Article

Perceived Social Isolation is Associated with Altered Functional Connectivity in Neural Networks Associated with Tonic Alertness and Executive Control

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Abstract

Perceived social isolation (PSI), colloquially known as loneliness, is associated with selectively altered attentional, cognitive, and affective processes in humans, but the neural mechanisms underlying these adjustments remain largely unexplored. Behavioral, eye tracking, and neuroimaging research has identified associations between PSI and implicit hypervigilance for social threats. Additionally, selective executive dysfunction has been evidenced by reduced prepotent response inhibition in social Stroop and dichotic listening tasks. Given that PSI is associated with pre-attentional processes, PSI may also be related to altered resting-state functional connectivity (FC) in the brain. Therefore, we conducted the first resting-state fMRI FC study of PSI in healthy young adults. Five-minute resting-state scans were obtained from 55 participants (31 females). Analyses revealed robust associations between PSI and increased brain-wide FC in areas encompassing the right central operculum and right supramarginal gyrus, and these associations were not explained by depressive symptomatology, objective isolation, or demographics. Further analyses revealed that PSI was associated with increased FC between several nodes of the cingulo-opercular network, a network known to underlie the maintenance of tonic alertness. These regions encompassed the bilateral insula/frontoparietal opercula and ACC/pre-SMA. In contrast, FC between the cingulo-opercular network and right middle/superior frontal gyrus was reduced, a finding associated with diminished executive function in prior literature. We suggest that, in PSI, increased within-network cingulo-opercular FC may be associated with hypervigilance to social threat, whereas reduced right middle/superior frontal gyrus FC to the cingulo-opercular network may be associated with diminished impulse control.

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... Its cognitive and affective characteristics also include heightened emotional reactivity to social stimuli, often in the context of reduced cognitive control 25,26 . Accordingly, brain differences related to the experience of loneliness have been reported in visual cortices, as well as visual attention networks, limbic structures, and prefrontal cortex [27][28][29][30][31] . ...
... behavioral sequelae of loneliness, which involves an attentional bias for negative social cues in the context of reduced cognitive control [22][23][24]30 . Consistent with these earlier neuroimaging results, we confirm gray matter deviations related to loneliness in attentional and limbic networks in UK Biobank participants. ...
... Further, at the population-level, we have associated loneliness with shifted functional connectivity within the visual sensory cortex and between the visual system and other canonical brain networks, paralleling early task functional MRI experiments 22 . Consistent with this, Layden et al. 30 recently proposed a neural account of loneliness that included heightened functional connectivity within a cingulo-opercular vigilance network and reduced connectivity between this network and parietal brain regions implicated in control processes. In line with this previous research, we also observed consistent volumetric alterations in right inferior parietal and cingulo-opercular regions as well as in dorsolateral prefrontal cortex. ...
Article
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Humans survive and thrive through social exchange. Yet, social dependency also comes at a cost. Perceived social isolation, or loneliness, affects physical and mental health, cognitive performance, overall life expectancy, and increases vulnerability to Alzheimer's disease-related dementias. Despite severe consequences on behavior and health, the neural basis of loneliness remains elusive. Using the UK Biobank population imaging-genetics cohort (n = 40,000, aged 40-69 years when recruited, mean age = 54.9), we test for signatures of loneliness in grey matter morphology, intrinsic functional coupling, and fiber tract micro-structure. The loneliness-linked neurobiological profiles converge on a collection of brain regions known as the 'default network'. This higher associative network shows more consistent loneliness associations in grey matter volume than other cortical brain networks. Lonely individuals display stronger functional communication in the default network, and greater microstructural integrity of its fornix pathway. The findings fit with the possibility that the up-regulation of these neural circuits supports mentalizing, reminiscence and imagination to fill the social void.
... We also performed this assessment for the normalized functional scans, averaged across time (rmean = 0.86, SD = 0.03). Both assessments indicated a robust and consistent spatial normalization across scans, comparable to prior literature (Layden et al., 2017;Layden, Schertz, London, & Berman, 2019). We also assessed the temporal signal-to-noise ratio (tSNR) of the functional images and noted robust tSNR across scans (M = 56.36, ...
... We used a data-driven approach to investigate associations between rearing condition and brain-wide FC strength, measured using the ICC, which does not require arbitrary thresholding of functional connections (Martuzzi et al., 2011). ICC is computed at each brain voxel by averaging the squared Pearson correlations between a given voxel time series and every other voxel time series in the brain (Martuzzi et al., 2011); the voxel-wise distribution of ICC is then standardized (i.e., Z-scored) within each functional scan (Layden et al., 2017). ICC has previously proven effective for identifying functional hubs within the human brain associated Using an LME random intercept model, we regressed voxel-wise ICC onto age, rearing condition, an age by rearing condition interaction, isoflurane dose, body temperature, head coil, and a random intercept for bird. ...
... with a variety of affective, social, and cognitive phenomena (e.g.,Layden et al., 2017;Moreno- López, Sahakian, Manktelow, Menon, & Stamatakis, 2016;Vatansever, Manktelow, Sahakian, Menon, & Stamatakis, 2017). ...
Preprint
Much as humans acquire speech in early childhood, the zebra finch ( Taeniopygia guttata ) songbird learns to sing from an adult "tutor" during the first three months of life. Within a well-defined critical period (CP), juvenile zebra finches memorize a tutor song that will guide subsequent motor patterning. This sensory learning process is mediated by tutor experience-dependent neuroplasticity within the auditory forebrain. Here, we used longitudinal resting-state fMRI analyses to investigate whether tutor experience also modifies patterns of functional connectivity (FC) within the juvenile zebra finch brain. Eighteen male zebra finches (only males sing) were scanned before, during, and at the end of the CP, as well as at the young adult stage. Prior to the onset of the CP, birds were separated into rearing conditions: Normal (aviary-housed; N =5), Tutored (one adult male tutor and one adult female; N =7), and Isolate (two adult females, isolated from male song; N =6). Brain-wide voxel-wise analyses identified a single cluster overlapping the left caudomedial nidopallium (NCM) of the auditory forebrain that showed developmentally decreasing FC strength in Isolates but stable or increasing FC in Normal and Tutored birds. Additionally, FC between left NCM and left dorsal cerebellum showed a parallel developmental difference. Developmental changes in left NCM FC strength statistically mediated condition-related differences in song stereotypy. These results extend previous reports of tutor experience-dependent plasticity in NCM at epigenetic, genomic, molecular, and cellular levels to the whole-brain functional network level by demonstrating that tutor experience also influences the development of NCM FC. Moreover, these results link NCM FC to the emergence of song stereotypy.
... Next, we conducted seed-to-voxel (S2V) analyses, in which FC is quantified between a cluster of voxels that serve as a "seed" region and voxels distributed throughout the rest of the brain. S2V analyses have proven to be an effective method for identifying the specific local connections that underlie ICC or FC strength findings (Layden et al., 2017). ...
... We also performed this assessment for the normalized functional scans, averaged across time (r mean = 0.86, SD = 0.03). Both assessments indicated a robust and consistent spatial normalization across scans, comparable to prior literature (Layden et al., 2019(Layden et al., , 2017. We also assessed the temporal signal-to-noise ratio (tSNR) of the functional images and noted robust tSNR across scans (M = 56.36, ...
... We used a data-driven approach to investigate associations between rearing condition and brain-wide FC strength, measured using the ICC, which does not require arbitrary thresholding of functional connections (Martuzzi et al., 2011). ICC is computed at each brain voxel by averaging the squared Pearson correlations between a given voxel time series and every other voxel time series in the brain (Martuzzi et al., 2011); the voxel-wise distribution of ICC is then standardized (i.e., Z-scored) within each functional scan (Layden et al., 2017). ICC has previously proven effective for identifying functional hubs within the human brain associated with a variety of affective, social, and cognitive phenomena (e.g., Layden et al., 2017;Moreno-López et al., 2016;Vatansever et al., 2017). ...
Article
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One of the central questions of neuroethology is how specialized brain areas communicate to form dynamic networks that support complex cognitive and behavioral processes. Developmental song learning in the male zebra finch songbird (Taeniopygia guttata) provides a unique window into the complex interplay among sensory, sensorimotor, and motor network nodes. The foundation of a young male's song structure is the sensory memory he forms during interactions with an adult "tutor." However, even in the absence of tutoring, juveniles produce a song-like behavior. Thus, by controlling a juvenile male's tutor exposure, we can examine how tutor experience affects distributed neural networks and how network properties predict behavior. Here, we used longitudinal, resting-state fMRI (rs-fMRI) functional connectivity (FC) and song analyses to examine known nodes of the song network, and to allow discovery of additional areas functionally related to song learning. We present three major novel findings. First, tutor deprivation significantly reduced the global FC strength of the caudomedial nidopallium (NCM) subregion of the auditory forebrain required for sensory song learning. Second, tutor deprivation resulted in reduced FC between NCM and cerebellar lobule VI, a region analogous to areas that regulate limbic, social, and language functions in humans. Third, NCM FC strength predicted song stereotypy and mediated the relationship between tutoring and stereotypy, thus completing the link between experience, neural network properties, and complex learned behavior.
... Besides, research is lacking that explores the effect of loneliness on cognitive functions among non-elderly adults with MDD, and it is thus inconclusive whether and how loneliness will affect WM function in younger populations. Moreover, no research has explicitly examined the effect of loneliness on WM-related activations or functional connectivity patterns in the CCN or the DMN, although very limited recent evidence suggests that loneliness showed differential relations with the DMN connectivity during affective processing in elderly MDD patients and in healthy controls [39], and that loneliness was positively associated with resting-state connectivity within the CCN in healthy young adults [40]. These findings offer tentative support for an association between loneliness and functions of the cognitive control (i.e. ...
... CCN) and affect-related (i.e. DMN) networks [39,40]. However, no direct evidence exists on the relationship between loneliness and neural network functioning during WM performance. ...
... The LPFC mask included bilateral superior, middle and inferior frontal gyri (BA8, 9,44,45,46,47). The parietal cortices mask included bilateral superior and inferior parietal lobule (BA7, 39,40). The SMA mask included bilateral supplemental motor area (BA6, 8,32). ...
Article
Loneliness affects up to 40% of middle-aged and older adults, and is closely associated with major depressive disorder (MDD). However, the relationship between loneliness and neural network functioning during executive cognitive processes, such as working memory, in MDD is still unclear. To address this gap, our study recruited 21 medicated MDD patients (mean age = 52.0 ± 5 years) and 24 matched healthy controls (HC) (mean age = 48.7 ± 6 years) who completed an n-back fMRI task. For behavioural performance, we observed no significant moderating effect of MDD or loneliness on the task condition effect. However, loneliness was positively associated, and MDD was negatively associated, with the functional connectivity between the inferior parietal cortex and the rostral dorsomedial prefrontal cortex (DMPFC) during task performance. Furthermore, an interactive effect of loneliness and MDD was observed on the functional connectivity between the supplementary motor area and the caudal DMPFC during the n-back task, with loneliness showing a positive relationship in the HC group but a negative relationship in the MDD group with the connectivity. Our results indicated that loneliness may be associated with altered neural regulatory functioning on self-referential processing and action control, which may further depend on the individual’s depressive state. These findings can form the theoretical basis for devising intervention programme aimed at improving the mental wellness of the healthy and depressed lonely individuals.
... Several resting-state functional connectivity studies reported that loneliness is associated with diverse networks involved in cognitive control, emotional processing, and social cognition (Feng, Wang, Li, & Xu, 2019;Nakagawa et al., 2015;Tian et al., 2014). In addition, studies also reported that loneliness associated with attentional, perceptual, and executive-related networks (Layden et al., 2017;Mwilambwe-Tshilobo et al., 2019;Tian et al., 2017). Thus, multiple and functionally distinct neural circuits may contribute to the subjective experience of social isolation, and these circuits may further be differentially activated as a function of individual differences. ...
... We first examine whether there was a main effect of loneliness within each age cohort, as the majority of loneliness neuroimaging studies included either only younger (e.g., J. T. Cacioppo et al., 2009;Feng et al., 2019;Kanai et al., 2012;Layden et al., 2017;Nakagawa et al., 2015;Tian et al., 2017b) or only older people (e.g., Lan et al., 2016; N. M. L. Wong et al., 2016). We conducted whole-brain voxel-wise two-sample t-test analyses separately for younger and older adults with loneliness levels (dichotomous, Low lonely group as reference group) as the independent variable of interest and controlling for sex. ...
... The most surprising result from this study, given the prior resting-state imaging studies (Feng et al., 2019;Layden et al., 2017;Mwilambwe-Tshilobo et al., 2019;Tian et al., 2017), was the absence of a main effect for loneliness, whether measured by global mean CBF or Notes. Two-way ANCOVA was conducted across loneliness groups with age (dichotomous, younger cohort as the reference group), UCLA Loneliness score (dichotomous, low loneliness as the reference group), age x loneliness interaction, and controlled for sex, separately for three regions from age effect on regional CBF among high lonely group (regional mean CBF was extracted from each region). ...
Article
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Loneliness is defined as the subjective feeling that one’s social needs are not satisfied by both quantity and quality of one’s social relationships. Loneliness has been linked to a broad range of adverse physical and mental health consequences. There is an interest in identifying the neural and molecular processes by which loneliness adversely affects health. Prior imaging studies reported divergent networks involved in cognitive, emotional, and social processes associated with loneliness. Although loneliness is common among both younger and older adults, it is experienced differently across the lifespan and has different antecedents and consequences. The current study measured regional cerebral blood flow (CBF) using pulsed arterial spin labeling imaging. Forty-five older (Mage = 63.4) and forty four younger adults (Mage = 20.9) with comparable degrees of loneliness were included. Whole-brain voxel-wise analysis revealed a main effect of age (in superior temporal and supramarginal gyri), but no main effect of loneliness. Furthermore, the age effect was only observed among people who reported higher level of loneliness. These regions have previously been implicated in social- and attention-related functions. The moderation of loneliness on age and regional CBF suggests that younger and older individuals present differential neural manifestations in response to loneliness, even with comparable levels of loneliness.
... Humans will actively seek out social interactions to meet belongingness needs and if these inborn belongingness needs are either threatened or left unfulfilled, one's health and well-being may deteriorate (Baumeister & Leary, 1995;Lodder, Scholte, Goossens, Engels & Verhagen, 2015). While failure to fulfill the need to belong is associated with negative physical and psychological outcomes for the individual, threats to belongingness needs precipitate emotional distress that serves to motivate the individual to seek to have those needs met (Layden et al., 2017;Lodder et al., 2015). ...
... SMT posits that there is a psychological system that monitors one's social environment to detect change in one's relational value and self-esteem is that sociometer (Leary, 2005). Maintaining relational value impacts individuals' daily lives and is associated with several benefits, such as improved physical and mental health (Kashdan et al., 2014) just as there are negative consequences associated with decreases in relational value that result in drops in self-esteem, such as difficulty in reproductive tasks (Caccioppo & Caccioppo, 2014), emotional disturbances (Kashdan et al., 2014;Layden et al., 2017), negatively perceived social behavior (Clerkin, Smith & Hames, 2013;Lodder, Scholte, Goossens, Engels & Verhagen, 2016), dementia (Holwerda, Deeg, Beekman, Tilburg, Stek, Jonker & Schoevers, 2014), and premature death (Brown et al., 2015;Holt-Lunstad, Smith, Baker, Harris & Stephenson, 2015;Leary, 2005;Tyler & Branch, 2015). ...
... Thwarted needs. While failure to fulfill the need to belong is associated with negative physical and psychological outcomes for the individual, threats to belongingness needs precipitate emotional distress that serves to motivate the individual to seek to have those needs met (Caccioppo & Caccioppo, 2014;Holt-Lunstad et al., 2015;Kashdan et al., 2014;Layden et al., 2017;Lodder et al., 2015). Negative social experiences such as failure, rejection or embarrassment may threaten belongingness needs (Brown et al., 2015;Kashdan et al., 2014;Leary, 2005). ...
Thesis
The present study explored the role of binge drinking as a conformity behavior as it related to self-esteem and social acceptance in young adults. The purpose of this qualitative phenomenological study was to extend upon the current empirical understanding of Sociometer Theory (SMT) through an exploration the portion of the sociometer that operates within conscious awareness. The researcher gathered information regarding the lived experience of young adults’ engagement in binge drinking in attempts to increase self-esteem and social acceptance. A purposive sample of five female young adults between the ages of 22-24 years old experiencing thwarted belongingness, low relational self-esteem and external motives for alcohol consumption was selected. Data was collected via face-to-face, semi-structured interviews that were then transcribed, member-checked, and analyzed according to IPA methodology. The participants’ descriptions of their lived experiences resulted in 13 themes: low self-esteem was associated with behavior, specifically, low self-esteem was associated with and led to binge drinking; low relational value was associated with binge drinking; there was a conscious awareness of the relationship between self-esteem and relational value; and there was a conscious awareness of the cognitive processes regarding attempts to increase self-esteem. This served to increase the understanding of the portion of the sociometer that operates within conscious awareness. The findings of the present study have expanded upon the existing research regarding the role of binge drinking as a conformity behavior as it impacted self-esteem and social acceptance in attempts to increase one’s relational value in young adults. In addition to theoretical contribution, the results of this study extended to practical applications in the field of mental health and substance abuse treatment to assist in developing prevention and interventions to help prevent the engagement in binge drinking for conformity purposes.
... Prior studies have used rs-fMRI to characterize intrinsic functional brain networks related to loneliness and MIL. Greater feelings of loneliness have been associated with less integrated connectivity between attention networks (Tian et al., 2017), as well as increased RSFC within the cingulo-opercular network, which is implicated in cognitive control (Layden et al., 2017). These intrinsic changes are consistent with behavioral reports of associations between hyper-vigilance and loneliness (Cacioppo et al., 2016). ...
... The evolutionary theory of loneliness posits that feeling lonely is an aversive biological signal that motivates the individual to repair or seek new social relationships, and leads to neural changes that impact attention and processing of social information (Cacioppo and Cacioppo, 2018). While our findings are in accordance with previous studies linking loneliness with altered RSFC in networks related to attention and executive control (Layden et al., 2017), the results point to broader changes in brain connectivity across multiple networks. As with MIL, the most robust associations were observed for between network interactions, and specifically between the DN and FPN as well as networks implicated in more externallydirected cognition including attentional (e.g. ...
... Further, the DN has been implicated in low mood and ruminative thoughts (DuPre and Spreng, 2018), which may be elevated by a sense of loneliness. However, several methodological considerations may account for differences between Layden et al. (2017) and the current findings. While a whole-brain analytic approach was used in both, we examined connectivity strength using individually-parcellated neurocognitive networks-thereby accounting for inter-subject functional connectivity variability-rather than focusing on standardized network parcellation schemes. ...
Article
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Social relationships imbue life with meaning, whereas loneliness diminishes one's sense of meaning in life. Yet the extent of interdependence between these psychological constructs remains poorly understood. We took a multivariate network approach to examine resting-state fMRI functional connectivity's association with loneliness and meaning in a large cohort of adults (N = 942). Loneliness and meaning in life were negatively correlated with one another. In their relationship with individually parcelled whole-brain measures of functional connectivity, a significant and reliable pattern was observed. Greater loneliness was associated with dense, and less modular, connections between default, frontoparietal, attention and perceptual networks. A greater sense of life meaning was associated with increased, and more modular, connectivity between default and limbic networks. Low loneliness was associated with more modular brain connectivity, and lower life meaning was associated with higher between-network connectivity. These findings advance our understanding of loneliness and life meaning as distinct, yet interdependent, features of sociality. The results highlight a potential role of the default network as a central hub, providing a putative neural mechanism for shifting between feelings of isolation and purpose.
... Moreover, functional MRI (fMRI) studies also demonstrated that loneliness is associated with differences in brain activation [13][14][15] . However, although many studies show that loneliness is correlated with brain structures and functions [8][9][10][11][12][13][14][15][16] , limited studies have been performed on the resting-state functional connectivity related to loneliness [17][18][19][20] . Applying functional connectivity analysis during a resting state can reveal brain intrinsic organization and information processing 21 . ...
... Both studies by Layden et al. and Tian et al. in 2017 support the attentional bias of hypervigilance. Increased functional connectivity among cinguloopercular network areas, such as inferior frontal gyrus (IFG) and supplementary motor area (SMA) 17 , and lower causal flow of dorsal to ventral attention network, such as superior parietal lobule (SPL) to IFG 20 , may contribute to the increased social monitoring for potential social threat. However, despite supporting the theory, those previous studies have a limited sample size, which is less than a hundred. ...
... The mentioned brain areas play a role in visual attention [28][29][30] and social functioning 26,27 respectively. These results are expected due to the previous studies 6,14,15 and the neural finding of the previous resting-state functional connectivity study [17][18][19][20] suggesting that loneliness is associated with increased monitoring and inappropriate social behavior. This study is a conceptual replication in a large sample to confirm the functional connectivity related to visual attention and social brain areas. ...
Article
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Although loneliness itself is a natural emotion, prolonged loneliness is detrimental to human health. Despite its detrimental effect, few loneliness-related neuroimaging studies have been published and some have limitations on the sample size number. This study aims to find the difference in resting-state functional connectivity associated with loneliness within a big sample size via the seed-based approach. Functional connectivity analysis was performed on a large cohort of young adults (N = 1336) using the seed-based functional connectivity approach to address the concern from previous studies. The analysis yielded statistically significant positive correlations between loneliness and functional connectivities between the inferior frontal gyrus and supplementary motor area, precentral gyrus, and superior parietal lobule. Additionally, the analysis replicated a finding from a previous study, which is increased functional connectivities between the inferior frontal gyrus and supplementary motor area. In conclusion, greater loneliness is reflected by stronger functional connectivity of the visual attention brain area.
... Lastly, altered gray matter volume in the prefrontal system [e.g. dorsolateral prefrontal cortex (dlPFC)] (Kong et al., 2015) as well as its within-and betweennetwork organizations have been associated with diminished self-regulation in lonely people (Tian et al., 2014;Layden et al., 2017;Tian et al., 2017). Taken together, previous neuroimaging evidence indicates diverse manifestations of loneliness in multiple neuropsychological processes Cacioppo et al., 2014). ...
... The RSFC allows for examining interplay between large-scale neural systems associated with loneliness (Braun et al., 2018), which is a complex construct rooted in the functional and structural integrity of distributed networks (e.g. Tian et al., 2014;Nakagawa et al., 2015;Layden et al., 2017;Smith et al., 2017;Tian et al., 2017;Smith et al., 2018). Furthermore, the machinelearning approach typically implements cross-validation procedures to estimate the model with training samples and to test the performance of the model with independent samples (i.e. ...
... Accordingly, the current findings provide a potential neural mechanism on the impaired self-regulation and cognitive functions among lonely people (Baumeister et al., 2005;Campbell et al., 2006;Hawkley et al., 2009). In line with our findings, loneliness has been found related to changes in brain structures of the dlPFC (Kong et al., 2015) and its functional connectivity with arousal systems (Layden et al., 2017). ...
Article
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Loneliness is an increasingly prevalent condition linking with enhanced morbidity and premature mortality. Despite recent proposal on medicalization of loneliness, so far no effort has been made to establish a model capable of predicting loneliness at the individual level. Here, we applied a machine-learning approach to decode loneliness from whole-brain resting-state functional connectivity (RSFC). The relationship between whole-brain RSFC and loneliness was examined in a linear predictive model. The results revealed that individual loneliness could be predicted by within- and between-network connectivity of prefrontal, limbic and temporal systems, which are involved in cognitive control, emotional processing and social perceptions and communications, respectively. Key nodes that contributed to the prediction model comprised regions previously implicated in loneliness, including the dorsolateral prefrontal cortex, lateral orbital frontal cortex, ventromedial prefrontal cortex, caudate, amygdala and temporal regions. Our findings also demonstrated that both loneliness and associated neural substrates are modulated by levels of neuroticism and extraversion. The current data-driven approach provides the first evidence on the predictive brain features of loneliness based on organizations of intrinsic brain networks. Our work represents initial efforts in the direction of making individualized prediction of loneliness that could be useful for diagnosis, prognosis and treatment.
... Investigations reported an association of loneliness with poorer connectivity of white matter tracts between the nodes of ventral attentional network [29] as well as differential activation of TPJ, a node in ventral attentional network. Loneliness was also linked to a weaker relationship between dorsal and ventral attentional networks indicating decreased ability to filter less relevant stimuli [39], as well as increased functional connectivity in brain regions associated with cinguloopercular network [37]. ...
... Attentional networks are responsible for effortful versus environmental, stimulus-driven control of attention, and are localized to distinct anatomical areas with specific cognitive functions [80]. Four publications reported that loneliness was associated with differences in ventral attentional (including TPJ), dorsal attentional, and cingulo-opercular networks, in terms of functional and effective connectivity [29,37,39,43]. Attentional networks may be linked to hypervigilance and stress reactivity that are putatively involved in loneliness. ...
Article
Loneliness is associated with increased morbidity and mortality. Deeper understanding of neurobiological mechanisms underlying loneliness is needed to identify potential intervention targets. We did not find any systematic review of neurobiology of loneliness. Using MEDLINE and PsycINFO online databases, we conducted a search for peer-reviewed publications examining loneliness and neurobiology. We identified 41 studies (n = 16,771 participants) that had employed various methods including computer tomography (CT), structural magnetic resonance imaging (MRI), functional MRI (fMRI), electroencephalography (EEG), diffusion tensor imaging (DTI), single-photon emission computed tomography (SPECT), positron emission tomography (PET), and post-mortem brain tissue RNA analysis or pathological analysis. Our synthesis of the published findings shows abnormal structure (gray matter volume or white matter integrity) and/or activity (response to pleasant versus stressful images in social versus nonsocial contexts) in the prefrontal cortex (especially medial and dorsolateral), insula (particularly anterior), amygdala, hippocampus, and posterior superior temporal cortex. The findings related to ventral striatum and cerebellum were mixed. fMRI studies reported links between loneliness and differential activation of attentional networks, visual networks, and default mode network. Loneliness was also related to biological markers associated with Alzheimer’s disease (e.g., amyloid and tau burden). Although the published investigations have limitations, this review suggests relationships of loneliness with altered structure and function in specific brain regions and networks. We found a notable overlap in the regions involved in loneliness and compassion, the two personality traits that are inversely correlated in previous studies. We have offered recommendations for future research studies of neurobiology of loneliness.
... negative non-social) stimuli [92]. Importantly, the recent emphasis on the neuro-physiological correlates of loneliness [22] reflects its consequences on morbidity and mortality, over and beyond objective social isolation and health behaviors [93,94], and its adverse effects on neuro-cognitive functioning [95]. The present results might thus inform future research, and the assessment of possible interventions, on a borderline condition with considerable implications on individual and societal well-being. ...
... Based on the salience of negative social stimuli for a variety of neuro-psychiatric conditions [17,18], the present findings might represent a useful benchmark for assessing defective social cognition in pathological conditions, and/or its improvement with rehabilitative interventions focused on social skills. The possible extensions of the present study might also involve borderline conditions such as loneliness, which is nowadays acknowledged as a major risk factor for morbidity and mortality in elderly individuals, independent of objective social isolation and health behaviors ( [93,[95][96][97]). Studies using the cyberball paradigm have shown age-related effects of being neglected in social interactions [59], i.e. slowed self-initiated action and altered activity in the insular and anterior cingulate regions previously associated with social exclusion [98,99], particularly in elderly women. ...
Article
We have previously shown that activity and connectivity within and between the action observation and mentalizing brain systems reflect the degree of positive dimensions expressed by social interactions such as cooperativity and affectivity, respectively. Here we aim to extend this evidence by investigating the neural bases of processing negative dimensions of observed interactions, such as competition and affective conflict, possibly representing a benchmark for different pathological conditions. In this fMRI study 34 healthy participants were shown pictures depicting interactions characterized by two crossed dimensions, i.e. positively- vs. negatively- connotated social intentions mainly expressed in terms of motor acts vs. mental states, i.e. cooperative, competitive, affective and conflicting interactions. We confirmed the involvement of the action observation and mentalizing networks in processing intentions mainly expressed through motor acts (cooperative/competitive) vs. mental states (affective/conflicting), respectively. Results highlighted the selective role of the left pSTS/TPJ in decoding social interactions, even when compared with parallel actions by non-interacting individuals. Its right-hemispheric homologue displayed stronger responses to negative than positive social intentions, regardless of their motor/mental status, and decreased connectivity with the medial prefrontal cortex (mPFC) when processing negative interactions. The resulting mPFC downregulation by negative social scenes might reflect an adaptive response to socio-affective threats, via decreased mentalizing when facing negative social stimuli. This evidence on the brain mechanisms underlying the decoding of real complex interactions represents a baseline for assessing both the neural correlates of impaired social cognition, and the effects of rehabilitative treatments, in neuro-psychiatric diseases or borderline conditions such as loneliness.
... T. Cacioppo and Hawkley 2009;S. Cacioppo et al. 2016) and is associated with tonic alertness (Layden et al. 2017). Because features of loneliness, namely hypervigilance and tonic alertness, are also features of anxiety, we predicted that loneliness would likewise be associated with higher levels of SOR in individuals with ADHD. ...
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Compared to healthy controls (HCs), individuals with attention-deficit/hyperactivity disorder (ADHD) exhibit more symptoms of sensory processing disorder (SPD), which is associated with difficulties in educational and social activities. Most studies examining comorbid SPD-ADHD have been conducted with children and have not explored relations to brain volumes. In this pilot study, we assessed a subtype of SPD, sensory modulation disorder (SMD), and its relation to select brain volumes in adults with ADHD. We administered part of the Sensory Processing 3-Dimensions Scale (SP3D) to assess subtypes of SMD and collected structural imaging scans from 25 adults with ADHD and 29 healthy controls (HCs). Relative to HCs, subjects with ADHD scored higher on sensory craving (SC) and sensory under-responsivity (SUR) subscales. Although sensory over-responsivity (SOR) was marginally higher, this was no longer true when accounting for co-occurring anxiety. In individuals with ADHD, both SC and SUR were positively associated with amygdalar volume, SUR was also positively associated with striatal volume, whereas SOR was negatively associated with posterior ventral diencephalon volume. These preliminary findings suggest that SC and SUR may be characteristic of ADHD while SOR may be driven by co-occurring anxiety. Because different modalities were associated with different brain volumes, our findings also suggest that the modalities may involve unique neural circuits, but with a partial overlap between SC and SUR. These pilot data provide support for conducting studies examining SMD in larger samples of adults with ADHD to determine reproducibility, applicability and implications of these findings.
... In contrast, here it was lonely mood in particular that mediated the association between social distancing duration and reconstructive-and random-memory errors. We know that lonely mood leads to diminished executive control (e.g., Cacioppo, Ernst, et al., 2000;Layden et al., 2017). Given that source monitoring in memory retrieval is a form of executive control (Shimamura, 2002), participants' lonely mood may have impeded their source monitoring, which in turn led to memory errors. ...
... A = action observation; I = interaction; T = theory of mind (mentalizing) In the light of the centrality of social cognition in several neuropsychiatric disorders (DSM-5), characterizing the neural bases of this key ability of the social brain entails both scientific and translational implications. On the one hand, even in healthy young individuals the lack of interaction, that is, loneliness, has been shown to reflect in increased connectivity within the cingulo-opercular network associated with tonic alertness (Layden et al., 2017). Moreover, social cognitive functions can be disrupted in neurological (e.g., frontotemporal dementia or amyotrophic lateral sclerosis; Cerami et al., 2014aCerami et al., , 2014bCrespi et al., 2014Crespi et al., , 2016Crespi et al., , 2018, psychiatric (e.g., schizophrenia; Fujiwara, Yassin, & Murai, 2015) and developmental (e.g., autism; Fett, Shergill, & Krabbendam, 2015) disorders, as well as after acute brain damage (e.g., stroke or traumatic brain injury; ...
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While the action observation and mentalizing networks are considered to play complementary roles in understanding others' goals and intentions, they might be concurrently engaged when processing social interactions. We assessed this hypothesis via three activation‐likelihood‐estimation meta‐analyses of neuroimaging studies on the neural processing of: (a) social interactions, (b) individual actions by the action observation network, and (c) mental states by the mentalizing network. Conjunction analyses and direct comparisons unveiled overlapping and specific regions among the resulting maps. We report quantitative meta‐analytic evidence for a “social interaction network” including key nodes of the action observation and mentalizing networks. An action–social interaction‐mentalizing gradient of activity along the posterior temporal cortex highlighted a hierarchical processing of interactions, from visuomotor analyses decoding individual and shared intentions to in‐depth inferences on actors' intentional states. The medial prefrontal cortex, possibly in conjunction with the amygdala, might provide additional information concerning the affective valence of the interaction. This evidence suggests that the functional architecture underlying the neural processing of interactions involves the joint involvement of the action observation and mentalizing networks. These data might inform the design of rehabilitative treatments for social cognition disorders in pathological conditions, and the assessment of their outcome in randomized controlled trials.
... In contrast, here it was lonely mood in particular that mediated the association between social distancing duration and reconstructive-and random-memory errors. We know that lonely mood leads to diminished executive control (e.g., Cacioppo, Ernst, et al., 2000;Layden et al., 2017). Given that source monitoring in memory retrieval is a form of executive control (Shimamura, 2002), participants' lonely mood may have impeded their source monitoring, which in turn led to memory errors. ...
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In the absence of an effective vaccine or treatment, the current best defence against COVID-19 is social distancing—staying at home as much as possible, keeping distance from others, and avoiding large gatherings. Although social distancing maximizes physical health, we know little about its psychological consequences. In this research (N = 374), we investigated the effect of social distancing duration on negative moods and memory. The relation between social distancing duration and both negative mood and memory errors followed the same U-shaped function: negative moods and memory errors initially decreased steadily as social distancing duration increased, at which point (~ 30 days) they began to steadily increase. Subsequent analyses indicated that memory errors were mediated by lonely mood in particular. Thus, short-term social distancing might benefit psychological well-being and memory performance, but extended social distancing has the expected negative impact on mood and memory.
... Layden et al. found that loneliness in young adults was positively associated with increased functional connectivity in the supramarginal gyrus and central operculum. Interestingly, this was not explained by depressive symptoms, objective social isolation, and demographic variables [100]. An additional study examined connectivity in older adults with and without late-life depression [101]. ...
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PurposeLoneliness is increasingly recognised as the next critical public health issue. A plausible reason for this concern may be related to emerging societal trends affecting the way we relate, communicate, and function in our social environment. In 2006, a prominent review of the clinical significance of loneliness was published. However, there has not been a comprehensive update on known and emerging risk factors and correlates of loneliness since then. Furthermore, there is no conceptual model that has been developed to better account for the complexity of loneliness and to inform the development of evidence-based solutions as we challenge the issues of the twenty-first century.Methods We reviewed the current literature to identify either known or emerging risk factors and correlates of loneliness since 2006. This includes new or known evidence on: (1) demography; (2) health, including physical health; mental health; cognitive health; brain, biology, and genetics; and (3) socio-environmental factors including digital communication and the workplace.ResultsWe synthesized the literature according to a new proposed conceptual model of loneliness which showed the interplay between known and emerging correlates and risk factors from demography, health, to socio-environmental factors. In the conceptual model of loneliness, we illustrated how solutions can be delivered and tailored to an individual based on their life circumstances and preferences.Conclusion We concluded by making specific recommendations in advancing our scientific understanding of loneliness. Our knowledge can only be deepened if we increase scientific rigour via accounting for confounding variables and using longitudinal, multi-disciplinary, and multiple methodologies in research. We also call for the rigorous evaluation of programs targeting loneliness.
... 32 The prefrontal cortex is implicated in the perception of social isolation (i.e., loneliness). [33][34][35] The anterior cingulate cortex is functionally connected with the prefrontal cortex, with which it is associated with emotional and physiological adjustments for potential threats and stressors, and is known to be involved the social (rather than the physical) pain associated with loneliness. 36 The substantia nigra is best known for its role in reward and learning, which extends to social contexts as well. ...
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Humans are social animals that experience intense suffering when they perceive a lack of social connection. Modern societies are experiencing an epidemic of loneliness. While the experience of loneliness is universally human, some people report experiencing greater loneliness than others. Loneliness is more strongly associated with mortality than obesity, emphasizing the need to understand the nature of the relationship between loneliness and health. While it is intuitive that circumstantial factors such as marital status and age influence loneliness, there is also compelling evidence of a genetic predisposition towards loneliness. To better understand the genetic architecture of loneliness and its relationship with associated outcomes, we extended the genome-wide association study (GWAS) meta-analysis of loneliness to 511 280 subjects, and detect 19 significant genetic variants from 16 loci, including four novel loci, as well as 58 significantly associated genes. We investigated the genetic overlap with a wide range of physical and mental health traits by computing genetic correlations and by building loneliness polygenic scores in an independent sample of 18 498 individuals with electronic health record data to conduct a PheWAS with. A genetic predisposition towards loneliness was associated with cardiovascular, psychiatric, and metabolic disorders, and triglycerides and high-density lipoproteins. Mendelian randomization analyses showed evidence of a causal, increasing, effect of both BMI and body fat on loneliness. Our results provide a framework for future studies of the genetic basis of loneliness and its relationship to mental and physical health.
... Chantiluke et al., 2012). It is important to control for objective social isolation when investigating the effect of perceived loneliness or subjective social isolation (Layden et al., 2017). In the current study, we used exploratory factor analysis to capture the latent dimensions of executive control processes across ECF tasks and measures and examined the association of loneliness and those ECF components in older adults. ...
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Perceived loneliness has implications in both cognitive and affective domains. High loneliness is considered to be a major risk factor for major depressive disorder. Loneliness is also associated with impaired executive control functioning (ECF) including multiple cognitive subdomains, such as working memory, planning, response inhibition, and attention control. However, little knowledge exists as to whether perceived loneliness is associated with impaired functioning of specific ECF components. The relationship between perceived loneliness and the latent dimensions capturing multiple measures across different ECF paradigms has not been established. In this study, we first investigated the latent dimensions of ECF processes across a comprehensive range of paradigms using exploratory factor analysis. We then examined the association of perceived loneliness and the resulted ECF components in older adults while simultaneously controlling for other demographic and affective measures. Four components emerged from the factor analysis: social cognition and processing speed, planning and working memory, selective, divided attention and inhibition control, and sustained attention and motor inhibition. We observed that the second ECF component, planning and working memory, was a significant predictor of perceived loneliness even after controlling for depressive characteristics measured by the Geriatric Depression Scale. Our findings have potential clinical significance in the older population, by showing that planning and working memory functions may predict perceived loneliness, which is also associated with higher risk for major depression. Thus, older individuals who have lower planning and working memory functions may be specifically targeted for possible early prevention of chronic loneliness and depression.
... Furthermore, conflicting situation was associated with activation in the AI. Within social contexts, the AIdorsal ACC network has been associated with experiences of social exclusion and rejection (Eisenberger & Lieberman, 2004;Eisenberger, Lieberman, & Williams, 2003;Layden et al., 2017). Thus, the activation patterns in during social conflict in the current study are consistent with previous imaging studies on social exclusion and cognitive dissonance. ...
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Studies have shown that adolescents are more likely than adults to take risks in the presence of peers than when alone, and that young adolescents’ risk perception is more influenced by other teenagers than by adults. The current fMRI study investigated the effect of social influence on risk perception in female adolescents (aged 12–14) and adults (aged 23–29). Participants rated the riskiness of everyday situations and were then informed about the (alleged) risk ratings of a social influence group (teenagers or adults), before rating each situation again. The results showed that adolescents adjusted their ratings to conform with others more than adults did, and both age groups were influenced more by adults than by teenagers. When there was a conflict between the participants’ own risk ratings and the ratings of the social influence group, activation was increased in the posterior medial frontal cortex, dorsal cingulate cortex and inferior frontal gyrus in both age groups. In addition, there was greater activation during no-conflict situations in the right middle frontal gyrus and bilateral parietal cortex in adults compared with adolescents. These results suggest that there are behavioral and neural differences between adolescents and adults in conflict and no-conflict social situations.
... Consistent with this, limited evidence suggests that loneliness is linked with cerebellar functions. Higher loneliness levels were associated with increased resting-state functional connectivity between the cerebellum and the postcentral gyrus and insula, even when objective social isolation was controlled for (Layden et al. 2017). While evidence on cerebellar functional activations in associate with loneliness is lacking, a body of literature suggests that the level of cerebellar activities during affective processing, such as during performing the emotional stroop task, is altered in major depressive individuals (Fitzgerald et al. 2008;Mitterschiffthaler et al. 2008;Groenewold et al. 2013). ...
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Chronic loneliness predicts mood disturbances and onset of major depressive disorder. However, little research has examined the neural correlates of individual difference in susceptibility to perceiving loneliness. In addition, the role of cerebellum, which is heavily implicated in social, cognitive and affective processes, in loneliness is unclear. We studied 99 healthy individuals divided into susceptible, concordant and robust groups depending on whether the participant’s loneliness level was greater, comparable or less than her/his objective social isolation level. The cerebellar gray matter structure, functional activity and connectivity patterns during performing an emotion stroop task were examined. We found greater posterior and medial cerebellar volume in the susceptible group than the other groups. In addition, the posterior and medial cerebellar activities when processing positive versus neutral words exhibited significant interactive effects of both loneliness and social network, and susceptibility to isolation. Loneliness and social network also had positive effects on the right posterior cerebellar functional connectivity with the visual and premotor cortices. Our findings provide novel evidence on the intricate role of the cerebellum in loneliness and susceptibility to isolation, suggesting that socio-cognitive processes of the cerebellum in the hedonic domain may be a key mechanism underlying loneliness proneness.
... In recent years, promising evidence from animal models and intervention studies in humans indicates that e.g. the exposure to enriched environments show beneficial effects on structural and neurochemical measures within brain regions that are important for learning and memory such as the hippocampus 28,29,[31][32][33] . One can assume that brain regions that are sensitive to changes in environmental demands and social as well as cognitive stimulation are also more vulnerable to the negative consequences of prolonged loneliness, social disconnection and environmental deprivation [33][34][35][36] . ...
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Ample evidence indicates that loneliness in old age is associated with poor bodily and mental health. However, little is known about structural cerebral correlates of loneliness in healthy older adults. We examined such correlates in a magnetic resonance imaging (MRI) subsample of 319 older adults aged 61 to 82 years drawn from the Berlin Aging Study II. Using voxel-based morphometry (VBM) and structural equation modeling (SEM), latent hierarchical regression analyses were performed to examine associations of (i) loneliness, (ii) a range of covariates, and (iii) loneliness by covariate interactions with latent brain volume estimates of brain structures known to be involved in processing, expressing, and regulating emotions. Results from whole-brain VBM analyses showed that individuals with higher loneliness scores tended to have smaller gray matter volumes in three clusters comprising (i) the left amygdala/anterior hippocampus, (ii) the left posterior parahippocampus and (iii) the left cerebellum. Significant associations and interactions between loneliness and latent factors for the amygdala and the hippocampus were confirmed with a region-of-interest (ROI)-based approach. These findings suggest that individual differences in loneliness among older adults are correlated with individual differences in the volumes of brain regions that are central to cognitive processing and emotional regulation, also after correcting for confounders such as social network size. We discuss possible mechanisms underlying these associations and their implications.
... If a person feels lonely or rejected, or is stressed or sad, that negatively impacts inhibitory control, academic performance, and physical and mental health (evidence that loneliness impairs EFs and specifically inhibitory control [41][42][43], academic performance [20,44], and health [42,[45][46][47]; evidence that stress impairs EFs and specifically inhibitory control [48][49][50], academic performance [51][52][53], and health [54][55][56]; evidence that prolonged sadness impairs EFs and specifically inhibitory control [57][58][59], academic performance [60,61], and health [62][63][64][65]. Therefore, a reasonable prediction is that in a school program that promotes students working together and being kind to and supporting one another (i.e., prosocial behavior [66]) one should find less peer rejection, more joy in the classroom, less teacher burnout, and better student academic performance and inhibitory control. ...
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The kindergarten program, Tools of the Mind (Tools), has been shown to improve executive functions (as assessed by laboratory measures) and academic performance. The objective here was to see if Tools can improve executive functions in the real world (in the classroom), academic outcomes not previously investigated, reduce bullying and peer ostracism, and increase teachers' and students' joy in being in the classroom. This first randomized controlled trial of Tools in Canada included 351 kindergarten children (mean age 5.2 years at entry; 51% female) in 18 public schools. Stratified randomization resulted in teachers and students in both groups being closely matched. Teachers in both groups received the same number of training hours and same funds for new materials. Outcome measures were pre and post standardized academic skill assessments and teacher online survey responses. This study replicated that Tools improves reading and shows for the first time that it improves writing (far exceeding levels the school districts had seen before), self-control and attention-regulation in the real world (e.g., time on task without supervision), reduces teacher burnout and children being ostracized or excluded, and increases the joy students and teachers experience in school. By Spring, Tools teachers were still enthusiastic about teaching; control teachers were exhausted. These results were not only better than the control group but also better than Tools teachers experienced the year before Tools. Thus, children in a kindergarten curriculum that emphasized play, improving self-regulation, working together and helping one another, and hands-on learning performed better academically, showed less bullying and peer ostracism and more kindness and helping behavior than students in more traditional classes, and teacher enthusiasm for teaching soared. Tools reduced initial disparities separating children, schools, and teachers.
... Furthermore, in a large sample of 942 adults researchers found that individuals with higher levels of loneliness have less modular connections between specific brain networks, including the default, frontoparietal, attention, and perceptual networks [52 •]. In younger adults, loneliness was associated with greater functional connectivity between key node areas within the cingulo-opercular network, such as the insula and anterior cingulate cortex [51]. These studies suggest the possibility that brain regions important for processing emotion and reward and thinking about the self versus others may be impacted in younger adults who are lonely. ...
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Purpose of Review This narrative review highlights important factors contributing to loneliness in older adults prior to and during the COVID-19 pandemic and effects on brain health. Recent Findings We characterize risk factors for loneliness in older adulthood and the impact of COVID-19. Furthermore, we discuss the implications of loneliness for older adults’ brain health. Summary Understanding the multifactorial causes of loneliness in different subpopulations of older adults both before and during the COVID-19 pandemic will provide insights for the development of interventions targeted to reduce loneliness in older adults based on their specific risk factors.
... At the neurophysiological level, loneliness is associated with altered intrinsic functional connectivity (FC) in attentional (i.e. Dorsal and ventral networks) 24,25 and cognitive control networks (Cingulo-opercular network and right middle/superior frontal gyrus) 24,26 . Alterations in attentional and impulse control networks might hinder social adaptation through antisocial behavior 27 and the inability to accommodate contextual demands 28 . ...
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Social adaptation arises from the interaction between the individual and the social environment. However, there is little empirical evidence regarding the relationship between social contact and social adaptation. We propose that loneliness and social networks are key factors explaining social adaptation. Here we recruited 64 subjects to analyze the effects of loneliness, social network and their brain functional correlates on social adaptation. A hierarchical regression model confirmed that loneliness and social network have negative and positive effects on social adaptation respectively. Functional connectivity (FC) analysis showed that loneliness was associated with decreased FC between fronto-amygdalar and fronto-parietal regions, while the social network was positively associated with FC between the fronto-temporo-parietal network. Finally, a multidimensional path model examined the combined effects of behavioral and brain predictors of social adaptation. The model revealed that social networks mediated the effects of loneliness on social adaptation. Further, loneliness-related abnormal brain FC (associated with difficulties in cognitive control, emotion regulation, and sociocognitive processes) emerged as the strongest predictor of poor social adaptation. Findings offer insights into the brain indicators of social adaptation and highlight the role of social networks as a buffer against the maladaptive effects of loneliness. These findings may aid social development approaches.
... The study results revealed that lonely individuals differentiated the social threat images from nonsocial threat images more quickly in the early stages of information processing than non-lonely individuals (Cacioppo, Balogh, & Cacioppo, 2015). Greater feelings of loneliness were associated with increased resting-state functional connectivity in neural networks implicated in implicit attentional processing and tonic alertness (Layden et al., 2017). These findings are consistent with behavioral evidence of associations between hypervigilance and loneliness (Qualter et al., 2013;Cacioppo et al., 2014;Pickett, Gardner, & Knowles, 2004). ...
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Loneliness is a growing public health problem. Lonely individuals show a characteristic negative bias in the cognitive processing of socioemotional information. In the current study, we tested the effects of a novel computerized feedback-based interpretation training on socioemotional information processing. Lonely and non-lonely participants were assigned equally to training groups. During interpretation training, the promotion training group learned to associate subthreshold fearful and neutral expressions with socially more favorable labels than less favorable ones. The control training group learned to associate the same facial expressions with socially less favorable labels. After training, participants performed three socioemotional tasks. Results revealed that promotion training reduced associations between loneliness and recognition of anger and fear in lonely participants. In addition, compared to control training, promotion training significantly increased the likelihood of evaluating surprise expressions as positive rather than negative. This positive evaluation bias toward surprise faces increased in lonely participants with greater promotion learning. However, only non-lonely participants showed increased willingness to approach an unfamiliar female face after promotion training relative to control training. Despite this limitation, the findings demonstrate the potential of our novel feedback-based interpretation training in mitigating characteristic processing of socioemotional information among lonely people.
... impact mental health; threats precipitate emotional distress and drops in self-esteem that serve to motivate the individual to seek to have those needs met via conformity behaviors to increase chances for approval to increase relational value (Brown et al. 2015;Layden et al. 2017;Leary 2005;Lodder et al. 2016;Nikhila et al. 2016;Robinson et al. 2015Robinson et al. , 2016. ...
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The present study explored binge drinking as a conformity behavior as it related to self-esteem and social acceptance in young adults. The researcher gathered information regarding the lived experience of young adults’ engagement in binge drinking to increase self-esteem and social acceptance using a qualitative interpretative phenomenological approach (IPA). A purposive sample of five female college students aged 22–24 meeting the inclusion criteria via researcher-developed screening was recruited. Data was collected via face-to-face, semi-structured interviews that were then transcribed, member-checked, and analyzed according to the IPA methodology. Themes included the following: low self-esteem was associated with behavior, low self-esteem was associated with binge drinking, and low relational value was associated with binge drinking. These findings have expanded upon the existing research regarding the role of binge drinking as a conformity behavior as it impacted self-esteem and social acceptance in attempts to increase relational value in young adults.
... Neurally, brain networks underlying social-affective processing, attentive processing, and most recently the default mode network have been associated with loneliness (Cacioppo et al. 2009(Cacioppo et al. , 2016Kanai et al. 2012;Cacioppo, Capitanio, et al. 2014;Layden et al. 2017;Spreng et al. 2020). Across these studies, both task-related and resting state neural activities have been investigated. ...
Article
Loneliness and wisdom have opposing impacts on health and well-being, yet their neuro-cognitive bases have never been simultaneously investigated. In this study of 147 healthy human subjects sampled across the adult lifespan, we simultaneously studied the cognitive and neural correlates of loneliness and wisdom in the context of an emotion bias task. Aligned with the social threat framework of loneliness, we found that loneliness was associated with reduced speed of processing when angry emotional stimuli were presented to bias cognition. In contrast, we found that wisdom was associated with greater speed of processing when happy emotions biased cognition. Source models of electroencephalographic data showed that loneliness was specifically associated with enhanced angry stimulus-driven theta activity in the left transverse temporal region of interest, which is located in the area of the temporoparietal junction (TPJ), while wisdom was specifically related to increased TPJ theta activity during happy stimulus processing. Additionally, enhanced attentiveness to threatening stimuli for lonelier individuals was observed as greater beta activity in left superior parietal cortex, while wisdom significantly related to enhanced happy stimulus-evoked alpha activity in the left insula. Our results demonstrate emotion-context driven modulations in cognitive neural circuits by loneliness versus wisdom.
... Other studies examined the BOLD activity of the brain at rest through resting-state functional MRI and showed that social isolation and perceived loneliness were associated with increased activity in the right central operculum, right supramarginal gyrus and between default, frontoparietal, attention and perceptual networks (Layden et al., 2017;Mwilambwe-Tshilobo et al., 2019). Two studies found that higher loneliness scores were associated with (i) decreased blood flow from the dorsal to the ventral attentional network, (ii) decreased flow from the affective to the visual network and (iii) low-frequency fluctuations of the activity in the inferior temporal gyrus (Tian et al., 2017;Yi et al., 2018). ...
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According to the social brain hypothesis, the human brain includes a network designed for the processing of social information. This network includes several brain regions that elaborate social cues, interactions and contexts, i.e. prefrontal paracingulate and parietal cortices, amygdala, temporal lobes and the posterior superior temporal sulcus. While current literature suggests the importance of this network from both a psychological and evolutionary perspective, little is known about its neurobiological bases. Specifically, only a paucity of studies explored the neural underpinnings of constructs that are ascribed to the social brain network functioning, i.e. objective social isolation and perceived loneliness. As such, this review aimed to overview neuroimaging studies that investigated social isolation in healthy subjects. Social isolation correlated with both structural and functional alterations within the social brain network and in other regions that seem to support mentalising and social processes (i.e. hippocampus, insula, ventral striatum and cerebellum). However, results are mixed possibly due to the heterogeneity of methods and study design. Future neuroimaging studies with longitudinal designs are needed to measure the effect of social isolation in experimental v. control groups and to explore its relationship with perceived loneliness, ultimately helping to clarify the neural correlates of the social brain.
... Social isolation can impact the hippocampus through mechanisms similar to stress, where reduced glucocorticoid receptors (Kamal et al., 2014), disrupted neurogenesis (Cinini et al., 2014), and hippocampal volume shrinkage (Pereda-Perez et al., 2013) can result in learning and memory deficits. In addition to hippocampal impairments, social isolation can impact executive function, with poorer attentional regulation and hypersensitivity to negative social information (Cacioppo and Hawkley, 2009) and altered functional connectivity to frontal brain regions (Layden et al., 2017). Interestingly, there is also some evidence to support the exogenous administration of allopregnanolone (ALLO), a neurosteroid, in alleviating the symptoms of social isolation, with growing use of ALLO in treating post-traumatic stress disorder and traumatic brain injuries (Cacioppo and Cacioppo, 2015). ...
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Studies in rodents suggest that exposure to distinct spaceflight stressors (e.g., space radiation, isolation/confinement, microgravity) may have a profound impact on an astronaut's ability to perform both simple and complex tasks related to neurocognitive performance, central nervous system (CNS) and vestibular/sensorimotor function. However, limited information is currently available on how combined exposure to the spaceflight stressors will impact CNS-related neurocognitive and neurobiological function in flight and, as well, terrestrial risk of manifesting neurodegenerative conditions when astronauts return to earth. This information gap has significantly hindered our ability to realistically estimate spaceflight hazard risk to the CNS associated with deep space exploration. Notwithstanding a significant body of work with rodents, there have been very few direct investigations of the impact of these spaceflight stressors in combination and, to our knowledge, no such investigations using nonhuman primate (NHP) animal models. In view of the widely-recognized translational value of NHP data in advancing biomedical discoveries, this research deficiency limits our understanding regarding the impact of individual and combined spaceflight stressors on CNS-related neurobiological function. In this review, we address this knowledge gap by conducting a systematic and comprehensive evaluation of existing research on the impact of exposure to spaceflight stressors on NHP CNS-related function. This review is structured to: a) provide an overarching view of the past contributions of NHPs to spaceflight research as well as the strengths, limitations, and translational value of NHP research in its own right and within the existing context of NASA-relevant rodent research; b) highlight specific conclusions based on the published literature and areas needed for future endeavors; c) describe critical research gaps and priorities in NHP research to facilitate NASA's efforts to bridge the key knowledge gaps that currently exist in translating rodent data to humans; and d) provide a roadmap of recommendations for NASA regarding the availability, validity, strengths and limitations of various NHP models for future targeted research.
... To elicit effective prevention of cognitive decline, cognitive functioning has been studied in relation to parts or an aggregate of dimensions of social relationships, such as perceived isolation (or loneliness), social support, social network, social interaction, and social engagement (Griffin et al., 2020;Holwerda et al., 2014;Hughes et al., 2008;Lara et al., 2019;Layden et al., 2017;Poey et al., 2017;Saito et al., 2018;Shankar et al., 2013;Zunzunegui et al., 2003). While some research reported no association (Holwerda et al., 2014), most other previous findings suggest that poor social relationships are associated with increased risk of cognitive decline and/or impairment. ...
Article
Objectives: This study aimed to assess the relationship between social isolation and cognitive functioning. Method: Data were retrieved from the National Survey of the Japanese Elderly, a nationally representative sample of Japanese adults, aged 60 years or older. We estimated a social isolation index to incorporate variables, such as social interactions , social engagement, and social support, with perceived social isolation, for a comprehensive measurement. The association of social isolation with cognitive functioning was assessed using a panel data fixed-effects model, controlling for age, socioeconomic status, health-related variables, and time-invariant heterogeneity. Moreover, we conducted analyses using the System Generalized Method of Moments (GMM) to address the dynamic relationship of cognitive functioning and potential endogeneity. Results: For both men and women, the association between social isolation and cognitive functioning was significant, particularly among those aged 75 or older, as a 1% increase in social isolation was associated with decreased cognitive functioning (24% decrease for men and 20% decrease for women). However, this association was not confirmed by the System GMM, after addressing endogeneity. Discussion: Our findings potentially suggest that the association between social relationship and cognitive functioning reported in previous studies was biased, due to endogeneity. Although we did not observe causal impacts, this does not necessarily mean that social isolation does not have a negative impact on health, as both positive and negative consequences of social relationships may exist. Further research is needed to reveal the causal relationship, as well as the detailed mechanisms of health effects of social relationships.
... [20] Several whole-brain exploratory studies in socially isolated individuals have highlighted various changes in brain: 1. Large differences in the gray matter volume neuronal clusters in the anterior hippocampus, amygdala, and entorhinal/para-hippocampal regions in isolated individuals in the voxel-based morphometry studies [21] 2. Decreased gray matter volume in the left posterior superior temporal sulcus, middle temporal gyrus, and entorhinal cortex regions that are usually associated with associative memory, motion perception, and social awareness [21] 3. Decreased resting-state functional connectivity between several nodes of the anterior insula/ operculum, dorsal anterior cingulate cortex, and the superior frontal gyrus associated with diminished alertness, mood, and executive control on functional magnetic resonance imaging studies [22] 4. Weak activation of the mesolimbic dopamine system in isolated individuals suggesting decreased reward to social stimuli. In contrast, people that have a better social relationship tend to have a greater activation of the temporoparietal junction, dorsomedial prefrontal cortex, a region involved in cognition, information processing, and comprehension of language. ...
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Coronavirus disease 2019 pandemic spreads through inhalation of aerosols or droplets. Therefore, the use of face masks, alcohol-based sanitizers, and most importantly practicing quarantine/ isolation and social distancing are the main modalities for its prevention and control. Although isolation is essential, various psychological effects have been implicated with its practice in most of the age groups. Longstanding isolation and negligible interpersonal interactions can have changes in psychological processes and neurological and morphological changes in the brain. Morphological changes as seen through the neuroimaging studies include reduced volume of the structures involved in the synthesis of various nerve growth factors leading to impaired neurogenesis and subsequently psychological changes which can manifest as mood alterations such as anxiety, depression, feeling demoralized, obsessive thinking, and altered sleep–wake cycles besides others especially, in the vulnerable age groups such as children and the elderly. Although quarantine remains the cornerstone to contain the spread of the pandemic, its psychological impact run simultaneously, which should be, understood, and addressed to ameliorate its long-term impact.
... Increased amygdala activation may be related to attention to socially salient stimuli. For example, socially embedded individuals display stronger coupling of the limbic system with the cortical salience network (which includes the ACC and IC; Bressler and Menon, 2010), while lonely individuals show reduced functional connectivity between these networks (Layden et al., 2017). Oxytocin may be involved in strengthening this connectivity in socially enriched individuals, as OT administration enhances the functional coupling of the amygdala with the cortical salience network during positive social interactions (Rilling et al., 2018). ...
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In social species such as humans, non-human primates, and even many rodent species, social interaction and the maintenance of social bonds are necessary for mental and physical health and wellbeing. In humans, perceived isolation, or loneliness, is not only characterized by physical isolation from peers or loved ones, but also involves negative perceptions about social interactions and connectedness that reinforce the feelings of isolation and anxiety. As a complex behavioral state, it is no surprise that loneliness and isolation are associated with dysfunction within the ventral striatum and the limbic system – brain regions that regulate motivation and stress responsiveness, respectively. Accompanying these neural changes are physiological symptoms such as increased plasma and urinary cortisol levels and an increase in stress responsivity. Although studies using animal models are not perfectly analogous to the uniquely human state of loneliness, studies on the effects of social isolation in animals have observed similar physiological symptoms such as increased corticosterone, the rodent analog to human cortisol, and also display altered motivation, increased stress responsiveness, and dysregulation of the mesocortical dopamine and limbic systems. This review will discuss behavioral and neuropsychological components of loneliness in humans, social isolation in rodent models, and the neurochemical regulators of these behavioral phenotypes with a neuroanatomical focus on the corticostriatal and limbic systems. We will also discuss social loss as a unique form of social isolation, and the consequences of bond disruption on stress-related behavior and neurophysiology.
... Meng et al. reported a positive correlation between loneliness and alertness in college students in China, where a feeling of fear played a mediating role (45). In a study by Layden et al., loneliness was associated with increased resting state functional connectivity between several nodes involved in tonic alertness (46). In line with these findings, it can be assumed that the higher hyperarousal response to COVID-19 in our patients have led to greater feelings of loneliness. ...
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Objectives Although the COVID-19 pandemic has affected people all around the world, the elderly is at a higher risk of suffering from its consequences. One of the serious concerns is developing loneliness and post-traumatic stress symptoms, which may contribute to cognitive decline at older ages. This study aimed to examine the psychological responses and loneliness in elderly patients diagnosed with dementia. Methods Twenty-one patients diagnosed with dementia, with ages older than 40, and 19 caregivers were enrolled in the study. The patients have undergone a comprehensive neuropsychiatric interview and were assessed with De Jong Gierveld Scale for loneliness and Impact of Event Scale—Revised (IES-R). The severity of dementia was assessed by Functional Assessment Staging Tool (FAST Scale) and the Montreal Cognitive Assessment (MoCA). Results No significant difference was seen in patients and caregivers in the IES-R and loneliness scales. A higher level of avoidance and social and total loneliness were seen in higher FAST levels ( p -value: 0.046). There was a negatively significant correlation between MoCA score and avoidance. Hyperarousal was significantly correlated with emotional loneliness in patients. Conclusion We found a direct relationship between cognitive decline and the psychological impacts of COVID-19. Our results highlight the need for more comprehensive studies to further investigate the influence of the pandemic on the worsening of cognitive impairment and loneliness in patients with dementia.
Article
Social behavior varies across both individuals and species. Research to explain this variation falls under the purview of multiple disciplines, each with its own theoretical and empirical traditions. Integration of these disciplinary traditions is key to developing a holistic perspective. Here, we review research on the biology of social attachment, a phenomena in which individuals develop strong affective connections to one another. We provide a historical overview of research on social attachment from psychological, ethological and neurobiological perspectives. As a case study, we describe work on pair‐bonding in prairie voles, a socially monogamous rodent. This specific topic takes advantage of many biological perspectives and techniques to explain social bonds. Lastly, we conclude with an overview of multi‐dimensional conceptual frameworks that can be used to explain social phenomena, and we propose a new framework for research on individual variation in attachment behavior. These conceptual frameworks originate from philosophy, physics, ethology, cognitive science and neuroscience. The application and synthesis of such frameworks offers a rich opportunity to advance understanding of social behavior and its mechanisms. We review research on the biology of social attachment, a phenomena in which individuals develop strong affective connections to one another. We provide a historical overview of research on social attachment from psychological, ethological and neurobiological perspectives, and we provide an overview of multi‐dimensional frameworks to explain social phenomena. The application and synthesis of such frameworks offers a rich opportunity to advance understanding of social behavior and its mechanisms.
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Loneliness is strongly related to affective dysregulation. However, the neuropsychological mechanisms underpinning the loneliness-affective processing relationships remain unclear. Here, we first utilised the coordinate-based activation likelihood estimation method and confirmed functional clusters that are significantly related to loneliness includes striatum, superior and medial frontal gyrus, insula, and cuneus. Meta-analytic connectivity modelling was then performed to characterise the functional connectivity of these clusters across studies of emotion tasks. Our results revealed that these clusters co-activated with the cognitive control networks. From the literature, we understand that loneliness and its neural correlates are highly related to regulating the attention biases to social rewards and social cues. Therefore, the current meta-analysis provides proof-of-concept that loneliness up-regulates the cognitive control networks to process socio-affective information. Prolonged up-regulation thus exhausts cognitive resources and hence, affective dysregulation. This study offers insight into the intricate role of cognitive and affective regulation in loneliness and social perception. It provides meta-analytic evidence to support the cognitive control model of loneliness and loneliness-related affective dysregulation, bringing significant clinical implications.
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The multitude of terms associated with love has given rise to a false perception of love. In this paper, only maternal and romantic love are considered. Love is usually regarded as a feeling, motivation, addiction, passion, and, above all, an emotion. This confusion has consequences in the lives of human beings, leading not only to divorces, suicides, femicides but possibly also to a number of mental illnesses and suffering. Therefore, it is crucial to first clarify what is meant by emotion, motivation and love. This work aims to finally place love within the category of physiological motivations, such as hunger, thirst, sleep, or sex, on the basis that love is also essential for human survival, especially in childhood. Love is presented from an evolutionary perspective. Some other similarities between love and other physiological motivations are pointed out, such as its importance for appropriate human development, both its ontogeny and its permanence, and the long-lasting consequences of abuse and neglect. There are summarized reasons that account for this, such as the fact that physiological motivations are essential for survival and that love is an essential motivation for the survival of human offspring. Other reasons are that minimum changes in the quantity and quality of love alters development, that there can be a variety of neurophysiological and behavioural states within a motivation, and that motivations (also love) appear and change throughout development. Also, motivations and love sometimes may lead to an addictive behaviour. Finally, it is recognized that once physiological motivations (and love) appear, they become permanent. In a third section, some potential social, cultural, clinical and scientific consequences of the proposed consideration of love as a motivation are discussed. Accordingly, love’s recognition as a motivation in the clinical field would imply a better understanding of its disorders and its inclusion in classifications manuals such as The Diagnostic and Statistical Manual of Mental Disorders (DSM), or in the International Classification of Diseases (ICD). Considering love as a motivation rather than an emotion could also impact the results of scientific research (an example is included). A comprehensive understanding of these questions could potentially allow for a new therapeutic approach in the treatment of mental illness, while offering an all-inclusive evolutionary explanation of cultural phenomena such as the origin and diffusion of both language and art. Love should be understood as a physiological motivation, like hunger, sleep or sex, and not as an emotion as it is commonly considered.
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Wann haben Sie sich zuletzt verliebt? Wie häufig hatten Sie schon Liebeskummer? Hand aufs Herz: Über wen haben Sie sich in den vergangenen Wochen am meisten aufgeregt, über Ihren Freund/Ihre Freundin, einen Mitbewohner oder Ihre Eltern? Oder auch einen Dozenten, einen Sporttrainer oder einen Kommilitonen? Ob Liebes-, Arbeits-, Wohnbeziehung – soziale Beziehungen bestimmen unseren Alltag. Denn wir verbringen ihn mit Menschen, mit denen uns, ob gewollt oder nicht gewollt, Beziehungen verbinden: Wir haben Freunde, Verwandte, Vorgesetzte, Partner, manchmal auch Geliebte und zuweilen auch ein paar Feinde. In diesem Kapitel erfahren Sie, was Beziehungen unterschiedlicher Art aus sozialpsychologischer Sicht charakterisiert und welche Bedeutung Beziehungen für unser Wohlbefinden und unsere Gesundheit haben (Abschn. 1.1). Anschließend lesen Sie, welche Faktoren die Aufnahme einer Beziehung wahrscheinlicher machen (Abschn. 1.2). Sie lernen darüber hinaus die sozialpsychologische Sicht auf die Thematik „Liebe“ kennen sowie typische Verläufe von Paarbeziehungen, Forschung zum Umgang mit Krisen in der Partnerschaft und zu Auswirkungen von Trennungen (Abschn. 1.3).
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Background Perceived loneliness, an increasingly prevalent social issue, is closely associated with major depressive disorder (MDD). However, the neural mechanisms previously implicated in key cognitive and affective processes in loneliness and MDD still remain unclear. Such understanding is critical for delineating the psychobiological basis of the relationship between loneliness and MDD. Methods We isolated the unique and interactive cognitive and neural substrates of loneliness and MDD among 27 MDD patients (mean age = 51.85 years, 20 females), and 25 matched healthy controls (HCs; mean age = 48.72 years, 19 females). We assessed participants' behavioral performance and neural regional and network functions on a Stroop color-word task, and their resting-state neural connectivity. Results Behaviorally, we found greater incongruence-related accuracy cost in MDD patients, but reduced incongruence effect on reaction time in lonelier individuals. When performing the Stroop task, loneliness positively predicted prefrontal-anterior cingulate-parietal connectivity across all participants, whereas MDD patients showed a decrease in connectivity compared to controls. Furthermore, loneliness negatively predicted parietal and cerebellar activities in MDD patients, but positively predicted the same activities in HCs. During resting state, MDD patients showed reduced parietal-anterior cingulate connectivity, which again positively correlated with loneliness in this group. Conclusions We speculate the distinct neurocognitive profile of loneliness might indicate increase in both bottom-up attention and top-down executive control functions. However, the upregulated cognitive control processes in lonely individuals may eventually become exhausted, which may in turn predispose to MDD onset.
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Loneliness has a strong neurobiological basis reflected by its specific relationships with structural brain connectivity. Critically, affect traits are highly related to loneliness, which shows close association with the onset and severity of major depressive disorder. This diffusion imaging study was conducted on a sample of adolescent siblings to examine whether positive and negative affect traits were related to loneliness, with brain network efficiency playing a mediating role. The findings of this study confirmed that both global and average local efficiency negatively mediated the association between low positive affect and high negative affect and loneliness, and the mediation was more sensitive to sibling-shared affect traits. The findings have important implications for interventions targeted at reducing the detrimental impact of familiar negative emotional experiences and loneliness.
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Loneliness has been associated with detrimental effects on mental and physical health and is increasingly recognized as a critical public health issue which may be further exacerbated by societal challenges such as increasing urbanization, an aging society as well as the COVID-19 pandemic. We here review recent findings on the neurocognitive mechanisms and brain alterations that underpin social disconnectedness, therapeutic approaches for chronic loneliness and how these lines of research can be integrated to improve the efficacy of loneliness interventions in healthy individuals and patients with mental disorders.
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Inequalities in health outcomes impose substantial human and economic costs on all societies—and the relation between early adversity and lifelong well-being presents a rich scientific framework for fresh thinking about health promotion and disease prevention broadly, augmented by a deeper focus on how racism influences disparities more specifically. This review begins with an overview of advances in the biology of adversity and resilience through an early childhood lens, followed by an overview of the unique effects of racism on health and a selective review of findings from related intervention research. This article presents a framework for addressing multiple dimensions of the public health challenge—including institutional/structural racism, cultural racism, and interpersonal discrimination—and concludes with the compelling need to protect the developing brain and other biological systems from the physiological disruptions of toxic stress that can undermine the building blocks of optimal health and development in the early childhood period. Expected final online publication date for the Annual Review of Public Health, Volume 42 is April 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Social interaction complexity makes humans unique. But in times of social deprivation this strength risks to expose important vulnerabilities. Human social neuroscience studies have placed a premium on the default network (DN). In contrast, hippocampus (HC) subfields have been intensely studied in rodents and monkeys. To bridge these two literatures, we here quantified how DN subregions systematically co-vary with specific HC subfields in the context of subjective social isolation (i.e., loneliness). By co-decomposition using structural brain scans of ~40,000 UK Biobank participants, loneliness was specially linked to midline subregions in the uncovered DN patterns. These association cortex signatures coincided with concomitant HC patterns implicating especially CA1 and molecular layer. These patterns also showed a strong affiliation with the fornix white-matter tract and the nucleus accumbens. In addition, separable signatures of structural HC-DN co-variation had distinct associations with the genetic predisposition for loneliness at the population level.
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Although medial prefrontal cortex (mPFC) is known to play important roles in social behaviors, how early social experiences affect the mPFC and its subcortical circuit remains unclear. We report that mice singly housed (SH) for 8 weeks after weaning show a social recognition deficit, even after 4 weeks of resocialization. In SH mice, prefrontal infralimbic (IL) neurons projecting to the shell region of nucleus accumbens (NAcSh) show decreased excitability compared with group-housed (GH) mice. NAcSh-projecting IL neurons are activated when GH mice encounter a familiar conspecific, which is not observed in SH mice. Chemogenetic inhibition of NAcSh-projecting IL neurons in normal mice impairs social recognition without affecting social preference, whereas activation of these neurons reverses social recognition deficit in SH mice. Our findings demonstrate that early social experience critically affects mPFC IL-NAcSh projection, the activation of which is required for social recognition by encoding information for social familiarity.
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Problems with interpersonal relationships are often a chief complaint among those seeking psychiatric treatment; yet heterogeneity and homogeneity across disorders suggests both common and unique mechanisms of impaired interpersonal relationships. Basic science research has begun yielding insights into how the brain responds to social feedback. Understanding how these processes differ as a function of psychopathology can begin to inform the mechanisms that give rise to such interpersonal dysfunction, potentially helping to identify differential treatment targets. We reviewed 45 studies that measured the relationship between brain responses to social feedback and internalizing psychopathology. Depression was related to hyperreactivity of regions in the cingulo-opercular network to negative social feedback. Borderline personality disorder (BPD) was associated with hyperreactivity of regions in the default mode network to negative social feedback. The review also identified key insights into methodological limitations and potential future directions for the field.
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Background Individuals with internet gaming disorder (IGD) usually report a higher sense of loneliness. Although studies have suggested a key role of the prefrontal cortex-based resting-state functional connectivity (rsFC) in both IGD and loneliness, the potential mechanism between IGD and loneliness remains unclear. Methods Fifty-seven IGD and 81 matched recreational internet gamer users (RGU) underwent resting-state fMRI scans. The UCLA loneliness scale was used to measure loneliness. We first explored the brain areas that are both associated with loneliness and IGD severity. Then, the neuroimaging findings were extracted to test whether the rsFC of these brain regions moderates the relationship between IGD and loneliness. Results We observed reduced rsFC between the left dorsolateral prefrontal cortex (DLPFC) and the left precentral and the postcentral gyri and the supplementary motor area (SMA), which also correlated with increased IAT (Young’'s internet addiction test) scores. More importantly, the rsFC of the DLPFC-precentral gyrus and the DLPFC-postcentral gyrus moderated the relationship between IGD severity and loneliness scores. Additionally, we also found that the rsFC of the left DLPFC-precentral gyrus, the DLPFC-postcentral gyrus and the right DLPFC-SMA moderated the relationship between self-reported gaming craving and the UCLA scores. Conclusions The current study confirmed the role of the DLPFC in reward control (game craving) and emotion regulation (loneliness). Additionally, the rsFC of the prefrontal cortex-supplementary motor area moderates IGD and loneliness. These findings provide valuable understanding of the two-way relationship between IGD and loneliness.
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Bilaterally symmetric intrinsic brain activity (homotopic functional connectivity; FC) is a fundamental feature of the mammalian brain's functional architecture. In mammals, homotopic FC is primarily mediated by the corpus callosum (CC), a large interhemispheric white matter tract thought to balance the bilateral coordination and hemispheric specialization critical for many complex brain functions, including human language. The CC first emerged with the Eutherian (placental) mammals ∼160 MYA and is not found among other vertebrates. Despite this, other vertebrates also exhibit complex brain functions requiring hemispheric specialization and coordination. For example, the zebra finch (Taeniopygia guttata) songbird learns to sing from tutors much as humans acquire speech and must balance hemispheric specialization and coordination to successfully learn and produce song. We therefore tested whether the zebra finch also exhibits homotopic FC, despite lacking the CC. Resting-state fMRI analyses demonstrated widespread homotopic FC throughout the zebra finch brain across development, including within a network required for learned song that lacks direct interhemispheric structural connectivity. The presence of homotopic FC in a non-Eutherian suggests that ancestral pathways, potentially including indirect connectivity via the anterior commissure, are sufficient for maintaining a homotopic functional architecture, an insight with broad implications for understanding interhemispheric coordination across phylogeny.
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Background: Late-life depression (LLD) in the elderly was reported to present with emotion dysregulation accompanied by high perceived loneliness. Previous research has suggested that LLD is a disorder of connectivity and is associated with aberrant network properties. On the other hand, perceived loneliness is found to adversely affect the brain, but little is known about its neurobiological basis in LLD. The current study investigated the relationships between the structural connectivity, functional connectivity during affective processing, and perceived loneliness in LLD. Method: The current study included 54 participants aged >60 years of whom 31 were diagnosed with LLD. Diffusion tensor imaging (DTI) data and task-based functional magnetic resonance imaging (fMRI) data of an affective processing task were collected. Network-based statistics and graph theory techniques were applied, and the participants' perceived loneliness and depression level were measured. The affective processing task included viewing affective stimuli. Results: Structurally, a loneliness-related sub-network was identified across all subjects. Functionally, perceived loneliness was related to connectivity differently in LLD than that in controls when they were processing negative stimuli, with aberrant networking in subcortical area. Conclusions: Perceived loneliness was identified to have a unique role in relation to the negative affective processing in LLD at the functional brain connectional and network levels. The findings increas our understanding of LLD and provide initial evidence of the neurobiological mechanisms of loneliness in LLD. Loneliness might be a potential intervention target in depressive patients.
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According to the differential reactivity hypothesis, lonely individuals respond differently to their environment compared to nonlonely individuals, which may sustain their loneliness levels. However, this interesting hypothesis has not yet been explored in daily life: Do lonely individuals feel lonely all the time, or do they feel more or less lonely in specific social contexts? The main aim of the present study was to test the differential reactivity hypothesis in daily life by examining in three samples whether trait levels of loneliness affected the levels of state loneliness in different social contexts. We used baseline questionnaires to measure trait loneliness and the Experience Sampling Method to collect data on state loneliness, in early adolescents (N = 269, Mage = 14.49, 59% female) and late adolescents (N = 223, Mage = 19.60, 91% female) from the Netherlands and late adolescents from the United States (N = 126, Mage = 19.20, 51% female). Results provided evidence for the differential reactivity hypothesis in the total sample, as high lonely adolescents experienced higher levels of state loneliness in situations in which they were alone than low lonely adolescents, but also benefited more from being with intimate company than low lonely adolescents. In sum, the present study provided evidence for the differential reactivity hypothesis and showed that the experience of loneliness in daily life was remarkably similar across age and culture. Our findings provide important insights into the daily experiences of trait lonely people, which may provide starting points for interventions.
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Background: Depression and loneliness are prevalent and highly correlated phenomena among the elderly and influence both physical and mental health. Brain functional connectivity changes associated with depressive symptoms and loneliness are not fully understood. Methods: A cross-sectional functional MRI study was conducted among 85 non-demented male elders. Geriatric depression scale-short form and loneliness scale were used to evaluate the severity of depressive symptoms and loneliness, respectively. Whole brain voxel-wise resting-state functional connectivity density (FCD) mapping was performed to delineate short-range FCD (SFCD) and long-range FCD (LFCD). Regional correlations between depressive symptoms or loneliness and SFCD or LFCD were examined using general linear model, with age incorporated as a covariate and depressive symptoms and loneliness as predictors. Results: Positive correlations between depressive symptoms and LFCD were observed in left rectal gyrus, left superior frontal gyrus, right supraorbital gyrus, and left inferior temporal gyrus. Positive correlations between depressive symptoms and SFCD were observed in left middle frontal gyrus, left superior frontal gyrus, bilateral superior medial frontal gyrus, left inferior temporal gyrus, and left middle occipital region. Positive correlations between SFCD and loneliness were centered over bilateral lingual gyrus. Conclusion: Depressive symptoms are associated with FCD changes over frontal and temporal regions, which may involve the cognitive control, affective regulation, and default mode networks. Loneliness is associated with FCD changes in bilateral lingual gyri that are known to be important in social cognition. Depressive symptoms and loneliness may be associated with different brain regions in non-demented elderly male.
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Lonely individuals may exhibit dysfunction, particularly with respect to social empathy and self-efficacy. White matter (WM) structures related to loneliness have not yet been identified. We investigated the association between regional WM density (rWMD) using the UCLA Loneliness Scale in 776 healthy young students aged 18-27 years old. Loneliness scores were negatively correlated with rWMD in eight clusters: the bilateral inferior parietal lobule (IPL), right anterior insula (AI), posterior temporoparietal junction (pTPJ), left posterior superior temporal sulcus (pSTS), dorsomedial prefrontal cortex (dmPFC), and rostrolateral prefrontal cortex (RLPFC). The bilateral IPL, right AI, left pSTS, pTPJ, and RLPFC were strongly associated with Empathy Quotient (EQ), whereas the bilateral IPL, right AI, left pTPJ, and dmPFC were associated with General Self-Efficacy Scale (GSES) score. The neural correlates of loneliness comprise widespread reduction in WMD in areas related to self- and social cognition as well as areas associated with empathy and self-efficacy.
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Unlabelled: Early numerical proficiency lays the foundation for acquiring quantitative skills essential in today's technological society. Identification of cognitive and brain markers associated with long-term growth of children's basic numerical computation abilities is therefore of utmost importance. Previous attempts to relate brain structure and function to numerical competency have focused on behavioral measures from a single time point. Thus, little is known about the brain predictors of individual differences in growth trajectories of numerical abilities. Using a longitudinal design, with multimodal imaging and machine-learning algorithms, we investigated whether brain structure and intrinsic connectivity in early childhood are predictive of 6 year outcomes in numerical abilities spanning childhood and adolescence. Gray matter volume at age 8 in distributed brain regions, including the ventrotemporal occipital cortex (VTOC), the posterior parietal cortex, and the prefrontal cortex, predicted longitudinal gains in numerical, but not reading, abilities. Remarkably, intrinsic connectivity analysis revealed that the strength of functional coupling among these regions also predicted gains in numerical abilities, providing novel evidence for a network of brain regions that works in concert to promote numerical skill acquisition. VTOC connectivity with posterior parietal, anterior temporal, and dorsolateral prefrontal cortices emerged as the most extensive network predicting individual gains in numerical abilities. Crucially, behavioral measures of mathematics, IQ, working memory, and reading did not predict children's gains in numerical abilities. Our study identifies, for the first time, functional circuits in the human brain that scaffold the development of numerical skills, and highlights potential biomarkers for identifying children at risk for learning difficulties. Significance statement: Children show substantial individual differences in math abilities and ease of math learning. Early numerical abilities provide the foundation for future academic and professional success in an increasingly technological society. Understanding the early identification of poor math skills has therefore taken on great significance. This work provides important new insights into brain structure and connectivity measures that can predict longitudinal growth of children's math skills over a 6 year period, and may eventually aid in the early identification of children who might benefit from targeted interventions.
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Prior research has suggested that loneliness is associated with an implicit hypervigilance to social threats-an assumption in line with the evolutionary model of loneliness that indicates feeling socially isolated (or on the social perimeter) leads to increased attention and surveillance of the social world and an unwitting focus on self-preservation. Little is known, however, about the temporal dynamics for social threat (vs. nonsocial threat) in the lonely brains. We used high-density electrical neuroimaging and a behavioral task including social and nonsocial threat (and neutral) pictures to investigate the brain dynamics of implicit processing for social threat vs. nonsocial threat stimuli in lonely participants (N = 10), compared to nonlonely individuals (N = 9). The present study provides evidence that social threat images are differentiated from nonsocial threat stimuli more quickly in the lonely (~116 ms after stimulus onset) than nonlonely (~252 ms after stimulus onset) brains. That speed of threat processing in lonely individuals is in accord with the evolutionary model of loneliness. Brain source estimates expanded these results by suggesting that lonely (but not nonlonely) individuals showed early recruitment of brain areas involved in attention and self-representation.
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In 1978, when the Task Panel report to the U.S. President’s Commission on Mental Health emphasized the importance of improving health care and easing the pain of those suffering from emotional distress syndromes including loneliness, few anticipated that this issue would still need to be addressed 40 years later. In 2011, a meta-analysis on the efficacy of treatments to reduce loneliness identified a need for well-controlled randomized clinical trials focusing on the rehabilitation of maladaptive social cognition. We review assessments of loneliness and build on this meta-analysis to discuss the efficacy of various treatments for loneliness. With the advances made over the past 5 years in the identification of the psychobiological and pharmaceutical mechanisms associated with loneliness and maladaptive social cognition, there is increasing evidence for the potential efficacy of integrated interventions that combine (social) cognitive behavioral therapy with short-term adjunctive pharmacological treatments.
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Actual and perceived social isolation are both associated with increased risk for early mortality. In this meta-analytic review, our objective is to establish the overall and relative magnitude of social isolation and loneliness and to examine possible moderators. We conducted a literature search of studies (January 1980 to February 2014) using MEDLINE, CINAHL, PsycINFO, Social Work Abstracts, and Google Scholar. The included studies provided quantitative data on mortality as affected by loneliness, social isolation, or living alone. Across studies in which several possible confounds were statistically controlled for, the weighted average effect sizes were as follows: social isolation odds ratio (OR) = 1.29, loneliness OR = 1.26, and living alone OR = 1.32, corresponding to an average of 29%, 26%, and 32% increased likelihood of mortality, respectively. We found no differences between measures of objective and subjective social isolation. Results remain consistent across gender, length of follow-up, and world region, but initial health status has an influence on the findings. Results also differ across participant age, with social deficits being more predictive of death in samples with an average age younger than 65 years. Overall, the influence of both objective and subjective social isolation on risk for mortality is comparable with well-established risk factors for mortality. © The Author(s) 2015.
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Social isolation has been recognized as a major risk factor for morbidity and mortality in humans for more than a quarter century. The brain is the key organ of social connections and processes, however, and the same objective social relationship can be experienced as caring and protective or as exploitive and isolating. We review evidence that the perception of social isolation (i.e., loneliness) impacts brain and behavior and is a risk factor for broad-based morbidity and mortality. However, the causal role of loneliness on neural mechanisms and mortality is difficult to test conclusively in humans. Mechanistic animal studies provide a lens through which to evaluate the neurological effects of a member of a social species living chronically on the social perimeter. Experimental studies show that social isolation produces significant changes in brain structures and processes in adult social animals. These effects are not uniform across the brain or across species but instead are most evident in brain regions that reflect differences in the functional demands of solitary versus social living for a particular species. The human and animal literatures have developed independently, however, and significant gaps also exist. The current review underscores the importance of integrating human and animal research to delineate the mechanisms through which social relationships impact the brain, health, and well-being. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
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Social isolation has been recognized as a major risk factor for morbidity and mortality in humans for more than a quarter of a century. Although the focus of research has been on objective social roles and health behavior, the brain is the key organ for forming, monitoring, maintaining, repairing, and replacing salutary connections with others. Accordingly, population-based longitudinal research indicates that perceived social isolation (loneliness) is a risk factor for morbidity and mortality independent of objective social isolation and health behavior. Human and animal investigations of neuroendocrine stress mechanisms that may be involved suggest that (a) chronic social isolation increases the activation of the hypothalamic pituitary adrenocortical axis, and (b) these effects are more dependent on the disruption of a social bond between a significant pair than objective isolation per se. The relational factors and neuroendocrine, neurobiological, and genetic mechanisms that may contribute to the association between perceived isolation and mortality are reviewed. Expected final online publication date for the Annual Review of Psychology Volume 66 is November 30, 2014. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.
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