Stefan has volunteered to participate in an experiment studying vision in which he will wear a pair of glasses that invert his vision. because of after about a week, he is able to perform his usual activities, like riding a bike or reading a book.

   Perceptual adaptation

Explanation:  Since Stefan was involved in an experiment concerning the study of vision and the wearing of glasses that invert his vision, it took some time to perform a perceptual adaptation. Perceptual adaptation is, in fact, the means by which the brain perceives differences, most often as in this case in the field of vision, which Stefan witnessed.

answer; i believe the correct answer is (federalist);

rain should be the answer.