Social Power Increases Interoceptive Accuracy

Longitudinal microstructural changes in 18 amygdala nuclei resonate with cortical circuits and phenomics

The amygdala nuclei modulate distributed neural circuits that most likely evolved to respond to environmental threats and opportunities. So far, the specific role of unique amygdala nuclei in the context processing of salient environmental cues lacks adequate characterization across neural systems and over time. Here, we present amygdala nuclei morphometry and behavioral findings from longitudinal population data (>1400 subjects, age range 40-69 years, sampled 2-3 years apart): the UK Biobank offers exceptionally rich phenotyping along with brain morphology scans. This allows us to quantify how 18 microanatomical amygdala subregions undergo plastic changes in tandem with coupled neural systems and delineating their associated phenome-wide profiles. In the context of population change, the basal, lateral, accessory basal, and paralaminar nuclei change in lockstep with the prefrontal cortex, a region that subserves planning and decision-making. The central, medial and cortical nuclei are structurally coupled with the insular and anterior-cingulate nodes of the salience network, in addition to the MT/V5, basal ganglia, and putamen, areas proposed to represent internal bodily states and mediate attention to environmental cues. The central nucleus and anterior amygdaloid area are longitudinally tied with the inferior parietal lobule, known for a role in bodily awareness and social attention. These population-level amygdala-brain plasticity regimes in turn are linked with unique collections of phenotypes, ranging from social status and employment to sleep habits and risk taking. The obtained structural plasticity findings motivate hypotheses about the specific functions of distinct amygdala nuclei in humans.

Affect and Social Judgment: The Roles of Physiological Reactivity and Interoceptive Sensitivity

Humans imbue the objects of their perception with affective meaning, a phenomenon called affective realism. The affective realism hypothesis proposes that a brain continually predicts the meaning of sensations (e.g., identifying a sound as a siren, or a visual array as a face) in part by representing the current state of the body and the immediate physiological impact that similar sensory events have entailed in the past. However, the precise contribution of physiological activity to experiences of affective realism remains unknown. In the present study, participants' peripheral physiological activity was recorded while they made social evaluative judgments of target faces displaying neutral expressions. Target faces were shown concurrent with affective images that were suppressed from reportable awareness using continuous flash suppression. Results revealed evidence of affective realism-participants judged target faces more positively when paired with suppressed positive stimuli than suppressed negative stimuli-but this effect was significantly less pronounced among individuals higher in cardiac interoceptive sensitivity. Moreover, while some modest differences in peripheral physiological activity were observed across suppressed affective stimulus conditions, physiological reactivity to affective stimuli did not directly predict social evaluative judgments. We explore the implications of these findings with respect to both theories of emotion and theories detailing a role for interoception in experiences of first-person subjectivity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42761-022-00114-9.

Sex differences in interoceptive accuracy: A meta-analysis

Interoceptive accuracy, the ability to correctly perceive internal signals arising from the body, is thought to be disrupted in numerous mental and physical health conditions. Whilst evidence suggests poorer interoceptive accuracy in females compared to males, raising the possibility that interoceptive differences may relate to sex differences in mental and physical health, results concerning sex differences in interoceptive accuracy are mixed. Given such ambiguity, this meta-analysis aimed to establish the presence or absence of sex differences in interoceptive accuracy across cardiac, respiratory, and gastric domains. A review of 7956 abstracts resulted in 93 eligible studies. Results demonstrated superior accuracy in males across cardiac, but not gastric, tasks, while findings on respiratory tasks were mixed. Effect sizes were consistent across cardiac tasks, but instability and/or moderate heterogeneity was observed across other domains, likely due to the small number of eligible studies. Despite such limitations, results indicate the possibility of sex differences across interoception tasks and domains. Methodological limitations concerning the influence of physiological factors, and directions for future research are discussed.

Mindfulness and Behavior Change

Initiating and maintaining behavior change is key to the prevention and treatment of most preventable chronic medical and psychiatric illnesses. The cultivation of mindfulness, involving acceptance and nonjudgment of present-moment experience, often results in transformative health behavior change. Neural systems involved in motivation and learning have an important role to play. A theoretical model of mindfulness that integrates these mechanisms with the cognitive, emotional, and self-related processes commonly described, while applying an integrated model to health behavior change, is needed. This integrative review (1) defines mindfulness and describes the mindfulness-based intervention movement, (2) synthesizes the neuroscience of mindfulness and integrates motivation and learning mechanisms within a mindful self-regulation model for understanding the complex effects of mindfulness on behavior change, and (3) synthesizes current clinical research evaluating the effects of mindfulness-based interventions targeting health behaviors relevant to psychiatric care. The review provides insight into the limitations of current research and proposes potential mechanisms to be tested in future research and targeted in clinical practice to enhance the impact of mindfulness on behavior change.

Using bodily postures to reduce anxiety and improve interoception: A comparison between powerful and neutral poses

BACKGROUND

Previous research has shown that anxiety syndromes are highly prevalent among university students. Effective treatments are needed to reduce the burden of anxiety in this population. Powerful postures have been found to impact affective states, as well as interoception (i.e. the ability to perceive inner bodily signals). However, no previous study has compared the effects of powerful- and neutral postures in regards to anxiety and interoceptive ability.

METHODS

The first part of the study measured the single-session effect of adopting powerful- vs. neutral postures on students' (n = 57) interoceptive ability and state anxiety. The second part of the study measured the effect of adopting powerful or neutral postures twice daily for two weeks, on individuals' interoceptive ability and trait anxiety.

RESULTS

State anxiety decreased in both conditions whereas interoceptive accuracy only increased in the power posing condition after a single session. Interoceptive accuracy increased in both groups after two weeks of training.

LIMITATIONS

The study included no comparison to a condition where individuals adopted their natural (i.e. usual) bodily posture.

CONCLUSIONS

Embodiment interventions that include elements of adopting an open or expansive bodily posture whilst maintaining a self-focus, can help to reduce state anxiety and improve interoceptive accuracy in student populations. Power posing does not seem to be superior to holding a neutral posture to improve interoceptive accuracy or anxiety. One reason therefore could be that both conditions include the manipulation of self-focus and a postural change that diverges from individuals' normal posture.

Using bodily postures in the treatment of anorexia nervosa: Effects of power posing on interoception and affective states

OBJECTIVE

Power posing involves the adoption of an expansive bodily posture. This study examined whether power posing could benefit individuals with anorexia nervosa (AN) and women with normal weight in regards to interoceptive ability and affective states.

METHOD

Participants included 50 inpatients and outpatients with AN as well as 51 normal-weight women. Interoceptive accuracy (IAcc), measured by the heartbeat tracking task and interoceptive sensibility (IS), measured by confidence ratings, were assessed at baseline, after a single power posing session and after 1 week of daily training. Also, the short-term effects of power posing on subjective feelings of dominance, pleasantness, and arousal were investigated.

RESULTS

Both groups increased in their IAcc after one power posing session. Also, there was a significant main effect of time on feelings of dominance and pleasantness in the short-term. Women with AN displayed lower levels of IS, dominance, and pleasantness as well as higher levels of arousal than women without AN.

DISCUSSION

These findings suggest that power posing has the potential to increase IAcc, subjective feelings of power and pleasant affect in the short-term. Further research should investigate which mechanisms foster the effectiveness of this intervention to tailor it to the needs of women with AN.

When smiles (and frowns) speak words: Does power impact the correspondence between self-reported affect and facial expressions?

Self-reported experiences are often poor indicators of outward expressions. Here we examine social power as a variable that may impact the relationship between self-reported affect and facial expressions. Earlier studies addressing this issue were limited by focusing on a single facial expression (smiling) and by using different, less sensitive methods that yielded mostly null results. Sampling, for the first time, self-reported affect repeatedly in response to different negative, neutral and positive stimuli, and measuring concurrent facial muscle activation via electromyography, we found that high power (vs. baseline) increased the correspondence between self-reported positive affect and smiling. There was also an indication that high power (vs. baseline) bolstered the association between self-reported negative affect and frowning but the effect did not pass more stringent criteria for significance (p ≤ .005) and was therefore deemed inconclusive. The prediction that low power (vs. baseline) decreases the correspondence between self-reported affect and smiling and frowning facial expressions was not supported. Taken together, it would appear that (high) power can impact the relationship between self-reported affect and facial expressions, but it remains to be seen whether this effect extends beyond smiling facial expressions.

Improving interoceptive ability through the practice of power posing: A pilot study

Interoception refers to the detection and perception of signals from the inner body. Deficits in this domain have been linked to psychopathologies, prompting the search for strategies to improve this ability. Preliminary studies have shown that interoception could be enhanced through the manipulation of subjective feelings of power. We tested the effects of adopting powerful postures on different facets of interoception. Firstly, we measured the impact of a single power posing session on interoceptive ability in 41 healthy females. Then, the same participants were randomly assigned to two conditions (daily power posing practice vs. no practice). After one week the conditions alternated. Interoceptive accuracy, measured by the heartbeat tracking task, interoceptive sensibility, measured by the Body Perception Questionnaire (BPQ) and confidence ratings, as well as subjective feelings of power were assessed at baseline, after a single power posing session and after one week of training. A single power posing session significantly increased individuals' interoceptive accuracy. Also, power posing reduced individuals' scores on the BPQ after one week of daily practice and increased subjective feelings of power after one session and one week of daily practice. These findings suggest that adopting powerful postures has the potential to increase interoceptive accuracy, as well as subjective feelings of power, and to reduce interoceptive sensibility, measured by questionnaire.

Testosterone facilitates the sense of agency

Sense of agency (SoA) refers to feelings of being in control of one's actions. Evidence suggests that SoA might contribute towards higher-order feelings of personal control - a key attribute of powerful individuals. Whether testosterone, a steroid hormone linked to power in dominance hierarchies, also influences the SoA is not yet established. In a repeated-measures design, 26 females participated in a double-blind, placebo-controlled trial to test the effects of 0.5 mg testosterone on SoA, using an implicit measure based upon perceived shifts in time between a voluntary action and its outcome. Illusions of control, as operationalized by optimism in affective forecasting, were also assessed. Testosterone increased action binding but there was no significant effect on tone binding. Affective forecasting was found to be significantly more positive on testosterone. SoA and optimistic expectations are basic manifestations of power which may contribute to feelings of infallibility often associated with dominance and testosterone.