Events Calendar

03 Mar
Brenden Tervo-Clemmens
Event Type

Defenses

Target Audience

Faculty, Graduate Students

University Unit
Department of Psychology
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Dissertation Defense-Brenden Tervo-Clemmens

Linking Striatal Dopamine and Decision-Making to Adolescent Risk-Taking

 

Adolescence is characterized by a peak in risk-taking behaviors that increases the likelihood of problematic substance use, sexually transmitted diseases, and fatal accidents. Prominent neurodevelopmental theories suggest these behaviors are driven by the maturation of the striatal dopamine (DA) system and its modulation of prefrontal-striatal circuitry. To date however, research in this area has been limited, both by an inability to assess DA systems in vivo in human adolescents and an incomplete understanding of the intermediate cognitive and affective processes linking striatal DA and risk-taking. This dissertation built upon a first-of-its kind longitudinal neuroimaging dataset (N=144) that collected direct and indirect measures of striatal DA, using positron emission tomography (PET) and brain-tissue iron imaging, respectively, resting-state functional connectivity data, field-standard risk-taking measures, and a validated developmentally sensitive decision-making task. To increase statistical power, an additional sample (N=187) with key overlapping measures was also examined. Across three aims, mixed support was found for the hypothesized integrative psychobiological model. Consistent with prior work, significant developmental differences were found in risk-taking propensity measures (evidence for both an adolescent peak and age-related decreases), in iron-based, indirect measures of striatal DA (age-related increases), and in model-based learning during the decision-making task (age-related increases). However, associations between risk-taking propensity measures and striatal DA measures were not statistically significant. Evidence was found for an association between indirect striatal DA measures and performance of the decision-making task, where those with higher striatal iron for their age displayed more habitual responding during early adolescence. There was also evidence that striatal iron measures were associated with frontostriatal connectivity. Nevertheless, broader circuit-level hypotheses of developmental changes in dopamine processing supporting changes in frontostriatal connectivity and subsequently risk-taking propensity were limited in this sample. Results suggest risk-taking may be related to striatal DA indirectly via decreased frontostriatal connectivity, although these associations were not developmentally sensitive in the current sample. These initial results establish testable hypotheses for larger developmental samples with more detailed phenotyping and expanded imaging metrics. Ultimately, future work can refine diverse neurodevelopmental pathways of adolescent risk-taking and contribute to biologically informed interventions for at-risk youth.

Dial-In Information

Please contact Graduate Administrator, Francesca Sirianni: frs38@pitt.edu, for Zoom link. 

Wednesday, March 3 at 10:00 a.m. to 12:00 p.m.

Virtual Event

Dissertation Defense-Brenden Tervo-Clemmens

Linking Striatal Dopamine and Decision-Making to Adolescent Risk-Taking

 

Adolescence is characterized by a peak in risk-taking behaviors that increases the likelihood of problematic substance use, sexually transmitted diseases, and fatal accidents. Prominent neurodevelopmental theories suggest these behaviors are driven by the maturation of the striatal dopamine (DA) system and its modulation of prefrontal-striatal circuitry. To date however, research in this area has been limited, both by an inability to assess DA systems in vivo in human adolescents and an incomplete understanding of the intermediate cognitive and affective processes linking striatal DA and risk-taking. This dissertation built upon a first-of-its kind longitudinal neuroimaging dataset (N=144) that collected direct and indirect measures of striatal DA, using positron emission tomography (PET) and brain-tissue iron imaging, respectively, resting-state functional connectivity data, field-standard risk-taking measures, and a validated developmentally sensitive decision-making task. To increase statistical power, an additional sample (N=187) with key overlapping measures was also examined. Across three aims, mixed support was found for the hypothesized integrative psychobiological model. Consistent with prior work, significant developmental differences were found in risk-taking propensity measures (evidence for both an adolescent peak and age-related decreases), in iron-based, indirect measures of striatal DA (age-related increases), and in model-based learning during the decision-making task (age-related increases). However, associations between risk-taking propensity measures and striatal DA measures were not statistically significant. Evidence was found for an association between indirect striatal DA measures and performance of the decision-making task, where those with higher striatal iron for their age displayed more habitual responding during early adolescence. There was also evidence that striatal iron measures were associated with frontostriatal connectivity. Nevertheless, broader circuit-level hypotheses of developmental changes in dopamine processing supporting changes in frontostriatal connectivity and subsequently risk-taking propensity were limited in this sample. Results suggest risk-taking may be related to striatal DA indirectly via decreased frontostriatal connectivity, although these associations were not developmentally sensitive in the current sample. These initial results establish testable hypotheses for larger developmental samples with more detailed phenotyping and expanded imaging metrics. Ultimately, future work can refine diverse neurodevelopmental pathways of adolescent risk-taking and contribute to biologically informed interventions for at-risk youth.

Dial-In Information

Please contact Graduate Administrator, Francesca Sirianni: frs38@pitt.edu, for Zoom link. 

Wednesday, March 3 at 10:00 a.m. to 12:00 p.m.

Virtual Event

Event Type

Defenses

Target Audience

Faculty, Graduate Students

University Unit
Department of Psychology