Closing the gap between the inside and the outside: interoceptive sensitivity and social distances

Heart Rate Variability as a Potential Predictor of Response to Intranasal Esketamine in Patients with Treatment-Resistant Depression: A Preliminary Report

Background: Esketamine has received approval as a nasal spray (ESK-NS) for treatment-resistant depression (TRD) and evidence from real-world investigations has confirmed the effectiveness of ESK-NS, albeit with interindividual differences in response. Heart rate variability (HRV), defined as the fluctuation in time interval between consecutive heartbeats, can be used to measure autonomic dysfunction in psychiatric disorders and its role has been investigated in diagnosis and prognosis of depression. Methods: This preliminary report aims to evaluate HRV parameters and their association with treatment outcome in 18 patients (55.6% males, 55.6 ± 9.39 years old) with TRD treated with a target dose of ESK-NS for one month (mean dose: 80.9 ± 9.05 mg). The Beck Depression Inventory (BDI) and a 3 min resting electrocardiogram were used to assess changes in depressive symptoms and HRV measurements before and after treatment. Results: Responders (n = 8, 44.5%; based on ≥30% BDI scores reduction) displayed lower HRV values than non-responders at baseline (p = 0.019), which increased at one month (p = 0.038). Receiver-Operating Characteristic (ROC) curves obtained from a logistic regression displayed a discriminative potential for baseline HRV in our sample (AUC = 0.844). Conclusions: These preliminary observations suggest a mutual interaction between esketamine and HRV, especially in relation to treatment response. Further studies are required to investigate electrophysiological profiles among predictors of response to ESK-NS and allow for personalized intervention strategies in TRD that still represent a public health concern.

Electrocardiographic activity depends on the relative position between intimate persons

Interpersonal space (IPS) refers to the area surrounding the body in which we engage in social interactions while maintaining our comfort. Numerous previous studies have reported the psychological and physiological changes associated with the proximity of two people engaged in face-to-face interaction. Currently, there is limited knowledge about how the relative position between two socially intimate individuals affects their psychological and physiological states. This research measured the subjective discomfort and electrocardiographic responses of participants when standing static at various relative positions. The highest discomfort, lowest heart rate, and highest heart rate variability (HRV; parasympathetic activity index) were observed when the friend stood in the face-to-face position. Interestingly, heart rate also decreased when the friend stood on the right side, although HRV did not change. We interpreted the results as suggesting that the presence of a familiar person elicits the electrocardiographic responses associated with an increase in parasympathetic activity.

The thermoception task: a thermal imaging-based procedure for measuring awareness of changes in peripheral body temperature

Although thermal body signals provide crucial information about the state of an organism and changes in body temperature may be a sign of affective states (e.g., stress, pain, sexual arousal), research on thermal awareness is limited. Here we developed a task measuring awareness of changes in peripheral body temperature (thermal interoception) and compared it to the classical heartbeat counting task (cardiac interoception). With an infrared light bulb we delivered stimuli of different temperature intensities to the right hand of 31 healthy participants. Thermal interoceptive accuracy, i.e., the difference between participants' real and perceived change in hand temperature, showed good interindividual variability. We found that thermal interoception did not correlate with (and was generally higher than) cardiac interoception, suggesting that different interceptive channels provide separate contributions to awareness of bodily states. Moreover, the results hint at the great salience of thermal signals and the need for thermoregulation in day-to-day life. Finally, thermal interoceptive accuracy was associated with self-reported awareness of body temperature changes and with the ability to regulate distress by focusing on body sensations. Our task has the potential to significantly increase current knowledge about the role of interoception in cognition and behavior, particularly in social and emotional contexts.NEW & NOTEWORTHY We developed a novel task measuring awareness of changes in peripheral body temperature (i.e., thermal interoception). To avoid tactile confounds present in existing thermoceptive tasks, we used an infrared light bulb to deliver stimuli of different temperature intensities to the hand of participants and asked them to judge the perceived change in their hand temperature. Performance in the task showed good interindividual variability, did not correlate with cardiac interoceptive tasks, and was associated with self-reported thermosensitivity.

Room to breathe: Using adaptive architecture to examine the relationship between alexithymia and interoception

OBJECTIVE

Individuals with alexithymia experience difficulties interpreting emotional states in self and others, which has been associated with interoceptive impairment. Current theories are primarily based on subjective and conscious measures of interoceptive sensitivity, such as heartrate detection, but it is unclear whether similar observations would be found for objective or implicit psychophysiological measures. The present exploratory study assesses the potential of a novel assay through the use of adaptive immersive architecture [ExoBuilding].

METHODS

N = 88 participants were screened for alexithymic traits and N = 27 individuals, representing the range of scores, were sampled to participate in the behavioural task. In a repeated-measures design, participants were placed within ExoBuilding and asked to match their respiration to its movement. Performance was compared to a two-dimensional pacer condition. Behavioural (accuracy) and psychophysiological (Respiratory Sinus Arrhythmia [RSA] and heartrate) measures were compared across conditions, and also related to individual alexithymic traits.

RESULTS

Participants with higher levels of alexithymia performed less accurately than participants with lower levels, in both conditions. High-alexithymia participants showed a smaller reduction in heartrate over the course of the ExoBuilding condition than low-alexithymia participants, although there were no differences in RSA between conditions or participants.

CONCLUSION

Alexithymia extends beyond conscious interoceptive activities and is also observed in immersive contexts that usually exert psychophysiological effects on typical occupants. These initial findings highlight the importance of considering both conscious and implicit measures of interoception, and we suggest ways in which theories of alexithymia might benefit from capturing this distinction.

Looking within: Interoceptive sensibility in young adults with psychotic-like experiences

AIM

Interoception is the ability to sense internal bodily changes and research indicates that it may play a role in the development of mental illness. In recent years, preliminary evidence has shown that interoception is impaired in people with psychosis. Interoceptive sensibility, a meta-cognitive aspect of interoception, has never been studied across the psychosis continuum. The present study aimed at assessing interoceptive sensibility in youth with psychotic-like experiences.

METHOD

We invited a sample of young adults (N = 609; age 19-21 years) to complete an online survey that included a measure of interoceptive sensibility (the Multidimensional Assessment of Interoceptive Awareness-2) and the Community Assessment of Psychotic Experiences-Positive Scale -15 (CAPE-P15). Using the recommended cutoff for the CAPE-P15, the overall sample was divided into two groups (high/low risk for psychosis).

RESULTS

Significant group differences were observed in several dimensions of interoceptive sensibility. A logistic regression analysis indicated that scores in the subscales of Not-Distracting, Not-Worrying, Attention-Regulation, Emotional Awareness, Body Listening, and Trusting significantly predicted increased risk for psychosis.

CONCLUSION

Abnormal interoceptive sensibility may be a vulnerability marker for psychosis. These results, however, await further validation from additional comprehensive, longitudinal studies. Enhanced interoceptive sensibility has been reported following contemplative training, thus creating opportunities for future interventions to delay or prevent psychotic illness.

Heart rate variability and interoceptive accuracy predict impaired decision-making in Gambling Disorder

BACKGROUND AND AIMS

Gambling Disorder (GD) entails maladaptive patterns of decision-making. Neurophysiological research points out the effect of parasympathetic arousal, including phasic changes in heart rate variability (HRV), and interoceptive accuracy (IA, i.e., the ability to track changes in bodily signals), on decision-making. Nevertheless, scarce evidence is available on their role in GD. This is the first study exploring the impact in GD of respiratory sinus arrhythmia (RSA), an index of HRV, and IA on decision-making, as measured by the Iowa Gambling Task (IGT).

METHODS

Twenty-two patients experiencing problems with slot-machines or video lottery terminals gambling and 22 gender- and age-matched healthy controls (HC) were recruited. A resting ECG was performed before and after the completion of the IGT. IA was assessed throughout the heartbeat detection task. We conducted a MANCOVA to detect the presence of significant differences between groups in RSA reactivity and IA. A linear regression model was adopted to test the effect of factors of interest on IGT scores.

RESULTS

Patients with GD displayed significantly decreased RSA reactivity (P = 0.002) and IA (P = 0.024) compared to HCs, even after controlling for affective symptoms, age, smoking status, and BMI. According to the linear regression model, cardiac vagal reactivity and IA significantly predict decision-making impairments on the IGT (P = 0.008; P = 0.019).

DISCUSSION AND CONCLUSIONS

Although the exact pathways linking HRV and IA to impaired decision-making in GD remain to be identified, a broader exploration relying upon an embodiment-informed framework may contribute to shed further light on the clinical phenomenology of the disorder.

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.

A School Intervention Helps Decrease Daily Stress While Enhancing Social Integration in Children

Stress coping is highly relevant during childhood. This study analyses how the participation in a behavioral intervention involving mindfulness-based practices and empathic collaboration activities impact on diurnal cortisol rhythm and social integration in children. In both experimental and waitlist groups, we evaluated before and after the intervention: daily stress, by sampling salivary cortisol at three measurement time-points, and social integration, assessed by a social preference index. Daily average cortisol (DAC) and the area under the curve (AUC) differed when comparing pre-post intervention values in both groups: in the experimental group these measures decreased while in the waitlist group DAC and AUC increased. At the end of the intervention, the experimental group showed an enhancement in the social preference index whereas this parameter diminished in the waitlist group. This kind of behavioral intervention seems to be effective at reducing daily stress and improving social integration in Primary School children.

Interoception and Emotion: A Potential Mechanism for Intervention With Manual Treatment

Interoception is considered a perception pathway as important as the exteroceptive pathways for determining responses to maintain homeostasis. There is evidence about the influence of the interoception on emotional responses as these expressions are considered to be a combination of physical, environmental and individual beliefs. A large percentage of afferent fibers in the body are related to free nerve endings which, when stimulated, reach the insular cortex that participates in the process of emotions. The viscera afferent fibers represent 5% to 15% of all these inputs. Evidence emerges that demonstrates the importance of visceral health as part of the treatment of patients with emotional imbalances. It can be postulated that manual treatment applied to visceral fasciae can assist in interoceptive balance and have a positive impact on emotions. Therefore, the objective of the present study is to discuss the concepts of interoception, central sensitization, emotional health and visceral manual treatment.

The Peripersonal Space in a social world

The PeriPersonal Space (PPS) has been defined as the space surrounding the body, where physical interactions with elements of the environment take place. As our world is social in nature, recent evidence revealed the complex modulation of social factors onto PPS representation. In light of the growing interest in the field, in this review we take a close look at the experimental approaches undertaken to assess the impact of social factors onto PPS representation. Our social world also influences the personal space (PS), a concept stemming from social psychology, defined as the space we keep between us and others to avoid discomfort. Here we analytically compare PPS and PS with the aim of understanding if and how they relate to each other. At the behavioral level, the multiplicity of experimental methodologies, whether well-established or novel, lead to somewhat divergent results and interpretations. Beyond behavior, we review physiological and neural signatures of PPS representation to discuss how interoceptive signals could contribute to PPS representation, as well as how these internal signals could shape the neural responses of PPS representation. In particular, by merging exteroceptive information from the environment and internal signals that come from the body, PPS may promote an integrated representation of the self, as distinct from the environment and the others. We put forward that integrating internal and external signals in the brain for perception of proximal environmental stimuli may also provide us with a better understanding of the processes at play during social interactions. Adopting such an integrative stance may offer novel insights about PPS representation in a social world. Finally, we discuss possible links between PPS research and social cognition, a link that may contribute to the understanding of intentions and feelings of others around us and promote appropriate social interactions.

Listen to Your Heart-Ecological Momentary Assessment of Interoceptive Accuracy, Awareness and Sensibility: A Pilot Study

Background: Interoception is a multi-facetted phenomenon including interoceptive accuracy, awareness and sensibility. Deficits in interoception have been associated with psychological distress. However, little is known about the course of interoception over time. The present study aimed at examining interoception in an ecological momentary assessment (EMA)-setting. Methods: A seven-day smartphone-based EMA was conducted in a community sample of sixty-one participants (age: M = 24.1, SD = 7.00, n = 54 female (88.5%)). To control for potential practice effects of repeated assessments during the EMA phase, participants were randomly assigned to a control (n = 30) and an interoception (n = 31) group. The latter was assessed for interoceptive accuracy, awareness and sensibility. Before and after the EMA phase, all participants were assessed for interoception in the laboratory. Results: Multilevel analyses revealed significant fluctuations for all three interoceptive facets, around 50% of variance was due to within-person variability. There were only practice effects for the subscale "Attention Regulation", measuring interoceptive sensibility. Conclusion: The facets of interoception can be assessed in an EMA-setting. Repeated interoceptive assessments do not necessarily lead to an improvement of participants' interoceptive abilities. It could be shown that all interoceptive facets fluctuate, which should be considered in future research.

A Practice-Inspired Mindset for Researching the Psychophysiological and Medical Health Effects of Recreational Dance (Dance Sport)

“Dance” has been associated with many psychophysiological and medical health effects. However, varying definitions of what constitute “dance” have led to a rather heterogenous body of evidence about such potential effects, leaving the picture piecemeal at best. It remains unclear what exact parameters may be driving positive effects. We believe that this heterogeneity of evidence is partly due to a lack of a clear definition of dance for such empirical purposes. A differentiation is needed between (a) the effects on the individual when the activity of “dancing” is enjoyed as a dancer within different dance domains (e.g., professional/”high-art” type of dance, erotic dance, religious dance, club dancing, Dance Movement Therapy (DMT), and what is commonly known as hobby, recreational or social dance), and (b) the effects on the individual within these different domains, as a dancer of the different dance styles (solo dance, partnering dance, group dance; and all the different styles within these). Another separate category of dance engagement is, not as a dancer, but as a spectator of all of the above. “Watching dance” as part of an audience has its own set of psychophysiological and neurocognitive effects on the individual, and depends on the context where dance is witnessed. With the help of dance professionals, we first outline some different dance domains and dance styles, and outline aspects that differentiate them, and that may, therefore, cause differential empirical findings when compared regardless (e.g., amount of interpersonal contact, physical exertion, context, cognitive demand, type of movements, complexity of technique and ratio of choreography/improvisation). Then, we outline commonalities between all dance styles. We identify six basic components that are part of any dance practice, as part of a continuum, and review and discuss available research for each of them concerning the possible health and wellbeing effects of each of these components, and how they may relate to the psychophysiological and health effects that are reported for “dancing”: (1) rhythm and music, (2) sociality, (3) technique and fitness, (4) connection and connectedness (self-intimation), (5) flow and mindfulness, (6) aesthetic emotions and imagination. Future research efforts might take into account the important differences between types of dance activities, as well as the six components, for a more targeted assessment of how “dancing” affects the human body.

Close facial emotions enhance physiological responses and facilitate perceptual discrimination

Accumulating evidence indicates that the peripersonal space (PPS) constitutes a privileged area for efficient processing of proximal stimuli, allowing to flexibly adapt our behavior both to the physical and social environment. Whether and how behavioral and physiological signatures of PPS relate to each other in emotional contexts remains, though, elusive. Here, we addressed this question by having participants to discriminate male from female faces depicting different emotions (happiness, anger or neutral) and presented at different distances (50 cm-300 cm) while we measured the reaction time and accuracy of their responses, as well as pupillary diameter, heart rate and heart rate variability. Results showed facilitation of participants' performances (i.e., faster response time) when faces were presented close compared to far from the participants, even when controlling for retinal size across distances. These behavioral effects were accompanied by significant modulation of participants' physiological indexes when faces were presented in PPS. Interestingly, both PPS representation and physiological signals were affected by features of the seen faces such as the emotional valence, its sex and the participants' sex, revealing the profound impact of social context onto the autonomic state and behavior within PPS. Together, these findings suggest that both external and internal signals contribute in shaping PPS representation.

The physiological correlates of interpersonal space

Interpersonal space (IPS) is the area around the body that individuals maintain between themselves and others during social interactions. When others violate our IPS, feeling of discomfort rise up, urging us to move farther away and reinstate an appropriate interpersonal distance. Previous studies showed that when individuals are exposed to closeness of an unknown person (a confederate), the skin conductance response (SCR) increases. However, if the SCR is modulated according to participant’s preferred IPS is still an open question. To test this hypothesis, we recorded the SCR in healthy participants when a confederate stood in front of them at various distances simulating either an approach or withdrawal movement (Experiment 1). Then, the comfort-distance task was adopted to measure IPS: participants stop the confederate, who moved either toward or away from them, when they felt comfortable with other’s proximity (Experiment 2). We found higher SCR when the confederate stood closer to participants simulating an IPS intrusion, compared to when the confederate moved farther away. Crucially, we provide the first evidence that SCR, acting as a warning signal, contributes to interpersonal distance preference suggesting a functional link between behavioral components of IPS regulation and the underlying physiological processes.

Interoceptive Awareness Is Negatively Related to the Exteroceptive Manipulation of Bodily Self-Location

The perception of being located within one's body (i.e., bodily self-location) is an essential feature of everyday self-experience. However, by manipulating exteroceptive input, healthy participants can easily be induced to perceive themselves as being spatially dislocated from their physical bodies. It has previously been suggested that interoception, i.e., the processing of inner physiological signals, contributes to the stability of body representations; however, this relationship has not previously been tested for different dimensions of interoception and bodily self-location. In the present study, using an advanced automatized setup, we systematically manipulated participants' perspective of their own body (first- vs third-person perspective) as well as the synchrony of visuotactile stimulation (synchronous vs asynchronous). The malleability of bodily self-location was assessed using a questionnaire targeting in-body and out-of-body experiences. Participants also performed a heartbeat discrimination task to assess their interoceptive accuracy (behavioral performance), interoceptive sensibility (confidence in their interoceptive abilities), and interoceptive awareness (meta-cognitive representation of interoceptive signals). Bodily self-location was significantly influenced by perspective, with third-person perspective being associated with stronger out-of-body experiences compared to first-person perspective. Furthermore, there was a significant perspective × stimulation interaction, with subsequent analyses showing that participants reported out-of-body experiences particularly under third-person perspective combined with synchronous visuotactile stimulation. Correlation and regression analyses revealed that meta-cognitive interoceptive awareness was specifically and negatively related to the exteroceptively mediated malleability of body experiences. These results indicate that the perception of the self being located within one's body relies on the interaction of exteroceptive input and higher-order interoceptive abilities. This has implications for theoretical considerations about the bodily self in health as well as for the understanding of disturbed bodily self-processing in clinical contexts.

Recovery, Interrupted: The Zeigarnik Effect in EMDR Therapy and the Adaptive Information Processing Model

This theoretical article proposes that the Zeigarnik effect (ZE) (i.e., better memory for interrupted rather than completed tasks) explains the formation of traumatic memories as incomplete tasks. These tasks are thought to foster pathological rumination toward their completion while simultaneously stoking avoidance. After looking at the role of the ZE in the development and maintenance of posttraumatic stress disorder (PTSD), the article examines the physiological substrates of the ZE, including brain network imbalance, excessive autonomic nervous system activation, and prospective memory acuity for incomplete events. Eye movement desensitization and reprocessing (EMDR) therapy is proposed as uniquely capable of providing closure to interrupted facets of traumatic recollection, as this treatment may facilitate greater memory reconsolidation and inhibition of Zeigarnik reminders than extinction-based models. The ZE may be implicated in the overall EMDR treatment effect, as it is activated in several EMDR phases. Specifically, the use of brief interrupted exposures during EMDR reprocessing may benefit from the ZE in resolving traumatic events. Eye movements themselves are also considered interruptions to rumination upon traumatic memory. Recommendations for the further use of the ZE are described, and suggestions are made for future research. Protocol modifications and interweaves which mobilize the preceding insights are also provided.

Interoceptive accuracy moderates the response to a glucose load: a test of the predictive coding framework

Recently, interoception and homeostasis have been described in terms of predictive coding and active inference. Afferent signals update prior predictions about the state of the body, and stimulate the autonomic mediation of homeostasis. Performance on tests of interoceptive accuracy (IAc) may indicate an individual's ability to assign precision to interoceptive signals, thus determining the relative influence of ascending signals and the descending prior predictions. Accordingly, individuals with high IAc should be better able to regulate during the postprandial period. One hundred females were allocated to consume glucose, an artificially sweetened drink, water or no drink. Before, and 30 min after a drink, IAc, heart rate (HR) and blood glucose (BG) were measured, and participants rated their hunger, thirst and mood. A higher IAc was related to lower BG levels, a decline in anxiety and a higher HR, after consuming glucose. A higher IAc also resulted in a larger decline in hunger if they consumed either glucose or sucralose. These data support the role of active inference in interoception and homeostasis, and suggest that the ability to attend to interoceptive signals may be critical to the maintenance of physical and emotional health.

The body comes first. Embodied reparation and the co-creation of infant bodily-self

During infancy relational experiences of body-to-body exchanges (i.e., embodied interactions) contribute to the infant's bodily perception. Early embodied interactions are based on countless multimodal reciprocal exchanges, in which mother and infant contribute to interpersonal rhythmic cycles of co-regulation (i.e., attunement). However, it remains unclear how infants and their mothers actually accomplish attunement in their exchanges. Interactions between mothers and their infants typically fluctuate between attuned and misattuned states and recovery attunement states by a process called 'reparation'. Here, we discuss recent neuroscientific evidence that provides insight into the mechanisms underpinning the concepts of attunement and misattunement in early embodied interactions. We propose that a process of embodied reparation might be achieved within the dyad through tactile contact behaviors (e.g., skin-to-skin, affectionate touch) and maternal interoceptive sensitivity (i.e., ability to perceive internal input about the state of one's own body). We describe how these elements that mothers provide during embodied interactions with their infants, might contribute not only to bodily attunement, but also to co-create the infant bodily-self.

Effect of manual approaches with osteopathic modality on brain correlates of interoception: an fMRI study

The present randomised placebo controlled trial explored the extent to which osteopathic manipulative treatment (OMT) affects brain activity, particularly the insula, during both an “interoceptive awareness” and “exteroceptive awareness” task in a sample of 32 right-handed adults with chronic Low Back Pain (CLBP) randomly assigned to either the OMT or sham group. Patients received 4 weekly sessions and fMRI was performed at enrolment (T0), immediately after the first session (T1) and at 1 month (T2). The results revealed that the OMT produced a distinct and specific reduction in BOLD response in specific brain areas related to interoception, i.e., bilateral insula, ACC, left striatum and rMFG. The observed trend across the three time points appears uncharacteristic. At T1, a marginal increase of the BOLD response was observed in all the above-mentioned areas except the rMFG, which showed a decrease in BOLD response. At T2, the response was the opposite: areas related to interoception (bilateral insula and ACC) as well as the rMFG and left striatum demonstrated significant decreased in BOLD response. The findings of this study provide an insight into the effects of manual therapies on brain activity and have implications for future research in the field.

Interoception and Social Connection

Interoception – the process of sensing bodily signals – has gained much interest in recent years, due to its role in physical and mental well-being. Here, we focus on the role of interoception in social connection, which is a relatively new and growing research area. Studies in this area suggest that interoception may help in appraising physiological signals in social situations, but also that (challenging) social situations may reduce interoceptive processing by shifting attention from internally- to externally- focused. We discuss potential mechanisms for the influence of interoception on social connection and highlight that flexibility in engaging interoception in social situations may be particularly important. We end with a discussion of loneliness – an extreme case of poor social connection, which is associated with physiological decline and increased mortality risk, and propose that interoceptive dysregulation is involved. We suggest that interventions aimed to improve interoceptive abilities, such as mindfulness-based meditation practices, may be key for alleviating loneliness and improving social connection.

Interoceptive accuracy and interoceptive sensibility in individuals with alcohol use disorder-Different phenomena with different clinical correlations?

BACKGROUND

Interoception may contribute to substance use disorder as it relates to the body's experience of substance use or withdrawal. However, only a few studies have directly investigated associations between interoception and alcohol use. The objective of this study was to compare individuals with alcohol use disorder (AUD) and healthy controls on interoceptive sensibility and accuracy.

METHODS

The sample was comprised of two groups: individuals meeting criteria for AUD (N = 114) and healthy controls (N = 110) not meeting criteria for AUD. Interoceptive sensibility was assessed with a self-report measure (the Private Body Consciousness subscale) and interoceptive accuracy - with a behavioral measure (the Schandry test). In addition, associations between interoception and other well-recognized correlates of AUD (sleep problems, depressive and anxiety symptoms, impulsivity) were tested. Barratt's Impulsiveness Scale, Brief Symptom Inventory, and Athens Insomnia Scale were utilized to assess psychopathological symptoms as covariates.

RESULTS

When controlling for level of anxiety, sleep problems, age, sex and education, individuals with AUD scored significantly higher on self-reported interoceptive sensibility and lower on interoceptive accuracy in comparison to healthy controls. Higher interoceptive sensibility was associated with more severe sleep problems and anxiety symptoms.

CONCLUSIONS

These results have to be treated as preliminary and need to be replicated; however, findings indicate that interoception may present a novel therapeutic target for treatment of AUD.

Enhanced audio-tactile multisensory interaction in a peripersonal task after echolocation

Peripersonal space (PPS) is created by a multisensory interaction between different sensory modalities and can be modified by experience. In this article, we investigated whether an auditory training, inside the peripersonal space area, can modify the PPS around the head in sighted participants. The auditory training was based on echolocation. We measured the participant's reaction times to a tactile stimulation on the neck, while task-irrelevant looming auditory stimuli were presented. Sounds more strongly affect tactile processing when located within a limited distance from the body. We measured spatially dependent audio-tactile interaction as a proxy of PPS representation before and after an echolocation training. We found a significant speeding effect on tactile RTs after echolocation, specifically when sounds where around the location where the echolocation task was performed. This effect could not be attributed to a task repetition effect nor to a shift of spatial attention, as no changes of PPS were found in two control groups of participants, who performed the PPS task after either a break or a temporal auditory task (with stimuli located at the same position of echolocation task). These findings show that echolocation affects multisensory processing inside PPS representation, likely to better represent the space where external stimuli, have to be localized.

Detecting peripersonal space: The promising role of ultrasonics

INTRODUCTION

The approach of an external stimulus to the peripersonal space (PPS) modifies some physiological measures, including the cerebral blood flow (CBF) in the supplementary motor area and premotor cortex. CBF measurement may be useful to assess brain activations when producing specific motor responses, likely mediated by cortical and subcortical neural circuits.

METHODS

This study investigated PPS in 15 healthy humans by characterizing the hemodynamic responses (pulsatility index, PI; and heart rate, HR) related to different directions of movements of individual's hand toward and backward his/her own face, so to perturb PPS).

RESULTS

We observed that the CBF and HR were enhanced more when the stimulated hand was inside the PPS of the face in the passive and active condition than when the hand was outside the PPS and during motor imagery task.

CONCLUSIONS

These results suggest that the modulation of PPS-related brain responses depends on specific sensory-motor integration processes related to the location and the final position of a target in the PPS. We may thus propose TCD as a rapid and easy approach to get information concerning brain responses related to stimuli approaching the PPS. Understanding the modulations of brain activations during tasks targeting PPS can help to understand the results of psychophysical and behavioral trials and to plan patient-tailored cognitive rehabilitative training.

Interoception and Its Interaction with Self, Other, and Emotion Processing: Implications for the Understanding of Psychosocial Deficits in Borderline Personality Disorder

PURPOSE OF REVIEW

We review evidence for the potential importance of interoception, i.e., the processing of signals arising from inside the body, for deficient psychosocial functioning in borderline personality disorder (BPD).

RECENT FINDINGS

Evidence suggests that variability in interoception interacts with higher-order psychological functions such as self, other, and emotion processing. These domains are characteristically impaired in BPD, suggesting a likely causal role of disturbed interoception in the etiology of the disorder. The inability to identify and describe one's own emotional states represents a proxy of impaired interoception which might further mediate between the perception of inner physiological conditions and psychosocial functioning in BPD. There is preliminary evidence explaining how early life stress might adversely affect central interoceptive representation and psychosocial functioning in BPD. Based on these findings and the specific pattern of disturbances in BPD, we propose the crucial role of interoception in an integrated biobehavioral model for BPD.

Interoception and Autonomic Correlates during Social Interactions. Implications for Anorexia

The aim of this study is to investigate the bodily-self in Restrictive Anorexia, focusing on two basic aspects related to the bodily self: autonomic strategies in social behavior, in which others' social desirability features, and social cues (e.g., gaze) are modulated, and interoception (i.e., the sensitivity to stimuli originating inside the body). Furthermore, since previous studies carried out on healthy individuals found that interoception seems to contribute to the autonomic regulation of social behavior, as measured by Respiratory Sinus Arrhythmia (RSA), we aimed to explore this link in anorexia patients, whose ability to perceive their bodily signal seems to be impaired. To this purpose, we compared a group of anorexia patients (ANg; restrictive type) with a group of Healthy Controls (HCg) for RSA responses during both a resting state and a social proxemics task, for their explicit judgments of comfort in social distances during a behavioral proxemics task, and for their Interoceptive Accuracy (IA). The results showed that ANg displayed significantly lower social disposition and a flattened autonomic reactivity during the proxemics task, irrespective of the presence of others' socially desirable features or social cues. Moreover, unlike HCg, the autonomic arousal of ANg did not guide behavioral judgments of social distances. Finally, IA was strictly related to social disposition in both groups, but with opposite trends in ANg. We conclude that autonomic imbalance and its altered relationship with interoception might have a crucial role in anorexia disturbances.

Primary Emotional Systems and Personality: An Evolutionary Perspective

The present article highlights important concepts of personality including stability issues from the perspective of situational demands and stability over the life-course. Following this more introductory section, we argue why individual differences in primary emotional systems may represent the phylogenetically oldest parts of human personality. Our argumentation leads to the need to increasingly consider individual differences in the raw affects/emotions of people to understand human personality in a bottom-up fashion, which can be coordinated with top-down perspectives. In support of this idea, we also review existing evidence linking individual differences in primal emotions as assessed with the Affective Neuroscience Personality Scales and the widely accepted Big Five Model of Personality. In this context, we provide additional evidence on the link between primal emotions and personality in German and Chinese sample populations. In short, this article addresses evolutionary perspectives in the evaluation of human personality, highlighting some of the ancestral emotional urges that probably still control variations in the construction of human personality structures. Moreover, we address how individual differences in primary emotional systems can illuminate linkages to major human psychopathologies and the potential advantages and disadvantages of carrying a certain personality trait within certain cultural/environmental niches.

The spatial self in schizophrenia and autism spectrum disorder

Schizophrenia (SZ) and autism spectrum disorder (ASD) have been both described as disorders of the self. However, the manner in which the sense of self is impacted in these disorders is strikingly different. In the current review, we propose that SZ and ASD lay at opposite extremes of a particular component of the representation of self; namely, self-location and the construct of peripersonal space. We evaluate emerging literature suggesting that while SZ individuals possess an extremely weak or variable bodily boundary between self and other, ASD patients possess a sharper self-other boundary. Furthermore, based on recent behavioral and neural network modeling findings, we propose that multisensory training focused on either sharpening (for SZ) or making shallower (for ASD) the self-other boundary may hold promise as an interventional tool in the treatment of these disorders.

Interactions Between Body and Social Awareness in Yoga

BACKGROUND/OBJECTIVE

Bodily processes have been intimately linked to social-cognitive and affective functions, such as compassion and empathy. Yet, little is known about how awareness of bodily processes influences social awareness and vice versa, especially in nonobservational but experiential investigations. This study investigated the relationship between psychometrically reported body and social awareness (including altruism, empathy, perspective-taking, and compassion) in 90 yoga and yoga-/mediation-naive control participants. In modern postural yoga, advanced practitioners claim both increased compassion and inner focus.

METHODS

Multiple regression analyses were conducted to predict (1) the level of yoga practice from body awareness and social awareness skills in the yoga group and (2) body awareness from social skills in both groups.

RESULTS

Body awareness and compassion were significant positive and independent predictors of yoga expertise. This finding supports practitioners' anecdotal claims but also implies that both functions tap into different aspects of yoga expertise. When body awareness was predicted, altruism emerged as a significant negative predictor in the yoga group (but not control group) as a function of yoga practice.

CONCLUSION

These results might compellingly suggest that, despite high compassion, heightened bodily self-awareness might increase a self-centred perspective and limit altruistic acts in advanced yoga practitioners.

'Bodily precision': a predictive coding account of individual differences in interoceptive accuracy

Individuals differ in their awareness of afferent information from within their bodies, which is typically assessed by a heartbeat perception measure of 'interoceptive accuracy' (IAcc). Neural and behavioural correlates of this trait have been investigated, but a theoretical explanation has yet to be presented. Building on recent models that describe interoception within the free energy/predictive coding framework, this paper applies similar principles to IAcc, proposing that individual differences in IAcc depend on 'precision' in interoceptive systems, i.e. the relative weight accorded to 'prior' representations and 'prediction errors' (that part of incoming interoceptive sensation not accounted for by priors), at various levels within the cortical hierarchy and between modalities. Attention has the effect of optimizing precision both within and between sensory modalities. Our central assumption is that people with high IAcc are able, with attention, to prioritize interoception over other sensory modalities and can thus adjust the relative precision of their interoceptive priors and prediction errors, where appropriate, given their personal history. This characterization explains key findings within the interoception literature; links results previously seen as unrelated or contradictory; and may have important implications for understanding cognitive, behavioural and psychopathological consequences of both high and low interoceptive awareness.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.

Interoception and Positive Symptoms in Schizophrenia

The present study focuses on the multifaceted concept of self-disturbance in schizophrenia, adding knowledge about a not yet investigated aspect, which is the interoceptive accuracy. Starting from the assumption that interoceptive accuracy requires an intact sense of self, which otherwise was proved to be altered in schizophrenia, the aim of the present study was to explore interoceptive accuracy in a group of schizophrenia patients, compared to healthy controls. Furthermore, the possible association between interoceptive accuracy and patients' positive and negative symptomatology was assessed. To pursue these goals, a group of 23 schizophrenia patients and a group of 23 healthy controls performed a heartbeat perception task. Patients' symptomatology was assessed by means of the Positive and Negative Syndrome Scale (PANSS). Results demonstrated significantly lower interoceptive accuracy in schizophrenia patients compared to healthy controls. This difference was not accounted for participants' age, BMI, anxiety levels, and heart rate. Furthermore, patients' illness severity, attention and pharmacological treatment did not influence their interoceptive accuracy levels. Interestingly, a strong positive relation between interoceptive accuracy and positive symptoms severity, especially Grandiosity, was found. The present results demonstrate for the first time that interoceptive accuracy is altered in schizophrenia. Furthermore, they prove a specific association between interoceptive accuracy and positive symptomatology, suggesting that the symptom Grandiosity might be protective against an altered basic sense of self in patients characterized by higher sensibility to their inner bodily sensations.

Multisensory simultaneity judgment and proximity to the body

The integration of information across different sensory modalities is known to be dependent upon the statistical characteristics of the stimuli to be combined. For example, the spatial and temporal proximity of stimuli are important determinants with stimuli that are close in space and time being more likely to be bound. These multisensory interactions occur not only for singular points in space/time, but over “windows” of space and time that likely relate to the ecological statistics of real-world stimuli. Relatedly, human psychophysical work has demonstrated that individuals are highly prone to judge multisensory stimuli as co-occurring over a wide range of time—a so-called simultaneity window (SW). Similarly, there exists a spatial representation of peripersonal space (PPS) surrounding the body in which stimuli related to the body and to external events occurring near the body are highly likely to be jointly processed. In the current study, we sought to examine the interaction between these temporal and spatial dimensions of multisensory representation by measuring the SW for audiovisual stimuli through proximal–distal space (i.e., PPS and extrapersonal space). Results demonstrate that the audiovisual SWs within PPS are larger than outside PPS. In addition, we suggest that this effect is likely due to an automatic and additional computation of these multisensory events in a body-centered reference frame. We discuss the current findings in terms of the spatiotemporal constraints of multisensory interactions and the implication of distinct reference frames on this process.

Sensitization and Interoception as Key Neurological Concepts in Osteopathy and Other Manual Medicines

Historically, approaches used in manual medicine to explain patient reported symptoms have been focused on the so-called exteroceptive paradigm. Arguably, this mindset lacks an appropriate "reading system" able to interpret musculoskeletal disorders from a different perspective, where the properties of the nervous system are embraced into a more holistic and functional-related context. Interestingly, if the underpinning mechanisms of a given treatment scenario/effect are taking into account, the majority of research outcomes focuses on a proprioceptive/exteroceptive explanation, leaving ting aside the additional or even central role of interoception. Currently, to date, the application of theoretical knowledge acquired on the relatively recent neuroscientific concepts and evidence concerning of interoception, sensitization, touch, autonomic functions, inflammation, and pain into a clinical/research manual medicine scenario is lacking, even if theoretically, the impact on the possible etiological mechanisms and treatment effects seems to be important. Here, we propose the conceptual foundations for a new way of interpreting and reading patients' clinical reported outcomes scenario based on interoception and sensitization. We argue that this will provide a foundation to create the ground for future research focusing on the hypotheses that manual therapies, specifically osteopathy, can intercede with sensitization states, at all levels, using interoceptive pathways.

The bodily self and its disorders: neurological, psychological and social aspects

PURPOSE OF REVIEW

The experience of ourselves as an embodied agent with a first-person perspective is referred to as 'bodily self'. We present a selective overview of relevant clinical and experimental studies.

RECENT FINDINGS

Sharing multisensory body space with others can be observed in patients with structurally altered bodies (amputations, congenital absence of limbs), with altered functionality after hemiplegia, such as denial of limb ownership (somatoparaphrenia) and with alterations in bodily self-consciousness on the level of the entire body (e.g. in autoscopic phenomena). In healthy participants, the mechanisms underpinning body ownership and observer perspective are empirically investigated by multisensory stimulation paradigms to alter the bodily self. The resulting illusions have promoted the understanding of complex disturbances of the bodily self, such as out-of-body experiences. We discuss the role of interoception in differentiating between self and others and review current advances in the study of body integrity identity disorder, a condition shaped as much by neurological as by social-psychological factors.

SUMMARY

We advocate a social neuroscience approach to the bodily self that takes into account the interactions between body, mind and society and might help close the divide between neurology and psychiatry.

When interoception helps to overcome negative feelings caused by social exclusion

Social exclusion affects mental and physical health. The ability to regulate emotional responses to social exclusion is therefore essential for our well-being. As individual differences in detecting bodily signals (interoceptive sensitivity, IS) have been associated with the ability of emotion regulation, we aimed at exploring whether IS fosters coping with social exclusion and flexibility in emotion regulation. The first study investigated subjective feelings and behavioral affiliation tendencies in response to ostracism using a cyberball paradigm. Sixty-nine participants were assessed who differed with respect to IS. The second study examined habitual emotion regulation processes focusing on suppression and reappraisal as well as IS in 116 participants. Main results were that the effect of ostracism on distress and behavioral affiliation tendencies were qualified by IS—being ostracized had less impact on participants with stronger IS. Furthermore, Study 2 revealed that IS was associated with habitually stronger emotion regulation strategies. We conclude that having access to bodily signals helps (IS) reducing aversive states provoked by social exclusion, probably due to the fact that IS is associated with emotion regulation strategies.

Disentangling interoception: insights from focal strokes affecting the perception of external and internal milieus

Interoception is the moment-to-moment sensing of the physiological condition of the body. The multimodal sources of interoception can be classified into two different streams of afferents: an internal pathway of signals arising from core structures (i.e., heart, blood vessels, and bronchi) and an external pathway of body-mapped sensations (i.e., chemosensation and pain) arising from peripersonal space. This study examines differential processing along these streams within the insular cortex (IC) and their subcortical tracts connecting frontotemporal networks. Two rare patients presenting focal lesions of the IC (insular lesion, IL) or its subcortical tracts (subcortical lesion, SL) were tested. Internally generated interoceptive streams were assessed through a heartbeat detection (HBD) task, while those externally triggered were tapped via taste, smell, and pain recognition tasks. A differential pattern was observed. The IC patient showed impaired internal signal processing while the SL patient exhibited external perception deficits. Such selective deficits remained even when comparing each patient with a group of healthy controls and a group of brain-damaged patients. These outcomes suggest the existence of distinguishable interoceptive streams. Results are discussed in relation with neuroanatomical substrates, involving a fronto-insulo-temporal network for interoceptive and cognitive contextual integration.

Self-disorders and the schizophrenia spectrum: a study of 100 first hospital admissions

INTRODUCTION

Self-disorders (SD) have been described as a core feature of schizophrenia both in classical and recent psychopathological literature. However, the specificity of SD for the schizophrenia spectrum disorders has never been demonstrated in a diagnostically heterogeneous sample, nor has the concurrent validity of SD been examined.

AIM

(1) To examine the specificity of Examination of Anomalous Self-Experiences (EASE) measured SD to the schizophrenia spectrum disorder in first contact inpatients, (2) to explore the internal consistency and factorial structure of the EASE, (3) to assess the concurrent validity of SD by exploring correlations between SD and the canonical psychopathological dimensions of schizophrenia, (4) to explore relations of SD to intelligence, sociodemographic, and extrinsic illness characteristics.

METHODS

A total of 100 consecutive first admission patients underwent a comprehensive psychopathological examination and an assessment of SD with the EASE scale. The diagnostic distribution of the EASE scores was tested with ANOVA, whereas the relations between the EASE scores and other symptomatic dimensions of schizophrenia were tested with Spearman's rho. A potential factorial structure and the internal consistency of the EASE scale were also examined.

RESULTS

SD aggregated significantly in the schizophrenia spectrum disorders, with no differences between schizophrenia and schizotypal disorders. EASE scores correlated moderately with canonical psychopathological dimensions of schizophrenia. Factor analysis of the EASE disclosed only one factor and the internal consistency of the EASE was excellent.

CONCLUSIONS

SD aggregate selectively in the schizophrenia spectrum disorders, with similar levels in schizophrenia and schizotypy. The study lends validity to the view of SD as an experiential vulnerability phenotype of the schizophrenia spectrum disorders.

When age matters: differences in facial mimicry and autonomic responses to peers' emotions in teenagers and adults

Age-group membership effects on explicit emotional facial expressions recognition have been widely demonstrated. In this study we investigated whether Age-group membership could also affect implicit physiological responses, as facial mimicry and autonomic regulation, to observation of emotional facial expressions. To this aim, facial Electromyography (EMG) and Respiratory Sinus Arrhythmia (RSA) were recorded from teenager and adult participants during the observation of facial expressions performed by teenager and adult models. Results highlighted that teenagers exhibited greater facial EMG responses to peers' facial expressions, whereas adults showed higher RSA-responses to adult facial expressions. The different physiological modalities through which young and adults respond to peers' emotional expressions are likely to reflect two different ways to engage in social interactions with coetaneous. Findings confirmed that age is an important and powerful social feature that modulates interpersonal interactions by influencing low-level physiological responses.

Disordered self in the schizophrenia spectrum: a clinical and research perspective

This article explores the phenomenological and empirical rediscovery of anomalous self-experience as a core feature of the schizophrenia spectrum disorders and presents the current status of research in this field. Historically, a disordered self was considered to be a constitutive phenotype of schizophrenia. Although the notion of a disordered self has continued to appear occasionally over the years-mainly in the phenomenologically or psychodynamically oriented literature-this notion was usually considered as a theoretical construct rather than as referring to concretely lived anomalous experiences. Empirical research on the disorders of self-experience in schizophrenia can be traced back to the US-Denmark psychopathological collaboration in the well-known adoption and high-risk studies, which aimed at identifying trait or phenotypic vulnerability features. This research was later followed by clinical work with first-admission schizophrenia patients. We offer clinical descriptions of anomalous self-experience and outline the phenomenological structures of subjectivity that are needed for grasping the nature of these anomalous experiential phenomena. What appears to underlie these experiences is an instability of the first-person perspective that threatens the basic experience of being a self-coinciding, embodied, demarcated, and persisting subject of awareness. We summarize a series of empirical studies targeting self-experience in schizophrenia performed prior to and after the construction of a phenomenologically oriented psychometric instrument for assessing anomalies of self-experience, the Examination of Anomalous Self-Experience (EASE). These empirical studies support the classic clinical intuition that anomalous self-experiences form a central phenotype of schizophrenia. Implications for diagnosis and research are briefly discussed.