resolution=3.12x3.12 mm; slice thickness=4 mm. High resolution anatomical T1 scans were obtained for spatial normalization. Motion was minimized with foam pads and emphasis on importance of keeping still. Data analysis Demographic, psychometric and task measures. Independent t- or χ2-tests examined group differences. Response time (RT) and success rate for each incentive condition were calculated and found normally distributed (KS test, p’s>.17). Repeated-measures ANOVAs were conducted for RT and success rate, separately, assessing performance differences between groups: valence (win/loss) x amount ($0.20/$5). Post-hoc t-tests determined the source of any differences. Pearson’s correlations evaluated relationships between variables. Functional data preprocessing. Functional images were reconstructed using an iterative algorithm (, ). Data were motion corrected using FSL4.0 (Analysis Group, FMRIB, Oxford, UK) (). Runs exceeding 2 mm translation or 2° rotation were excluded. Image processing and statistical analysis used statistical parametric mapping (SPM2, Wellcome Institute of Cognitive Neurology, London, UK). Functional images were spatially normalized to standard stereotactic space as defined by the Montreal Neurological Institute. Images were spatially smoothed with a 6 kernel. Individual subject statistical maps. Individual analysis a general linear model (GLM) with five regressors of interest (for each incentive condition) convolved with the hemodynamic response function (HRF). Motion parameters were modeled as nuisance regressors. Contrasts for anticipation of reward ($0.2 and $5.0 combined) minus neutral and anticipation of loss (combined) minus neutral, were calculated.
reward anticipation, but actually positive, potentially representing significant inefficiencies between salience assignation and action. Furthermore, we found NAcc-SSMA connectivity correlated with sensation seeking in opposite directions as a function of family history, with higher sensation seeking associated with increasingly positive connectivity in FH+. Incentive-related connectivity mediated the relationship between this personality trait and DDU in at-risk subjects, suggesting that individual variations in neural connectivity, and not only single brain regions, influence the relationship between personality and outcome. The SSMA, encompassing the mesial portion of the superior frontal gyrus, paracentral lobule, cingulate gyrus and precuneus (), incorporates structures within both the attention and motor networks (). As such, it is involved in initiation and integration of motor function with visual sensory and emotional guidance, or an “urge to move” (, , ). The atypical reward-related coupling in high-risk subjects may reflect inefficient communication of incentive salience processed through the NAcc and linked with internal mentation through the precuneus and sensoriomotor regions. As PPI does not yield information regarding causal or directional relationships between functional coupled regions but infers context-driven changes in interregional correlations between structures, interpretation of our results is limited. In addition, as a developmental imbalance between control and reward regions in adolescents has been proposed to influence risky behaviors (), it was interesting that we did not find connectivity differences with executive/cognitive areas as initially hypothesized. These results do not rule out developmental differences based on familial risk. Indeed as competition between functional networks has been shown to mediate task performance (), this highlights the need for additional study to illuminate maturational trajectories of competing networks.