This dissertation study aimed to explore whether and how individual differences in verbal and visuospatial working memory capacity and executive functions influence elementary students' mathematics fact mastery and mathematics anxiety as they engage in learning using ReflexTM, a game-based, visuospatial rich adaptive learning platform for practicing mathematics facts. A within-subjects, pretest-posttest research design was employed to investigate how individual differences in verbal and visuospatial working memory capacity, inhibitory control, and set shifting influence student mathematics fact mastery and mathematics anxiety in ReflexTM. Forty second-graders played ReflexTM mathematics fact games for one semester as part of their established curriculum. Individual differences in verbal and visuospatial working memory, inhibitory control and set shifting were measured using age-appropriate cognitive tests. Students self-reported their mathematics anxiety. Mathematics performance was assessed within ReflexTM and using a conventional paper-and-pencil mathematics assessment in the beginning and at the end of the semester. Additionally, a combined measure of mathematics anxiety and performance was calculated to reflect each student's anxiety-performance efficiency.Results indicated that, when compared with other individual differences, visuospatial working memory capacity played a more significant role in influencing student mathematics fact mastery and mathematics anxiety in this visuospatial adaptive learning platform. Specifically, children with high visuospatial working memory capacity achieved higher in ReflexTM mathematics test scores and the effects of visuospatial working memory capacity surpassed even students' prior knowledge of math, a key predictor of learning. Both inhibitory control and set shifting predicted math learning performance when it was measured within ReflexTM but only set shifting influenced learning when it was measured using traditional paper-and-pencil tests. Mathematics anxiety developed early among second-grade students, and playing adaptive learning games did not help reduce it. Students with high visuospatial working memory capacity also demonstrated low anxiety but high performance, whereas low visuospatial working memory capacity students exhibited high anxiety and low performance in and outside of adaptive learning games. Thus, it is important to consider individual differences in visuospatial working memory capacity and executive functions when designing and implementing game-based adaptive learning technologies in the classroom. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]