Loneliness, or the perceived discrepancy of ones relationships in terms of quality, is known as Perceived Social Isolation (PSI). Studies have shown that PSI is both increasing and is correlated with health risks. Specifically, PSI is not only related with risks of mortality but is also linked with variations in the brain. Having few social contacts, or being Objectively Socially Isolated (OSI) does not qualify as PSI. The aim of this thesis is to investigate the neural correlates of PSI, as distinguished from OSI. The true role of PSI is still unknown, however, arguments can be made that PSI serves an important role in survival. The social brain, which allows for social cognition is used as a basis for understanding PSI in this thesis. In this thesis, I found that individuals suffering from PSI have increased attention towards social threat, and a preference to engage in positive social stimuli. Further, PSI affects both social cognition and the social brain. However, regional brain activity was not confined to the social brain. The results showed that PSI may be related to both affective and attentional networks of the brain. PSI also affects activity in the ventral striatum. Further, PSI is related to varied regional brain size. I argue that PSI can be reduced by mainly fixing maladaptive cognitive patterns.

Feelings of social connection are important to maintain physical and psychological well-being. Perceived social isolation, or loneliness, is the subjective experience of feeling socially isolated and may be a direct threat to our health. During recent years, an increasing amount of people report high levels of loneliness, potentially brought on by the COVID-19 pandemic and its restrictions. Recent research suggests that the brain’s default mode network (DMN), a neural network active at wakeful rest, is related to these experiences. This paper aimed to systematically review alterations in the DMN in socially connected and lonely individuals. I searched PubMed and Scopus to find studies using self-report measures of social connection or loneliness, and functional or structural neuroimaging methods on healthy adults. Nine studies were included in this review. Generally, core regions of the DMN typically involved in episodic memory and self-referential processing showed increased activity in lonely individuals and decreased activity in socially connected individuals. These findings may reflect how lonely individuals ruminate about past social events while socially connected individuals attend less to the self. However, methodological heterogeneity between studieslimits the conclusions that can be drawn based on these results.

This dissertation contributes to research on social isolation in older adults aged 65 years and above through three essays that expand our understanding of the social determinants of health and identify the social and interpersonal factors that contribute to elderly wellbeing. This dissertation examines the significant factors contributing to the problem of social isolation, and how the availability of interest-based, low-cost engagement resources in the community can alleviate social isolation and foster healthy aging. Essay 1 is a systematic literature review with implications for future research that explores how technological skills and training based on user intention and availability of resources can alleviate social isolation. Essay 2 is a qualitative study that evaluates the effectiveness of a unique community-based senior exercise program in fostering social integration and in reducing social isolation. Essay 3 is a quantitative study that examines the magnitude and direction of the correlated relationships among the determinants of social inclusion and the impact of social and interpersonal processes on senior wellbeing. These three essays provide insight into the social isolation phenomenon that negatively impacts senior wellbeing and recommends solutions derived from a data driven examination of the problem that is especially applicable to economically disadvantaged senior communities. Moreover, this research provides community partners and gatekeepers a foundation for future research on the social isolation phenomenon and strategies for developing digital confidence and mobility program strategies that foster social inclusion and reduce social isolation for older adults.

Yes / Many governments including Malaysia imposed movement restrictions as public health measure to minimize COVID-19 (coronavirus) risks. Due to prolonged isolation, poorer physical and mental health is expected in the general population. Our aims were to examine (1) the mediating role of perceived social isolation (SI) and fear of social isolation (FSI) on the relationship between gratitude and anxiety, and (2) to explore the moderating role of age, education and socioeconomic status (SES) on the mediation model. A total of 427 participants currently living in Malaysia (Mage = 37.90, SD = 16.51, 313 females) completed a survey on isolation, gratitude and anxiety during a period of national lockdown. Results showed that that those with higher gratitude reported having less SI and FSI and less anxiety (Model 1). In Model 2 with age as moderator, young adults (YA) and middle-aged adults (MA) who had higher gratitude experienced lower SI and in turn had lowered anxiety, but such mediating role of SI was not observed among older adults (OA). As for FSI, MA who had higher gratitude had lower FSI and also lower anxiety but this relationship was not observed in YA or OA. We also examined the role of education and SES as moderators in the parallel mediation analysis. Results showed that the indirect association of gratitude with anxiety via FI and FSI was moderated by both education and SES. Specifically, among those with low education levels (regardless of SES), those with higher gratitude had lower SI and FSI which in turn reduced anxiety. This relationship is similar for those with medium level of education and from low and middle level of SES as well. Our findings highlight the importance of having some coping mechanism e.g., gratitude and social connection during the pandemic to have higher wellbeing and quality of life, especially for MA sample and people from low education and SES background. / This work was supported by Newton Fund Institutional Links grant ID: 331745333, under Newton-Ungku Omar Fund partnership to MHY. The grant is funded by the UK Department for Business, Energy and Industrial Strategy and Malaysian Industry-Government Group for High Technology (MIGHT) and delivered by the British Council. For further information, please visit www.newtonfund.ac.uk . The Newton Fund played no role in the planning and conceptualization of the manuscript, did not participate in the writing of the manuscript, and played no role in the decision to submit the manuscript.