PROJECT SUMMARY Irritability during preschool is predictive of later developing psychopathology, however the mechanism conferring this increased risk is not well-understood. Discerning temperamental irritable behaviors from clinically-concerning irritability during the preschool years is complicated by the common and developmentally- expected occurrence of negative affect and temper tantrums during this age. A potential mechanism through which preschool irritability may confer risk for psychopathology is through shaping how children process emotional information—preschoolers are both developing a rich lexicon of emotional expression and the ability to label and interpret emotions in others. Further, there is evidence in adolescent and adult populations that clinical irritability is associated with disruptions in emotion processing. Thus, this project posits that how children process emotional information can further differentiate normative versus clinically-concerning irritability. Understanding irritability in the context of emotion processing during these critical foundational years would provide insight into the etiology of mood and disruptive disorders. Further, there is evidence that the co-occurrence of unprovoked aggression, noncompliance, and callous behavior can differentiate children who develop internalizing versus externalizing psychopathology. This project will characterize irritability behavior contextualized within these other symptoms and test if these co-occurring behaviors are associated with distinct emotion processing. In Aim 1, we test if specific activation or connectivity patterns during dynamic positive and negative emotional contexts shift across age. In Aim 2, we test if 1) the individual differences in this emotional processing map to irritability behaviors and 2) if they are further differentiated by co-occurring aggression, noncompliance, or callous behaviors. During this process, the candidate will gain valuable skills in fMRI network analyses, clinical neuroscience, and written and oral presentation of this work. This valuable study will not only significantly add to our understanding of foundation emotional development in preschool—an area of study that lacks a strong neuroscientific understanding as of now—but also add to our ability to understand risk and resilience to psychopathology during a plastic period in development. Altogether, this project will help the candidate accomplish her goal of becoming an independent principle investigator at a research university significantly contributing to mapping affective neurodevelopmental risk for psychopathology.