Opposing Association of Situational and Chronic Loneliness with Interpersonal Distance

Larger comfortable interpersonal distances in adults exposed to child maltreatment: The role of depressive symptoms and social anxiety

Previous studies report a preference for larger comfortable interpersonal distance (CIPD) in individuals with child maltreatment (CM) when being approached by others. Yet, research on approaching others, as opposed to being approached, as well as on potential effects of social anxiety and depression is lacking. We investigated if CM and depressive symptoms influence CIPD and if social anxiety mediates the possible association of CM and CIPD when approaching a female stranger. One hundred ten participants with CM (CM) and 58 participants without CM (non-CM) experiences performed the stop-distance paradigm and stopped first when feeling uncomfortable (D1) and again when feeling very uncomfortable (D2). CM experiences were associated with a preference for larger CIPD, independent of depressive symptoms. All CM subtypes were associated with a larger D2. The relationship between CM and CIPD was partially mediated by social anxiety. These novel findings can help to develop interventions strengthening socially relevant skills and processes in those affected by CM, targeting alterations in social anxiety and depression.

Let me in: The neural correlates of inclusion motivation in loneliness

BACKGROUND

While it is well-established that humans possess an innate need for social belonging, the neural mechanisms underlying motivation for connection are still largely unknown. We propose that inclusion motivation - measured through the effort that individuals are willing to invest to be included in social interactions - may serve as one of the basic building blocks of social behavior and may change in lonely individuals.

METHODS

Following the screening of 303 participants, we scanned 30 low- and 28 high-loneliness individuals with functional magnetic resonance imaging while they performed the Active Inclusion Task (AIT). The AIT assesses the participants' levels of effort invested in influencing their inclusion during classic Cyberball conditions of fair play and exclusion.

RESULTS

High- compared to low-loneliness individuals showed higher urgency for inclusion, specifically during fair play, which correlated with higher activity in the right thalamus. Furthermore, in high-loneliness individuals, we found increased functional connectivity between the thalamus and the temporoparietal junction, putamen, and insula.

LIMITATIONS

Participants interacted with computerized avatars, reducing ecological validity. Additionally, although increasing inclusion in the task required action, the physical demand was not high. Additional limitations are discussed.

CONCLUSIONS

Inclusion motivation in loneliness is heightened during fair but not exclusionary interactions, and is linked to activity in brain regions implicated in appetitive behavior and social cognition. The findings indicate that lonely individuals may view threat in inclusionary interactions, prompting them to take action to regain connection. This suggests that inclusion motivation may help explain social difficulties in loneliness.

Childhood maltreatment is linked to larger preferred interpersonal distances towards friends and strangers across the globe

Childhood maltreatment (CM) is thought to be associated with altered responses to social stimuli and interpersonal signals. However, limited evidence exists that CM is linked to larger comfortable interpersonal distance (CID) - the physical distance humans prefer towards others during social interactions. However, no previous study has investigated this association in a comprehensive sample, yielding sufficient statistical power. Moreover, preliminary findings are limited to the European region. Finally, it is unclear how CM affects CID towards different interaction partners, and whether CID is linked to social functioning and attachment. To address these outstanding issues, adults (N = 2986) from diverse cultures and socio-economic strata completed a reaction time task measuring CID towards an approaching stranger and friend. Higher CM was linked to a larger CID towards both friends and strangers. Moreover, insecure attachment and less social support were associated with larger CID. These findings demonstrate for the first time that CM affects CID across countries and cultures, highlighting the robustness of this association.

Loneliness and brain rhythmic activity in resting state: an exploratory report

Recent studies using resting-state functional magnetic resonance imaging have shown that loneliness is associated with altered blood oxygenation in several brain regions. However, the relationship between loneliness and changes in neuronal rhythm activity in the brain remains unclear. To evaluate brain rhythm, we conducted an exploratory resting-state electroencephalogram (EEG) study of loneliness. We recorded resting-state EEG signals from 139 participants (94 women; mean age = 19.96 years) and analyzed power spectrum density (PSD) and functional connectivity (FC) in both the electrode and source spaces. The PSD analysis revealed significant correlations between loneliness scores and decreased beta-band powers, which may indicate negative emotion, attention, reward, and/or sensorimotor processing. The FC analysis revealed a trend of alpha-band FC associated with individuals' loneliness scores. These findings provide new insights into the neural basis of loneliness, which will facilitate the development of neurobiologically informed interventions for loneliness.

A translational neuroscience perspective on loneliness: Narrative review focusing on social interaction, illness and oxytocin

This review addresses key findings on loneliness from the social, neurobiological and clinical fields. From a translational perspective, results from studies in humans and animals are included, with a focus on social interaction, mental and physical illness and the role of oxytocin in loneliness. In terms of social interactions, lonely individuals tend to exhibit a range of abnormal behaviors based on dysfunctional social cognitions that make it difficult for them to form meaningful relationships. Neurobiologically, a link has been established between loneliness and the hypothalamic peptide hormone oxytocin. Since social interactions and especially social touch regulate oxytocin signaling, lonely individuals may have an oxytocin imbalance, which in turn affects their health and well-being. Clinically, loneliness is a predictor of physical and mental illness and leads to increased morbidity and mortality. There is evidence that psychopathology is both a cause and a consequence of loneliness. The final section of this review summarizes the findings from social, neurobiological and clinical perspectives to present a new model of the complex construct of loneliness.

Loneliness corresponds with neural representations and language use that deviate from shared cultural perceptions

The word zeitgeist refers to common perceptions shared in a given culture. Meanwhile, a defining feature of loneliness is feeling that one's views are not shared with others. Does loneliness correspond with deviating from the zeitgeist? Across two independent brain imaging datasets, lonely participants' neural representations of well-known celebrities strayed from group-consensus neural representations in the medial prefrontal cortex-a region that encodes and retrieves social knowledge (Studies 1 A/1B: N = 40 each). Because communication fosters social connection by creating shared reality, we next asked whether lonelier participants' communication about well-known celebrities also deviates from the zeitgeist. Indeed, when a strong group consensus exists, lonelier individuals use idiosyncratic language to describe well-known celebrities (Study 2: N = 923). Collectively, results support lonely individuals' feeling that their views are not shared. This suggests loneliness may not only reflect impoverished relationships with specific individuals, but also feelings of disconnection from prevalently shared views of contemporary culture.

Perception of interpersonal distance and social distancing before and during COVID-19 pandemic

Since COVID-19 is easily transmitted among people in close physical proximity, the focus of epidemiological policy during the COVID-19 crisis included major restrictions on interpersonal distance. However, the way in which distance restrictions affected spatial perception is unclear. In the current study, we examined interpersonal distance preferences and perceptions at three time points: pre-pandemic, early post-pandemic, and late post-pandemic. The results indicate that following the pandemic outbreak, people perceived others as farther away than they actually were, suggesting that the distance restrictions were associated with an enlargement of perceived interpersonal distance. Interestingly, however, people maintained the same distance from one another as before the outbreak, indicating no change in actual distance behavior due to the risk of infection. These findings suggest that COVID-19 was associated with a change in the way distance is perceived, while in practice, people maintain the same distance as before. In contrast, COVID-related anxiety predicted both a preference for maintaining a greater distance and a bias toward underestimating perceived distance from others. Thus, individuals who were highly fearful of COVID-19 perceived other people to be closer than they actually were and preferred to maintain a larger distance from them. The results suggest that subjective risk can lead to an increased perception of danger and a subsequent change in behavior. Taken together, even when behaviors should logically change, the decision-making process can be based on distorted perceptions. This insight may be used to predict public compliance.

Away from the herd: loneliness as a dysfunction of social alignment

The tendency of all humans to experience loneliness at some point in their lives implies that it serves an adaptive function. Building on biological theories of herding in animals, according to which collective movement emerges from local interactions that are based on principles of attraction, repulsion and alignment, we propose an approach that synthesizes these principles with theories of loneliness in humans. We present here the 'herding model of loneliness' that extends these principles into the psychological domain. We hold that these principles serve as basic building blocks of human interactions and propose that distorted attraction and repulsion tendencies may lead to inability to align properly with others, which may be a core component in loneliness emergence and perpetuation. We describe a neural model of herding in humans and suggest that loneliness may be associated with altered interactions between the gap/error detection, reward signaling, threat and observation-execution systems. The proposed model offers a framework to predict the behavior of lonely individuals and thus may inform intervention designs for reducing loneliness intensity.

Social Withdrawal, Loneliness, and Health in Schizophrenia: Psychological and Neural Mechanisms

BACKGROUND AND HYPOTHESIS

Some of the most debilitating aspects of schizophrenia and other serious mental illnesses (SMI) are the impairments in social perception, motivation, and behavior that frequently accompany these conditions. These impairments may ultimately lead to chronic social disconnection (ie, social withdrawal, objective isolation, and perceived social isolation or loneliness), which may contribute to the poor cardiometabolic health and early mortality commonly observed in SMI. However, the psychological and neurobiological mechanisms underlying relationships between impairments in social perception and motivation and social isolation and loneliness in SMI remain incompletely understood.

STUDY DESIGN

A narrative, selective review of studies on social withdrawal, isolation, loneliness, and health in SMI.

STUDY RESULTS

We describe some of what is known and hypothesized about the psychological and neurobiological mechanisms of social disconnection in the general population, and how these mechanisms may contribute to social isolation and loneliness, and their consequences, in individuals with SMI.

CONCLUSIONS

A synthesis of evolutionary and cognitive theories with the "social homeostasis" model of social isolation and loneliness represents one testable framework for understanding the dynamic cognitive and biological correlates, as well as the health consequences, of social disconnection in SMI. The development of such an understanding may provide the basis for novel approaches for preventing or treating both functional disability and poor physical health that diminish the quality and length of life for many individuals with these conditions.

Homeostatic Regulation of Energetic Arousal During Acute Social Isolation: Evidence From the Lab and the Field

Recent evidence suggests that social contact is a basic need governed by a social homeostatic system. Little is known, however, about how conditions of altered social homeostasis affect human psychology and physiology. Here, we investigated the effects of 8 hr of social isolation on psychological and physiological variables and compared this with 8 hr of food deprivation in a lab experiment (N = 30 adult women). Social isolation led to lowered self-reported energetic arousal and heightened fatigue, comparable with food deprivation. To test whether these findings would extend to a real-life setting, we conducted a preregistered field study during a COVID-19 lockdown (N = 87 adults; 47 women). The drop in energetic arousal after social isolation observed in the lab replicated in the field study for participants who lived alone or reported high sociability, suggesting that lowered energy could be part of a homeostatic response to the lack of social contact.

Retrospective cross-sectional study examining the association between loneliness and unmet healthcare needs among middle-aged and older adults using the Canadian Longitudinal Study of Aging (CLSA)

OBJECTIVES

Our primary objective was to estimate the association between loneliness and unmet healthcare needs and if the association changes when adjusted for demographic and health factors. Our secondary objective was to examine the associations by gender (men, women, gender diverse).

DESIGN, SETTING, PARTICIPANTS

Retrospective cross-sectional data from 44 423 community-dwelling Canadian Longitudinal Study on Aging participants aged 45 years and older were used.

PRIMARY OUTCOME MEASURE

Unmet healthcare needs are measured by asking respondents to indicate (yes, no) if there was a time when they needed healthcare in the last 12 months but did not receive it.

RESULTS

In our sample of 44 423 respondents, 8.5% (n=3755) reported having an unmet healthcare need in the previous 12 months. Lonely respondents had a higher percentage of unmet healthcare needs (14.4%, n=1474) compared with those who were not lonely (6.7%, n=2281). Gender diverse had the highest percentage reporting being lonely and having an unmet healthcare need (27.3%, n=3), followed by women (15.4%, n=887) and men (13.1%, n=583). In our logistic regression, lonely respondents had higher odds of having an unmet healthcare need in the previous 12 months than did not lonely (adjusted odd ratios (aOR) 1.80, 95% CI 1.64 to 1.97), adjusted for other covariates. In the gender-stratified analysis, loneliness was associated with a slightly greater likelihood of unmet healthcare needs in men (aOR 1.90, 95% CI 1.64 to 2.19) than in women (aOR 1.73, 95% CI 1.53 to 1.95). In the gender diverse, loneliness was also associated with increased likelihood of having an unmet healthcare need (aOR 1.38, 95% CI 0.23 to 8.29).

CONCLUSIONS

Loneliness was related to unmet healthcare needs in the previous 12 months, which may suggest that those without robust social connections experience challenges accessing health services. Gender-related differences in loneliness and unmet needs must be further examined in larger samples.

Psychological impact of COVID-19: A cross-lagged network analysis from the English Longitudinal Study of Aging COVID-19 database

Background

The COVID-19 pandemic and its subsequent health restrictions had an unprecedented impact on mental health, contributing to the emergence and reinforcement of various psychopathological symptoms. This complex interaction needs to be examined especially in a vulnerable population such as older adults.

Objective

In the present study we analyzed network structures of depressive symptoms, anxiety, and loneliness from the English Longitudinal Study of Aging COVID-19 Substudy over two waves (Months of June-July and November-December 2020).

Methods

For this purpose, we use measures of centrality (expected and bridge-expected influence) in addition to the Clique Percolation method to identify overlapping symptoms between communities. We also use directed networks to identify direct effects between variables at the longitudinal level.

Results

UK adults aged >50 participated, Wave 1: 5,797 (54% female) and Wave 2: 6,512 (56% female). Cross-sectional findings indicated that difficulty relaxing, anxious mood, and excessive worry symptoms were the strongest and similar measures of centrality (Expected Influence) in both waves, while depressive mood was the one that allowed interconnection between all networks (bridge expected influence). On the other hand, sadness and difficulty sleeping were symptoms that reflected the highest comorbidity among all variables during the first and second waves, respectively. Finally, at the longitudinal level, we found a clear predictive effect in the direction of the nervousness symptom, which was reinforced by depressive symptoms (difficulties in enjoying life) and loneliness (feeling of being excluded or cut off from others).

Conclusion

Our findings suggest that depressive, anxious, and loneliness symptoms were dynamically reinforced as a function of pandemic context in older adults in the UK.

Loneliness, student engagement, and academic achievement during emergency remote teaching during COVID-19: the role of the God locus of control

The COVID-19 pandemic has raised many problems in the education sector, one of which is the increasing trend toward student loneliness owing to a lack of interpersonal connections in online learning activities. The present study explicitly aims to examine the relationship between loneliness and academic achievement for university students in Indonesia. Moreover, we propose moderating God's locus of control (i.e., God's control over behavior-related learning) (GLC) and learning student engagement, playing mediating roles in these relationships. The data were collected from 324 respondents among university students in Indonesia during emergency remote teaching. The moderated-mediated regression analysis using Hayes' PROCESS macro found loneliness negatively related to engagement and academic achievement. Student engagement had a positive relationship with academic achievement and served as a mediator between loneliness and academic achievement. Furthermore, GLC was found to moderate the relationship between loneliness and learning engagement as well as loneliness and academic achievement. This study's findings uncover GLC's role as a boundary condition, and confirms that learning-engagement intermediates the relationship between loneliness and academic achievement. Students with high perceived God control tend to anticipate the impact of loneliness on learning behavior amid isolation and loneliness because of the pandemic.

Decreased self-reported receiving of social touch and social support predict loneliness in healthy adults

Loneliness has emerged as a public health concern. Previous research has reported its deleterious effects on physical and mental health; however, some specific psychophysiological mechanisms in healthy adults remain to be elucidated. The aim of the current study is to investigate whether self-reported social support and social touch (giving and receiving social touch), as well as resting heart rate variability (HRV), are significant negative predictors of loneliness in healthy adults. The study sample consists of 120 healthy students (50% female) with a mean age of 21.85 years old (DP= 2.21). The students were asked to complete a psychiatric screening questionnaire utilizing loneliness, social support, and social touch scales. HRV was derived from an electrocardiographic signal recorded for 15 min, with the participant relaxed in a supine position. Linear regression analyses were conducted to evaluate loneliness as a function of social support, social touch (giving or receiving touch), and resting HRV. The results show that social support (p< 0.001) and social touch, specifically receiving touch (p< 0.002), accounted for a significant proportion of the variance in loneliness. However, neither giving touch nor resting HRV was a significant predictor of loneliness. The current study highlights specific psychosocial factors in healthy adults that should be considered as promising pathways in order to reduce or work toward preventing loneliness, thus promoting better health and well-being.

Behavioral and Neural Dissociation of Social Anxiety and Loneliness

Loneliness is a public health concern with detrimental effects on physical and mental well-being. Given phenotypical overlaps between loneliness and social anxiety (SA), cognitive-behavioral interventions targeting SA might be adopted to reduce loneliness. However, whether SA and loneliness share the same underlying neurocognitive mechanisms is still an elusive question. The current study aimed at investigating to what extent known behavioral and neural correlates of social avoidance in SA are evident in loneliness. We used a prestratified approach involving 42 (21 females) participants with high loneliness (HL) and 40 (20 females) participants with low loneliness (LL) scores. During fMRI, participants completed a social gambling task to measure the subjective value of engaging in social situations and responses to social feedback. Univariate and multivariate analyses of behavioral and neural data replicated known task effects. However, although HL participants showed increased SA, loneliness was associated with a response pattern clearly distinct from SA. Specifically, contrary to expectations based on SA differences, Bayesian analyses revealed moderate evidence for equal subjective values of engaging in social situations and comparable amygdala responses to social decision-making and striatal responses to positive social feedback in both groups. Moreover, while explorative analyses revealed reduced pleasantness ratings, increased striatal activity, and decreased striatal-hippocampal connectivity in response to negative computer feedback in HL participants, these effects were diminished for negative social feedback. Our findings suggest that, unlike SA, loneliness is not associated with withdrawal from social interactions. Thus, established interventions for SA should be adjusted when targeting loneliness.SIGNIFICANCE STATEMENT Loneliness can cause serious health problems. Adapting well-established cognitive-behavioral therapies targeting social anxiety might be promising to reduce chronic loneliness given a close link between both constructs. However, a better understanding of behavioral and neurobiological factors associated with loneliness is needed to identify which specific mechanisms of social anxiety are shared by lonely individuals. We found that lonely individuals show a consistently distinct pattern of behavioral and neural responsiveness to social decision-making and social feedback compared with previous findings for social anxiety. Our results indicate that loneliness is associated with a biased emotional reactivity to negative events rather than social avoidance. Our findings thus emphasize the distinctiveness of loneliness from social anxiety and the need for adjusted psychotherapeutic protocols.

Altered activation in the action observation system during synchronization in high loneliness individuals

Lonely people tend to evaluate social exchanges negatively and to display difficulties in interactions. Interpersonal synchronization is crucial for achieving positive interactions, promoting affinity, closeness, and satisfaction. However, little is known about lonely individuals' ability to synchronize and about their brain activity while synchronizing. Following the screening of 303 participants, we recruited 32 low and 32 high loneliness participants. They were scanned while engaged in movement synchronization, using a novel dyadic interaction paradigm. Results showed that high loneliness individuals exhibited a reduced ability to adapt their movement to their partner's movement. Intriguingly, during movement adaptation periods, high loneliness individuals showed increased activation in the action observation (AO) system, specifically in the inferior frontal gyrus and the inferior parietal lobule. They did not show increased activation in the dorsomedial prefrontal cortex, which in the context of synchronization was suggested to be related to gap-monitoring. Based on these findings, we propose a model according to which lonely people may require stronger activation of their AO system for alignment, to compensate for some deficiency in their synchronization ability. Despite this hyperactivation, they still suffer from reduced synchronization capacity. Consequently, synchronization may be a relevant intervention area for the amelioration of loneliness.

Touched by loneliness-how loneliness impacts the response to observed human touch: a tDCS study

Lonely people often crave connectedness. However, they may also experience their environment as threatening, entering a self-preserving state that perpetuates loneliness. Research shows conflicting evidence about their response to positive social cues, and little is known about their experience of observed human touch. The right inferior frontal gyrus (rIFG) is part of an observation-execution network implicated in observed touch perception. Correlative studies also point to rIFG's involvement in loneliness. We examined the causal effect of rIFG anodal transcranial direct current stimulation on high- and low-loneliness individuals observing human touch. In a cross-over design study, 40 participants watched pictures of humans or objects touching or not touching during anodal and sham stimulations. Participants indicated whether pictures contained humans or objects, and their reaction time was measured. Results show that the reaction time of low-loneliness individuals to observed human touch was significantly slower during anodal stimulation compared to high-loneliness individuals, possibly due to them being more emotionally distracted by it. Lonely individuals also reported less liking of touch. Our findings support the notion that lonely individuals are not drawn to positive social cues. This may help explain the perpetuation of loneliness, despite social opportunities that could be available to lonely people.

Cognitive and Behavioral Patterns across Psychiatric Conditions

Psychiatric conditions represent a highly heterogeneous group of disorders associated with chronic distress and a sharp decline in quality of life [...].