Type
Text
Type
Dissertation
Advisor
Canli, Turhan | Kritzer, Mary | Evinger, L. Craig | Leung, Hoi-Chung.
Date
2015-12-01
Keywords
aging, emotion, fMRI, OXTR | Neurosciences
Department
Department of Neuroscience.
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/76576
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
Loneliness, defined as the subjective experience of social isolation, has been linked to poor health outcomes (e.g. depression, cardiovascular disease) and is prevalent among older adult populations. To improve upon current treatments, the interaction between genetic and environmental risk factors for loneliness and their effect on the brain must be better understood. The present study investigated the brain basis of loneliness in younger (mean age = 20.4) and older adults (mean age = 62.9). We used functional magnetic resonance imaging (fMRI) and an emotional picture task to address this question. fMRI data were collected on a 3T Siemens Trio Scanner, with functional whole-brain images acquired using a gradient echo T2*-weighted EPI scan (TR = 2.5 s; TE = 30 ms; flip angle = 90; FOV = 256mm). 99 subjects (49 older, 50 younger) viewed pleasant and unpleasant social and non-social images in the scanner followed by completion of questionnaires including an objective measure of loneliness, the Social Network Index, and a subjective measure of loneliness, the UCLA loneliness scale. Saliva samples were collected for genotyping analysis of single nucleotide polymorphisms (SNPs) in the oxytocin receptor gene (OXTR) that are associated with pair bonding and social behaviors. Questionnaire results indicated that older adults were significantly less lonely, anxious, shy, and depressed and had more frequent social contacts compared to younger adults. Eye tracking data demonstrated that older adults spent significantly more dwell time on faces while viewing both pleasant and unpleasant social images. Furthermore, older adults showed significantly greater activation in the fusiform gyrus during viewing of pleasant social images, even when controlling for differences in loneliness and gaze (p < 0.05, FWE corrected). These results support the positivity effect, which is a tendency among older adults to attend preferentially to positive information to increase their emotional satisfaction. Secondly, our genetic analyses demonstrated that individuals with the A/G genotype of the OXTR rs53576 SNP scored significantly higher on the shyness scale compared to G/G subjects (p < 0.005). Additionally, functional connectivity analyses indicated increased connectivity between the hypothalamus and a cluster in the limbic lobe for individuals with the rs53576A genotype during viewing of unpleasant social pictures. These results suggest that rs53576A individuals show a heightened response to negative social information. Taken together, our results highlight the influence of age, genetic polymorphisms and neural circuits on social behavior. | 100 pages
Recommended Citation
D'Agostino, Alexandra, "Age Differences in Loneliness: Neural Correlates, Neurogenetics and Functional Connectivity" (2015). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2470.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2470