Emotion robustly affects the quality of cognitive-motor performance under conditions of mental stress. As such, the regulation of emotion is critical to successful execution of motor skills during emotional challenge. Previous investigations of the stress-performance relationship have typically focused on behavioral outcomes, however, few have adopted a cognitive neuroscience approach to examine the involved mechanisms underlying this relationship. Furthermore, it is unclear if individuals who have a history of superior performance under stress (stress resilient population) exhibit brain responses characterized by an efficiency of neural processing and an adaptive emotion regulatory strategy. Using functional magnetic resonance imaging (fMRI), the present study examined activation in critical brain regions during affective challenge (i.e., presentation of International Affective Picture System negative images and Sport-Specific negative images) in 13 elite athletes (intercollegiate football players who have demonstrated successful execution of cognitive-motor skills under mental stress) relative to an age-matched control group (n=12). The present dissertation is organized into three main sections. The first report, entitled Brain Processes during Motor Performance under Psychological Stress, an Independent Component Analysis of EEG, is an examination of brain processes during competitive stress. This study revealed non-essential neuromotor cerebral cortical noise with a quantified increase in complexity during a cognitive-motor task. The second report is entitled Efficiency of Affective Brain Processes in Expert Cognitive-Motor Performers during Emotional Challenge. This fMRI examination of elite athletes revealed processing economy in brain regions critical to self regulation, management of emotional impulses and social cognition. The third report, entitled The Specificity of Neural Regulatory Processes during Emotional Challenge in a Stress Resilient Population, examined with fMRI if elite athletes spontaneously engage in cognitive reappraisal during the presentation of arousing sport-specific images. Results suggest that elite athletes process sports-relevant affective information in an automatic manner, congruent with a cognitive reappraisal strategy, which neutralized the negative impact of the scenes. In conclusion, the results suggest that elite performers are important models of stress resilience and respond not only in an efficient manner to stressful events, but demonstrate an adaptive regulatory response when challenged within their domain of experience.