In an attempt to determine whether noise interferes with performance, Marc randomly assigns participants to take a math test either while listening to loud music or in silence. In this study, the presence of absence of noise would be considered the:

Leo recently retired from working as a mail carrier for forty years, and then unfortunately his wife passed away. What will be most helpful in protecting Leo from experiencing a marked decrease in intelligence over the next few years?

A. going for long walks outdoors B. doing word and number puzzles C. reading news articles online D. joining a senior activity group

Which of the following terms best reflects Fischer's perspective on a person's cognitive performance in a specific domain?

A. irrelevant B. inconsistent C. quantitative D. universal