Poster #38 - Nucleus Accumbens Activation Differs Across Sensation-seeking and Age.

• In Event: 2-163 - Poster Session 08
  In Poster Session: PS 08 Section - Cognitive Processes

Integrative Statement

Background: Adolescence is a developmental period that is marked by increased morbidity & mortality rates (Kann et al., 2016). Over the last decade, several models have emerged to inform the underpinning of neural and behavioral change (Shulman et al., 2016). These models have highlighted the importance of nucleus accumbens (NAcc) activation which is hypothesized to be associated with motivational (anticipation) and learning processes of salient cues (outcome), and peak sensation-seeking in mid to late adolescence (Steinberg et al., 2017; Lujitjen et al., 2017). Although one group has reported a moderating effect of age on the relation between NAcc activation to anticipatory reward cues and trait sensation-seeking, this relationship has been underexplored in reward outcome (Hawes et al., 2017). To our knowledge, no studies to date have analyzed the moderating effect of age on the relationship between self-reported sensation-seeking and NAcc activation on reward outcome on the Monetary Incentive Delay (MID) task.
Methods: The analytic sample is derived from the 1st wave (W1) of an ongoing longitudinal study characterizing neurocognitive correlates associated with engagement in health risk in mid to late adolescence. Sixty adolescents from Southeast Michigan completed a multiband functional MRI (fMRI) scan (M (SD) age: 18.6 (1.4) years; 55.9% female); however, neuroimaging is still underway, so the final sample is expected to be larger. During the fMRI, participants completed the MID task where they could win or lose money ($5, $0.20). They were instructed to pay attention to the shape that appeared on screen (2000ms; Random: Win $5 or $0.20, No Win or Lose, Don’t Lose $5 or $0.20, 100 trials total) and then respond using a trigger with their index finger when the same shape reappeared on the screen (1500 – 4000ms). To evaluate NAcc activation that was related only to winning trials, the feedback phase was modeled (1650ms). SPM MarsBaR was used to extract mean signal intensity for the MNI right & left NAcc region of interest. A trait sensation seeking score was used from W1 self-reported BSSS measure. Hierarchical multiple regression was used to investigate age, sensation seeking, and the sensation-seeking-by-age interaction as predictors of right NAcc & left NAcc activation (Table 1).
Results: In the final model, sensation-seeking was a significant predictor of right & left NAcc activation (p < .05). Age was a significant predictor only of right NAcc activation (p < .05). Further, age significantly moderated the relationship between sensation-seeking and left NAcc activation (p < .01) but was not significant for right NAcc activation (p = .06). Older adolescents who were low sensation-seekers had higher activation in left NAcc during reward outcome than younger adolescents that were low sensation-seekers (Figure 1). Indicating that the reward processes in the left NAcc among learning salient cues may differ by age among low sensation-seekers.
Conclusions: Findings highlight novel associations of the moderating effect of age on the relationship between sensation-seeking and reward activation in the NAcc. This effect may be important in considering differences among low, average and high sensation-seekers in learning/responding to salient outcomes.

Authors

• Michael Demidenko, Department of Psychology, University of Michigan
  Presenting Author

• Joshua R.B. Hatfield, Institute for Social Research, University of Michigan
  Non-Presenting Author

• Edward D. Huntley, Institute for Social Research, University of Michigan
  Non-Presenting Author

• Daniel Keating, University of Michigan
  Non-Presenting Author