The Montreal Imaging Stress Task The study will use a block design of three, six-minute runs separated by two-minutes of rest for feedback, for a total of 24-minutes. During each run, participants will be exposed to 40-second blocks of three different conditions (rest, control, and stress). Prior to the task, a research assistant will meet with each participant and described the parameters of the task. The participants will be shown images of what the screen will look like during each condition. The participants will be instructed to relax during the rest condition and focus on the screen. During the control condition, the participants will be asked to answer math problems as accurately as possible but will also be told that their responses will not be recorded. During the stress condition, the participants will be asked to perform the math task as quickly and accurately as possible. They will be given immediate feedback about their performance and will be able to see the performance level of an "average" person through a performance bar that will be located at the top of the screen. A strict time limit will be enforced throughout the stress condition. The participants will be told that the average person would answer about 85% of the questions correctly, while in reality, the program's algorithm limits the participants' performance rate to between 35-45%. At the end of runs one and two, the participants will be given negative feedback from the investigator and will be urged to improve their performance so that their data may be included in the study. To minimize the effects of scanner drift, the beginning condition will be counterbalanced between participants. However, the sequence of conditions will be constant (i.e. control condition will follow the rest condition and the stress condition will follow the control condition).