Sullwold, Kristin Marie2010-09-282010-09-282010-06https://hdl.handle.net/11299/94195University of Minnesota Ph.D. dissertation. June 2010. Major: Psychology. Advisor: Monica Luciana, PhD. 1 computer file (PDF); vi, 81 pages.Cognitive flexibility facilitates the ability to quickly change behavior to adjust to changing environmental contingencies by shifting attention away from one task and attending to another. This ability may be one of a number of executive functions that improves through childhood and into adulthood. This study was conducted to examine the development of task switching during adolescence. Specifically, the development of two cognitive processes, attention switching and processing speed, that may underlie task switching ability were examined within a single task. Additionally, the degree to which self-reported externalizing behavior impacts these aspects of task switching ability was investigated. Individuals (N = 177) ages 9 to 23 participated in the study. The results showed that the different cognitive components that underlie task switching ability develop at different rates. Attention switching ability appears to be mature by early adolescence; however, the ability to efficiently activate the upcoming task set, which is likely dependent on processing speed, continues to increase until mid-adolescence. There was limited evidence that externalizing behavior in a non-clinical sample impacts attention switching performance. Externalizing behavior does not appear to significantly influence processing speed. These data clarify the nature of task switching development in adolescence by revealing how age-related changes in two cognitive components that underlie task switching ability contribute to cognitive flexibility.en-USAdolescenceCognitive flexibilityExternalizingTask switchingPsychologyThesis or Dissertation