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Date of Graduation

5-2026

Description

Adolescence is a period of transition from childhood to adulthood when people explore risky behaviors. Stressors during adolescence can change structural brain connectivity. Previous research has found weaker structural connectivity between reward circuits and future cognitive impairments among children raised in orphanages. Comparative research in mice suggests that social isolation after bullying can damage these connections and induce alcohol seeking. We tested whether social isolation was related to lower connectivity of targeted structural connections in adolescent humans. We analyzed data from the Adolescent Brain Cognitive Development study and found 130 subjects had experienced extreme social isolation. To evaluate the level of social isolation experienced by each subject, we averaged their scaled answers to questions regarding isolation and investigated the subjects two standard deviations above the mean. We predicted that social isolation would alter connectivity between reward circuits, which may lead to future risk seeking. The tracts that we studied included the uncinate fasciculus, a bundle of fibers connecting the prefrontal cortex to the amygdala, and the connection between the amygdala and nucleus accumbens. We characterized the structural connectivity between reward circuits in our group of subjects from MRI scans to evaluate our tracts of interest. We found that in socially isolated adolescents, there was impaired connectivity in the left uncinate fasciculus (p = 0.024) and abnormally stronger connectivity between the left amygdala and nucleus accumbens (p = 0.015). In order to evaluate what kind of effect social isolation and these connectivity impairments had on this group of adolescents, we predict that the group of isolated subjects will have behavioral differences like increased risk taking and substance use.

Publication Date

2026

Document Type

Book

Degree Name

Bachelor of Science in Biology

Degree Level

Undergraduate

Department

Biological Sciences

Advisor/Mentor

Leong, Josiah

Disciplines

Biology

Keywords

Natural Science

Social isolation predicts altered reward circuit connectivity and future behaviors in adolescents

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Biology Commons

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