Prospective memory mediated by interoceptive accuracy: a psychophysiological approach

Interoception, Affect, and Cognition in Older Adults

Interoception is the detection of signals that arise from within the body. Interoceptive sensitivity has been found to be associated with affect and cognition among younger adults, and examination of these relationships in older adult samples is beginning to emerge. Here, we take an exploratory approach to determine how demographic, affective, and cognitive variables relate to interoceptive sensitivity in neurologically normal older adults, aged 60-91 years old. Ninety-one participants completed a comprehensive neuropsychological battery, self-report questionnaires, and a heartbeat counting task to measure interoceptive sensitivity. Our findings revealed several relationships: 1) interoceptive sensitivity was inversely correlated with measures of positive emotionality: participants with higher interoceptive sensitivity tended to have lower levels of positive affect and trait extraversion; 2) interoceptive sensitivity was found to positively correlate with cognition: participants who performed better on the heartbeat-counting task also tended to perform better on a measure of delayed verbal memory; and 3) when examining the predictors of interoceptive sensitivity in a single hierarchical regression model, higher interoceptive sensitivity was related to: higher time estimation, lower positive affect, lower extraversion, and higher verbal memory. In total, the model accounted for 38% of the variability in interoceptive sensitivity (R2 = .38). These results suggest that, among older adults, interoceptive sensitivity is facilitative for aspects of cognition but perhaps disruptive for certain aspects of emotional experience.

Effect of subconscious changes in bodily response on thought shifting in people with accurate interoception

Our thought states shift from one state to another from moment to moment. The relationship between the thought shifting and bodily responses is yet to be directly examined. This exploratory study examined the influence of cardiovascular reactivity and interoception-sensing an internal bodily state-on the shifting of thought states. Participants (N = 100, 70 women) completed two tasks: the heartbeat counting task (HCT) and the vigilance task (VT). We assessed their interoceptive accuracy through their performance on the HCT. The VT was a simple sustained attention task in which participants pressed a key when the target stimulus appeared and were asked to report their thoughts. We presented subliminal vibration stimuli to induce alterations in heart rate (i.e., vibration block). Results showed that participants with higher interoceptive accuracy reported more continuation of self-referential thought (about past episodes and future plans regarding themselves) during the vibration block than did those with lower interoceptive accuracy. These results suggest that individuals with higher interoceptive accuracy are more likely to be influenced by their subliminal bodily response, resulting in divergent attention from the task and intermittent self-referential thought.

Mind your heart to bear the weight: Cardiac interoception predicts action-related visual perception when wearing a heavy backpack

Visual perception can be modulated by the physiological potential for action. For instance, it was famously shown that a geographical slant appears steeper when wearing a heavy backpack than not wearing any. However, those results are not always replicated. In the present exploratory study, we test the hypothesis that the backpack weight's effect on perception relies on the ability of the cognitive system to integrate the physiological constraint's change rather than the change itself. Young adults (n = 54) wore an electrocardiogram monitor and completed a computerised task in which photographs of real geographical slants were displayed on a screen while wearing a heavy versus light backpack. The activity of the vagus nerve, as an index of physiological adaptability, was recorded as a proxy of the physiological state during the task. The participants also completed an interoception task assessing one's ability to detect his or her own heartbeat as the index of integration ability of the cognitive system. While Bayesian analyses revealed no difference in angle estimation between carrying a heavy versus light backpack, the results indicated that interoception predicted less accurate angle estimation only when wearing a heavy backpack. In contrast, there was anecdotal evidence that vagal activity changes predicted visual perception. Interoception might thus play a crucial role in the interplay between the physiological potential for action and action-related visual perception.

Functional connectivity between interoceptive brain regions is associated with distinct health-related domains: A population-based neuroimaging study

Interoception is the sensation, perception, and integration of signals from within the body. It has been associated with a broad range of physiological and psychological processes. Further, interoceptive variables are related to specific regions and networks in the human brain. However, it is not clear whether or how these networks relate empirically to different domains of physiological and psychological health at the population level. We analysed a data set of 19,020 individuals (10,055 females, 8965 males; mean age: 63 years, age range: 45-81 years), who have participated in the UK Biobank Study, a very large-scale prospective epidemiological health study. Using canonical correlation analysis (CCA), allowing for the examination of associations between two sets of variables, we related the functional connectome of brain regions implicated in interoception to a selection of nonimaging health and lifestyle related phenotypes, exploring their relationship within modes of population co-variation. In one integrated and data driven analysis, we obtained four statistically significant modes. Modes could be categorised into domains of arousal and affect and cardiovascular health, respiratory health, body mass, and subjective health (all p < .0001) and were meaningfully associated with distinct neural circuits. Circuits represent specific neural "fingerprints" of functional domains and set the scope for future studies on the neurobiology of interoceptive involvement in different lifestyle and health-related phenotypes. Therefore, our research contributes to the conceptualisation of interoception and may lead to a better understanding of co-morbid conditions in the light of shared interoceptive structures.

Subjective judgments on direct and generative retrieval of autobiographical memory: The role of interoceptive sensibility and emotion

Autobiographical remembering is a subjective experience, and whether retrieval is perceived to occur through involuntary or voluntary, direct or generative cognitive processes is also based on subjective intuition. The present study examined factors that may contribute to the subjective judgment that occurs when we perceive memories as being retrieved directly (i.e., a memory comes to mind directly and immediately) or through generative processes (i.e., recalling a memory with effort or by using additional information). We examined the hypothesis that internal awareness (interoceptive sensibility and mindfulness traits) contributes to the physical reaction and emotional impact of memories at retrieval, which then influence the subjective judgment that memories are retrieved directly. In two online experiments, participants were asked to recall specific memories following verbal cues and to judge the retrieval process (i.e., direct or generative). We demonstrated that emotional awareness, an interoceptive sensibility scale factor, consistently predicted a high probability of direct retrieval judgments independent of other predictors of direct retrieval, such as retrieval latency and cue concreteness. This effect was especially common for concrete cues. In Experiment 2 we demonstrated that emotional awareness predicted direct retrieval judgments through the mediation of retrieval impact (physical reaction and emotional impact). These results indicate the involvement of interoceptive processing in the direct retrieval of autobiographical memories. We discuss the role of interoception in memory retrieval and present interoceptive prediction error as a novel and potentially integrative account of our findings.

Rhesus monkeys have an interoceptive sense of their beating hearts

SignificanceThe capacity to sense interoceptive signals is thought to be fundamental to broad functions including, but not limited to, homeostasis and the experience of the self. While neuroanatomical evidence suggests that nonhuman animals-namely, nonhuman primates-may possess features necessary for interoceptive processing in a way that is similar to humans, behavioral evidence of this capacity is slim. We presented macaques with audiovisual stimuli that were either synchronous or asynchronous with their heartbeat and demonstrated that they view asynchronous stimuli, whether faster or slower, for a significantly longer period than they do synchronous stimuli.

Decreased interoceptive accuracy in children with autism spectrum disorder and with comorbid attention deficit/hyperactivity disorder

Interoception refers to the awareness of internal physiological state. Several previous studies reported that people with autism spectrum disorders (ASD) and adults with attention-deficit/hyperactivity disorder (ADHD) have diverse patterns of interoception, but the extent of literature is limited and inconsistent. This study aimed to investigate the interoceptive accuracy (IA) in children with ASD, children with comorbid ASD and ADHD, and typically developing (TD) children with high and low levels of autistic traits. We administered the eye-tracking interoceptive accuracy task (EIAT) to 30 children with ASD, 20 children with comorbid ASD and ADHD, and 63 TD controls with high and low levels of autistic traits. Parent-report scales concerning ASD and ADHD symptoms were collected. ASD children with and without comorbid ADHD both exhibited lower IA than TD children. Reduced IA was also found in TD children with high-autistic traits relative to those with low-autistic traits. IA was negatively correlated with autistic and ADHD symptoms. Atypical cardiac interoception could be found in children with ASD. Difficulties in sensing and comprehending internal bodily signals in childhood may be related to both ASD and ADHD symptoms.

Atypical interoception as a common risk factor for psychopathology: A review

The inadequacy of a categorial approach to mental health diagnosis is now well-recognised, with many authors, diagnostic manuals and funding bodies advocating a dimensional, trans-diagnostic approach to mental health research. Variance in interoception, the ability to perceive one's internal bodily state, is reported across diagnostic boundaries, and is associated with atypical functioning across symptom categories. Drawing on behavioural and neuroscientific evidence, we outline current research on the contribution of interoception to numerous cognitive and affective abilities (in both typical and clinical populations), and describe the interoceptive atypicalities seen in a range of psychiatric conditions. We discuss the role that interoception may play in the development and maintenance of psychopathology, as well as the ways in which interoception may differ across clinical presentations. A number of important areas for further research on the role of interoception in psychopathology are highlighted.

Individuals with Autistic Traits Exhibit Heightened Alexithymia But Intact Interoceptive-Exteroceptive Sensory Integration

Interoceptive accuracy has been widely measured using the Heartbeat Tracking Test (HTT). We devised the novel paradigm of Interoception-Exteroception Synchronicity Judgement (IESJ) task to assess participants' interoceptive accuracy, exteroceptive accuracy, and the balancing score which reflected the ability to allocate attentions between interoceptive and exteroceptive signals. This study administered the behavioural paradigms of the HTT and the IESJ as well as other self-report scales to 119 typically-developing youths. Individuals with lower autistic traits (n = 30) showed comparable interoceptive accuracy, exteroceptive accuracy, and balancing scores as their higher autistic traits counterparts (n = 33). Taken together, the high autistic traits subgroup exhibited higher levels of alexithymia but not empathy or interoception than the low autistic traits subgroup.

Multidimensional Interoception and Autistic Traits Across life Stages: Evidence From a Novel Eye-tracking Task

Interoception is believed to underlie socio-cognitive functions which are often impaired in individuals with autism spectrum disorders (ASD). In this study, Experiment 1 examined in a sample of 114 neurotypical college students the associations among autistic traits, alexithymia, and interoceptive accuracy (IA), which was assessed by a novel paradigm "Eye-tracking Interoceptive Accuracy Task (EIAT). In Experiment 2, EIAT and the Autism Spectrum Quotient were administered to 52 preschool children, 50 adolescents, and 50 adults. Experiment 1 supported the association between autistic traits and alexithymia, but failed to support their association with multidimensional interoception. Experiment 2 strongly supported the association between age and IA. We conclude that cardiac IA differs between neurotypical age groups, but shows limited relationship with autistic traits.

Pump, person and Parfit: why the constitutive heart matters

The historical view of the heart as a source and repository of characteristics of individual persons remains prevalent in speech and literature. A more recent scientific view regards the heart as just a replaceable mechanical device, supporting a hydraulic system (the pump-view). To accept the pump-view is to reduce the historical view of the heart, and reference to it, to metaphor. To address whether this conclusion is justified, this paper investigates what constitutes an individual person over time and whether the heart has any role in that constitution. While some physical continuity may be necessary, most philosophers agree that our 'personal identity' is conferred through the persistence of 'psychological' characteristics predominantly through memory. Memory is constituted through the interplay of external and internal sensory experience-to which the heart is a major contributor. On scientific grounds alone this sensory role for the heart makes the pump-view incomplete. If our persistence as a person reflects the totality of experience codified through memory, and the heart is a central source of the internal component of that experience, then the pump-view is also misleading since the heart plays some constitutive role. More widely, if what fundamentally matters for our survival as persons is just psychological continuity, then the pump-view is irrelevant. While a 'supportive heart' may be necessary for continued embodiment, it is on the constitutive role of the heart, as part of a unique internal experience, that our individuation as persons depends.

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.

An Active Inference Approach to Interoceptive Psychopathology

Interoception refers to the process by which the nervous system senses and integrates signals originating from within the body, providing a momentary mapping of the body's internal landscape and its relationship to the outside world. Active inference is based on the premise that afferent sensory input to the brain is constantly shaped and modified by prior expectations. In this review we propose that interoceptive psychopathology results from two primary interoceptive dysfunctions: First, individuals have abnormally strong expectations of the situations that elicit bodily change (i.e., hyperprecise priors), and second, they have great difficulty adjusting these expectations when the environment changes (i.e., context rigidity). Here we discuss how these dysfunctions potentially manifest in mental illness and how interventions aimed at altering interoceptive processing can help the brain create a more realistic model of its internal state.

The impact of state and dispositional mindfulness on prospective memory: A virtual reality study

Prospective memory (PM) consists of remembering to perform an action that was previously planned. The recovery and execution of these actions require attentional resources. Mindfulness, as a state or a dispositional trait, has been associated with better attentional abilities while mind wandering is linked with attentional failures. In this study, we investigated the impact of mindfulness on PM. Eighty participants learned 15 cue-action associations. They were, then, asked to recall the actions at certain moments (time-based items) or places (event-based items) during a walk in a virtual town. Before the PM task, participants were randomly assigned to a mindfulness or mind wandering (control condition) session. Dispositional mindfulness was measured via the Five Facets Mindfulness Questionnaire (FFMQ). Although considered as two opposite states, we did not report any difference between the two groups on PM abilities. Nevertheless, the natural tendency to describe one's own sensations (the Describing facet of the FFMQ) predicted time-based performance in both groups. We discuss different hypotheses to explain this finding in light of recent findings on the impact of mind wandering on future oriented cognition. Our main observation is a positive link between the Describing facet and time-based PM performances. We propose that this link could be due to the common association of this mindfulness facets and PM with attentional and interoceptive abilities. Additional studies are needed to explore this hypothesis.

A multidimensional and multi-feature framework for cardiac interoception

Interoception (the sensing of inner-body signals) is a multi-faceted construct with major relevance for basic and clinical neuroscience research. However, the neurocognitive signatures of this domain (cutting across behavioral, electrophysiological, and fMRI connectivity levels) are rarely reported in convergent or systematic fashion. Additionally, various controversies in the field might reflect the caveats of standard interoceptive accuracy (IA) indexes, mainly based on heartbeat detection (HBD) tasks. Here we profit from a novel IA index (md) to provide a convergent multidimensional and multi-feature approach to cardiac interoception. We found that outcomes from our IA-md index are associated with -and predicted by- canonical markers of interoception, including the hd-EEG-derived heart-evoked potential (HEP), fMRI functional connectivity within interoceptive hubs (insular, somatosensory, and frontal networks), and socio-emotional skills. Importantly, these associations proved more robust than those involving current IA indexes. Furthermore, this pattern of results persisted when taking into consideration confounding variables (gender, age, years of education, and executive functioning). This work has relevant theoretical and clinical implications concerning the characterization of cardiac interoception and its assessment in heterogeneous samples, such as those composed of neuropsychiatric patients.

Exercise and Prospective Memory

The purpose of this paper was to review the literature to evaluate the potential effects of exercise on prospective memory (PM). A narrative review was employed. In this review, we provide a brief description of PM; indicate the effects of PM on health; evaluate the effects of age and neurological impairment on PM; examine the neural correlates of PM; provide a description of specific components that subserve PM; identify non-behavioral strategies used to enhance PM; and evaluate the literature and plausibility through which exercise behavior may influence PM. Regarding the latter, this paper aims to burgeon the development of a new research paradigm that will play a critical role in patient health, given that memory function, and in particular, the prospective (vs. retrospective) component of memory, is highly sensitive to aging and is critically associated with health status. This is an emerging line of research that has critical implications for patient health.

Interoception beyond homeostasis: affect, cognition and mental health

Interoception refers to the sensing of the internal state of one's body. Interoception is distinct from the processing of sensory information concerning external (non-self) stimuli (e.g. vision, hearing, touch and smell) and is the afferent axis to internal (autonomic and hormonal) physiological control. However, the impact of interoception extends beyond homeostatic/allostatic reflexes: it is proposed to be fundamental to motivation, emotion (affective feelings and behaviours), social cognition and self-awareness. This view is supported by a growing body of experimental evidence that links peripheral physiological states to mental processes. Within this framework, the representation of self is constructed from early development through continuous integrative representation of biological data from the body, to form the basis for those aspects of conscious awareness grounded on the subjective sense of being a unique individual. This theme issue of the Philosophical Transactions of the Royal Society B draws together state-of-the-art knowledge concerning theoretical, experimental and clinical facets of interoception with the emphasis on cognitive and affective neuroscience. The multidisciplinary and cross-disciplinary perspectives represented in this theme issue disseminate and entrench knowledge about interoception across the scientific community and provide a reference for the conceptualization and further study of interoception across behavioural sciences.