitted it to a cohort of 23 patients with early-stage dementia with Lewy bodies and compared their questionnaire results to those of 20 age-matched healthy controls. Furthermore, we performed a global and regional neuroimaging study to test for a potential correlation between the patients’ scores for changes in personal tastes and their insular cortex volumes.

Results

Our results indicate that the patients presented significant changes in personal tastes compared to the controls, in both food and non-food domains. Moreover, imaging analyses confirmed the involvement of the insular cortex atrophy in the changes in personal tastes using global analysis, and in both food and non-food domains using regional analysis.

Conclusions

These results bring new insights into the role of the insula as a ‘grey matter of tastes’, this structure supporting personal preferences in general, beyond the food domain. The insular cortex could be involved through its role in motivational processes by the representation of subjective awareness of bodily states during the phenomenological experience of stimulus appraisal. However, we also argue that it could support the abstract representations of personal tastes as self-concepts, acutely exemplifying embodied cognition. Finally, the questionnaire on changes in tastes could constitute an interesting tool to help early diagnosis of dementia with Lewy bodies and to assess insular dysfunction more generally.

An interoceptive illusion of effort induced by false heart-rate feedback

Interoception, or the sense of the internal state of the body, is key to the adaptive regulation of our physiological needs. Recent theories contextualize interception within a predictive coding framework, according to which the brain both estimates and controls homeostatic and physiological variables, such as hunger, thirst, and effort levels, by orchestrating sensory, proprioceptive, and interoceptive signals from inside the body. This framework suggests that providing false interoceptive feedback may induce misperceptions of physiological variables, or "interoceptive illusions." Here we ask whether it is possible to produce an illusory perception of effort by giving participants false acoustic feedback about their heart-rate frequency during an effortful cycling task. We found that participants reported higher levels of perceived effort when their heart-rate feedback was faster compared with when they cycled at the same level of intensity with a veridical feedback. However, participants did not report lower effort when their heart-rate feedback was slower, which is reassuring, given that failing to notice one's own effort is dangerous in ecologically valid conditions. Our results demonstrate that false cardiac feedback can produce interoceptive illusions. Furthermore, our results pave the way for novel experimental manipulations that use illusions to study interoceptive processing.

The Central Autonomic Network and Regulation of Bladder Function

The autonomic nervous system (ANS) is involved in the regulation of physiologic and homeostatic parameters relating particularly to the visceral organs and the co-ordination of physiological responses to threat. Blood pressure and heart rate, respiration, pupillomotor reactivity, sexual function, gastrointestinal secretions and motility, and urine storage and micturition are all under a degree of ANS control. Furthermore, there is close integration between the ANS and other neural functions such as emotion and cognition, and thus brain regions that are known to be important for autonomic control are also implicated in emotional functions. In this review we explore the role of the central ANS in the control of the bladder, and the implications of this for bladder dysfunction in diseases of the ANS.

A historical review of investigations on laterality of emotions in the human brain

Different models of emotional lateralization, advanced since the first clinical observations raised this issue, will be reviewed following their historical progression. The clinical investigations that have suggested a general dominance of the right hemisphere for all kinds of emotions and the experimental studies that have proposed a different hemispheric specialization for positive vs. negative emotions (valence hypothesis) or for approach vs. withdrawal tendencies (motivational hypothesis) will be reviewed first and extensively. This historical review will be followed by a short discussion of recent anatomo-clinical and activation studies that have investigated (a) emotional and behavioral disorders of patients with asymmetrical forms of fronto-temporal degeneration and (b) laterality effects in specific brain structures (amygdala, ventro-medial prefrontal cortex, and anterior insula) playing a critical role in different components of emotions. Overall, these studies support the hypothesis of a right hemisphere dominance for all components of the emotional system.

Emotions and the Right Hemisphere: Can New Data Clarify Old Models?

Models advanced to explain hemispheric asymmetries in representation of emotions will be discussed following their historical progression. First, the clinical observations that have suggested a general dominance of the right hemisphere for all kinds of emotions will be reviewed. Then the experimental investigations that have led to proposal of a different hemispheric specialization for positive versus negative emotions (valence hypothesis) or, alternatively, for approach versus avoidance tendencies (motivational hypothesis) will be surveyed. The discussion of these general models will be followed by a review of recent studies which have documented laterality effects within specific brain structures, known to play a critical role in different components of emotions, namely the amygdata in the computation of emotionally laden stimuli, the ventromedial prefrontal cortex in the integration between cognition and emotion and in the control of impulsive reactions and the anterior insula in the conscious experience of emotion. Results of these recent investigations support and provide an updated integrated version of early models assuming a general right hemisphere dominance for all kinds of emotions.

The neurobiology of interoception in health and disease

Interoception is the sensing of internal bodily sensations. Interoception is an umbrella term that encompasses (1) the afferent (body-to-brain) signaling through distinct neural and humoral (including immune and endocrine) channels; (2) the neural encoding, representation, and integration of this information concerning internal bodily state; (3) the influence of such information on other perceptions, cognitions, and behaviors; (4) and the psychological expression of these representations as consciously accessible physical sensations and feelings. Interoceptive mechanisms ensure physiological health through the cerebral coordination of homeostatic reflexes and allostatic responses that include motivational behaviors and associated affective and emotional feelings. Furthermore, the conscious, unitary sense of self in time and space may be grounded in the primacy and lifelong continuity of interoception. Body-to-brain interactions influence physical and mental well-being. Consequently, we show that systematic investigation of how individual differences, and within-individual changes, in interoceptive processing can contribute to the mechanistic understanding of physical and psychological disorders. We present a neurobiological overview of interoception and describe how interoceptive impairments at different levels relate to specific physical and mental health conditions, including sickness behaviors and fatigue, depression, eating disorders, autism, and anxiety. We frame these findings in an interoceptive predictive processing framework and highlight potential new avenues for treatments.

Error-related cardiac response as information for visibility judgements

Interoception provides information about the saliency of external or internal sensory events and thus may inform perceptual decision-making. Error in performance is an example of a motivationally significant internal event that evokes autonomic nervous system response resembling the orienting response: heart rate deceleration, increased skin conductance response, and pupil dilation. Here, we investigate whether error-related cardiac activity may serve as a source of information when making metacognitive judgments in an orientation discrimination backward masking task. In the first experiment, we found that the heart accelerates less after an incorrect stimuli discrimination than after a correct one. Moreover, this difference becomes more pronounced with increasing subjective visibility of the stimuli. In the second experiment, this accuracy-dependent pattern of cardiac activity was found only when participants listened to their own heartbeats, but not someone else's. We propose that decision accuracy coded in cardiac activity may be fed as a cue to subjective visibility judgments.

Central neural substrates involved in temperature discrimination, thermal pain, thermal comfort, and thermoregulatory behavior

A phylogenetically novel pathway that emerged with primate encephalization is described, which conveys high-fidelity cutaneous thermosensory activity in "labeled lines" to a somatotopic map in the dorsal posterior insular cortex. It originates in lamina I of the superficial dorsal horn and ascends by way of the lateral spinothalamic tract and a distinct region in posterolateral thalamus. It evolved from the homeostatic sensory activity that represents the physiologic (interoceptive) condition of the body and drives the central autonomic network, which underlies all affective feelings from the body. Accordingly, human discriminative thermal sensations are accompanied by thermally motivated behaviors and thermal feelings of comfort or discomfort (unless neutral), which evidence suggests are associated with activity in the insular, cingulate, and orbitofrontal cortices, respectively. Yet, the substrates for thermoregulatory behavior have not been established, and several strong candidates (including the hypothalamus and the bed nucleus of the stria terminalis) are discussed. Finally, the neural underpinnings for relationships between thermal affect and social feelings (warm-positive/cold-negative) are addressed, including the association of hyperthermia with clinical depression.

Breathlessness and the body: Neuroimaging clues for the inferential leap

Breathlessness debilitates millions of people with chronic illness. Mismatch between breathlessness severity and objective disease markers is common and poorly understood. Traditionally, sensory perception was conceptualised as a stimulus-response relationship, although this cannot explain how conditioned symptoms may occur in the absence of physiological signals from the lungs or airways. A Bayesian model is now proposed, in which the brain generates sensations based on expectations learnt from past experiences (priors), which are then checked against incoming afferent signals. In this model, psychological factors may act as moderators. They may alter priors, change the relative attention towards incoming sensory information, or alter comparisons between priors and sensations, leading to more variable interpretation of an equivalent afferent input. In the present study we conducted a supplementary analysis of previously published data (Hayen et al., 2017). We hypothesised that individual differences in psychological traits (anxiety, depression, anxiety sensitivity) would correlate with the variability of subjective perceptions of equivalent breathlessness challenges. To better understand the resulting inferential leap in the brain, we explored where these behavioural measures correlated with functional brain activity across subjects. Behaviourally, anxiety sensitivity was found to positively correlate with each subject's variability of intensity and unpleasantness during mild breathlessness, and with variability of unpleasantness during strong breathlessness. In the brain, anxiety sensitivity was found to negatively correlate with precuneus activity during anticipation, positively correlate with anterior insula activity during mild breathlessness, and negatively correlate with parietal sensorimotor areas during strong breathlessness. Our findings suggest that anxiety sensitivity may reduce the robustness of this Bayesian sensory perception system, increasing the variability of breathlessness perception and possibly susceptibility to symptom misinterpretation. These preliminary findings in healthy individuals demonstrate how differences in psychological function influence the way we experience bodily sensations, which might direct us towards better understanding of symptom mismatch in clinical populations.

Physiological and psychological correlates of attention-related body sensations (tingling and warmth)

Body sensations play an essential role in the subjective evaluation of our physical health, illness, and healing. They are impacted by peripheral somatic and external processes, but they are also heavily modulated by mental processes, e.g., attention, motor control, and emotion. Body sensations, such as tingling, numbness, pulse, and warmth, can emerge due to simply focusing attention on a body part. It is however an open question, if these sensations are connected with actual peripheral changes or happen “only in the mind.” Here, we first tested whether the intensity of such attention-related body sensations is related to autonomic and somatomotor physiological processes and to psychological traits. In this study, attention-related body sensations were not significantly connected to changes in physiology, except warmth sensation, which was linked to decrease in muscle tension. Overall intensity of tingling significantly correlated with body awareness and tendentiously with body–mind practice. This strengthened the hypothesis that attention-related body sensations are more the result of top–down functions, and the connection with peripheral processes is weak. Here, we suggested a novel protocol to examine the effect of manipulating attention on body sensations, which together with our results and discussion can inspire future researches.

The Insula Mediates Access to Awareness of Visual Stimuli Presented Synchronously to the Heartbeat

The processing of interoceptive signals in the insular cortex is thought to underlie self-awareness. However, the influence of interoception on visual awareness and the role of the insular cortex in this process remain unclear. Here, we show in a series of experiments that the relative timing of visual stimuli with respect to the heartbeat modulates visual awareness. We used two masking techniques and show that conscious access for visual stimuli synchronous to participants' heartbeat is suppressed compared with the same stimuli presented asynchronously to their heartbeat. Two independent brain imaging experiments using high-resolution fMRI revealed that the insular cortex was sensitive to both visible and invisible cardio-visual stimulation, showing reduced activation for visual stimuli presented synchronously to the heartbeat. Our results show that interoceptive insular processing affects visual awareness, demonstrating the role of the insula in integrating interoceptive and exteroceptive signals and in the processing of conscious signals beyond self-awareness.

SIGNIFICANCE STATEMENT

There is growing evidence that interoceptive signals conveying information regarding the internal state of the body influence perception and self-awareness. The insular cortex, which receives sensory inputs from both interoceptive and exteroceptive sources, is thought to integrate these multimodal signals. This study shows that cardiac interoceptive signals modulate awareness for visual stimuli such that visual stimuli occurring at the cardiac frequency take longer to access visual awareness and are more difficult to discriminate. Two fMRI experiments show that the insular region is sensitive to this cardio-visual synchrony even when the visual stimuli are rendered invisible through interocular masking. The results indicate a perceptual and neural suppression for visual events coinciding with cardiac interoceptive signals.

The calming effect of a new wearable device during the anticipation of public speech

We assessed the calming effect of doppel, a wearable device that delivers heartbeat-like tactile stimulation on the wrist. We tested whether the use of doppel would have a calming effect on physiological arousal and subjective reports of state anxiety during the anticipation of public speech, a validated experimental task that is known to induce anxiety. Two groups of participants were tested in a single-blind design. Both groups wore the device on their wrist during the anticipation of public speech, and were given the cover story that the device was measuring blood pressure. For only one group, the device was turned on and delivered a slow heartbeat-like vibration. Participants in the doppel active condition displayed lower increases in skin conductance responses relative to baseline and reported lower anxiety levels compared to the control group. Therefore, the presence, as opposed to its absence, of a slow rhythm, which in the present study was instantiated as an auxiliary slow heartbeat delivered through doppel, had a significant calming effect on physiological arousal and subjective experience during a socially stressful situation. This finding is discussed in relation to past research on responses and entrainment to rhythms, and their effects on arousal and mood.

Allostatic Self-efficacy: A Metacognitive Theory of Dyshomeostasis-Induced Fatigue and Depression

This paper outlines a hierarchical Bayesian framework for interoception, homeostatic/allostatic control, and meta-cognition that connects fatigue and depression to the experience of chronic dyshomeostasis. Specifically, viewing interoception as the inversion of a generative model of viscerosensory inputs allows for a formal definition of dyshomeostasis (as chronically enhanced surprise about bodily signals, or, equivalently, low evidence for the brain's model of bodily states) and allostasis (as a change in prior beliefs or predictions which define setpoints for homeostatic reflex arcs). Critically, we propose that the performance of interoceptive-allostatic circuitry is monitored by a metacognitive layer that updates beliefs about the brain's capacity to successfully regulate bodily states (allostatic self-efficacy). In this framework, fatigue and depression can be understood as sequential responses to the interoceptive experience of dyshomeostasis and the ensuing metacognitive diagnosis of low allostatic self-efficacy. While fatigue might represent an early response with adaptive value (cf. sickness behavior), the experience of chronic dyshomeostasis may trigger a generalized belief of low self-efficacy and lack of control (cf. learned helplessness), resulting in depression. This perspective implies alternative pathophysiological mechanisms that are reflected by differential abnormalities in the effective connectivity of circuits for interoception and allostasis. We discuss suitably extended models of effective connectivity that could distinguish these connectivity patterns in individual patients and may help inform differential diagnosis of fatigue and depression in the future.

Bodily Contributions to Emotion: Schachter’s Legacy for a Psychological Constructionist View on Emotion

Although early emotion theorists posited that bodily changes contribute to emotion, the primary view in affective science over the last century has been that emotions produce bodily changes. Recent findings from physiology, neuroscience, and neuropsychology support the early intuition that body representations can help constitute emotion. These findings are consistent with the modern psychological constructionist hypothesis that emotions emerge when representations of bodily changes are conceptualized as an instance of emotion. We begin by introducing the psychological constructionist approach to emotion. With Schachter as inspiration, we next examine how embodied representations contribute to affective states, and ultimately emotion, with inflammation as a key example. We close by looking forward to future research on how body representations contribute to human experience.

Active interoceptive inference and the emotional brain

We review a recent shift in conceptions of interoception and its relationship to hierarchical inference in the brain. The notion of interoceptive inference means that bodily states are regulated by autonomic reflexes that are enslaved by descending predictions from deep generative models of our internal and external milieu. This re-conceptualization illuminates several issues in cognitive and clinical neuroscience with implications for experiences of selfhood and emotion. We first contextualize interoception in terms of active (Bayesian) inference in the brain, highlighting its enactivist (embodied) aspects. We then consider the key role of uncertainty or precision and how this might translate into neuromodulation. We next examine the implications for understanding the functional anatomy of the emotional brain, surveying recent observations on agranular cortex. Finally, we turn to theoretical issues, namely, the role of interoception in shaping a sense of embodied self and feelings. We will draw links between physiological homoeostasis and allostasis, early cybernetic ideas of predictive control and hierarchical generative models in predictive processing. The explanatory scope of interoceptive inference ranges from explanations for autism and depression, through to consciousness. We offer a brief survey of these exciting developments.

This article is part of the themed issue ‘Interoception beyond homeostasis: affect, cognition and mental health’.

Tinnitus- related distress: evidence from fMRI of an emotional stroop task

Background

Chronic tinnitus affects 5 % of the population, 17 % suffer under the condition. This distress seems mainly to be dependent on negative cognitive-emotional evaluation of the tinnitus and selective attention to the tinnitus. A well-established paradigm to examine selective attention and emotional processing is the Emotional Stroop Task (EST). Recent models of tinnitus distress propose limbic, frontal and parietal regions to be more active in highly distressed tinnitus patients. Only a few studies have compared high and low distressed tinnitus patients. Thus, this study aimed to explore neural correlates of tinnitus-related distress.

Methods

Highly distressed tinnitus patients (HDT, n = 16), low distressed tinnitus patients (LDT, n = 16) and healthy controls (HC, n = 16) underwent functional magnetic resonance imaging (fMRI) during an EST, that used tinnitus-related words and neutral words as stimuli. A random effects analysis of the fMRI data was conducted on the basis of the general linear model. Furthermore correlational analyses between the blood oxygen level dependent response and tinnitus distress, loudness, depression, anxiety, vocabulary and hypersensitivity to sound were performed.

Results

Contradictory to the hypothesis, highly distressed patients showed no Stroop effect in their reaction times. As hypothesized HDT and LDT differed in the activation of the right insula and the orbitofrontal cortex. There were no hypothesized differences between HDT and HC. Activation of the orbitofrontal cortex and the right insula were found to correlate with tinnitus distress.

Conclusions

The results are partially supported by earlier resting-state studies and corroborate the role of the insula and the orbitofrontal cortex in tinnitus distress.

Neural correlates of somatoform disorders from a meta-analytic perspective on neuroimaging studies

Somatoform disorders (SD) are common medical disorders with prevalence rates between 3.5% and 18.4%, depending on country and medical setting. SD as outlined in the ICD-10 exhibits various biological, social, and psychological pathogenic factors. Little is known about the neural correlates of SD. The aims of this meta-analysis are to identify neuronal areas that are involved in SD and consistently differ between patients and healthy controls. We conducted a systematic literature research on neuroimaging studies of SD. Ten out of 686 studies fulfilled the inclusion criteria and were analyzed using activation likelihood estimation. Five neuronal areas differ between patients with SD and healthy controls namely the premotor and supplementary motor cortexes, the middle frontal gyrus, the anterior cingulate cortex, the insula, and the posterior cingulate cortex. These areas seem to have a particular importance for the occurrence of SD. Out of the ten studies two did not contribute to any of the clusters. Our results seem to largely overlap with the circuit network model of somatosensory amplification for SD. It is conceivable that functional disorders, independent of the clinical impression, show similar neurobiological processes. While overlaps do occur it is necessary to understand single functional somatic syndromes and their aetiology for future research, terminology, and treatment guidelines.

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Five neurobiological areas correlate with the occurrence of somatoform disorders (SD).

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Areas are crucial for emotional, evaluative and cognitive aspects of pain processing.

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Prefrontal areas indicate involvement of pain memory in SD.

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Functional disorders might have central sensitization as an underlying factor.

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Results do not support the classification of SD as medically unexplained symptoms.

Loss aversion is associated with bilateral insula volume. A voxel based morphometry study

Loss aversion is a decision bias, reflecting a greater sensitivity to losses than to gains in a decision situation. Recent neuroscientific research has shown that mesocorticolimbic structures like ventromedial prefrontal cortex and the ventral striatum constitute a bidirectional neural system that processes gains and losses and exhibits a neural basis of loss aversion. On a functional and structural level, the amygdala and insula also seem to play an important role in the processing of loss averse behavior. By applying voxel-based morphometry to structural brain images in N=41 healthy participants, the current study provides further evidence for the relationship of brain structure and loss aversion. The results show a negative correlation of gray matter volume in bilateral posterior insula as well as left medial frontal gyrus with individual loss aversion. Hence, higher loss aversion is associated with lower gray matter volume in these brain areas. Both structures have been discussed to play important roles in the brain's salience network, where the posterior insula is involved in interoception and the detection of salience. The medial frontal gyrus might impact decision making through its dense connections with the anterior cingulate cortex. A possible explanation for the present finding is that structural differences in these regions alter the processing of losses and salience, possibly biasing decision making towards avoidance of negative outcomes.

Conditioned respiratory threat in the subdivisions of the human periaqueductal gray

The sensation of breathlessness is the most threatening symptom of respiratory disease. The different subdivisions of the midbrain periaqueductal gray (PAG) are intricately (and differentially) involved in integrating behavioural responses to threat in animals, while the PAG has previously only been considered as a single entity in human research. Here we investigate how these individual PAG columns are differently involved with respiratory threat. Eighteen healthy subjects were conditioned to associate shapes with certain or uncertain impending respiratory load, and scanned the following day during anticipation and application of inspiratory loading using 7 T functional MRI. We showed activity in the ventrolateral PAG (vlPAG) during anticipation of resistive loading, with activity in the lateral PAG (lPAG) during resistive loading, revealing spatially and temporally distinct functions within this structure. We propose that lPAG is involved with sensorimotor responses to breathlessness, while the vlPAG operates within the threat perception network for impending breathlessness.

DOI:http://dx.doi.org/10.7554/eLife.12047.001

Many people find feeling breathless one of the most upsetting symptoms of respiratory diseases, and breathlessness often causes anxiety that makes the condition seem more threatening than it is. Studies in animals suggest that a small cluster of neurons called the periaqueductal gray is important for responding to threats. This cluster, located at the top of the brainstem, is divided into parallel columns running from top to bottom. In animals, these columns are known to have distinct roles, but human research has tended to consider the periaqueductal gray as a single, uniform entity.

Faull et al. wanted to find out whether different columns of the human periaqueductal gray have distinct roles in the perception of respiratory threat. During the study, participants breathed through a tube while watching shapes appear on a screen. This tube could be altered to make breathing more or less difficult – much like breathing through a narrow drinking straw.

A conditioning session was first conducted so that participants learned that certain shapes on the screen signalled that their breathing was about to become difficult, while other shapes signalled normal breathing. A second session was then conducted in a brain scanner, using a technique called functional magnetic resonance imaging. This allowed Faull et al. to compare brain activity during the anticipation of difficult breathing with the brain activity during the breathing challenge itself.

The results show that the column at the front of the periaqueductal gray (the ventrolateral column) was more active when participants saw the shape that signaled upcoming breathing difficulty. In contrast, difficult breathing was associated with activity in the lateral column (at the side of the periaqueductal gray).

Thus, the different columns of the human periaqueductal gray have different roles in the response to respiratory threat. Future studies could investigate how these columns interact with each other and with other brain regions. Such understanding is important for a range of conditions that may be influenced by the activity of the periaqueductal gray, including disruptions in bladder control, hypertension, chronic pain, and asthma.

DOI:http://dx.doi.org/10.7554/eLife.12047.002

Emotional Intelligence Partially Mediates the Association between Anxiety Sensitivity and Anxiety Symptoms1,2

Anxiety Sensitivity (AS), the propensity to fear the somatic, mental, and social consequences of anxiety, is associated with an elevated risk of developing anxiety disorders. It was hypothesized that Emotional Intelligence (EI) might serve as a mediating variable between AS and anxiety symptom expression. Sixty-one healthy adults (30 men, 31 women; M age = 30.4 yr., SD = 8.0), recruited through posted advertisements, completed the Anxiety Sensitivity Index (ASI) and the ANX subscale of the Personality Assessment Inventory (PAI), as well as three assessments of EI, including two indices of the Ability model of EI (MSCEIT; SREIS), and one index of the Trait model of EI (i.e., Bar-On EQ-i). Partial mediation between AS and ANX was found for the EQ-i but not for the MSCEIT or SREIS, as determined by the bootstrap method of mediation analysis. The association between AS and anxiety symptoms was partly explained through its effects on the intervening variable of Trait EI, and points to the possibility that interventions improving Trait EI may be useful in reducing the expression of anxiety symptoms in people with high AS.