Before his study begins, dr. holly lets the subjects know that their participation will include a small, weekly time commitment and may arouse negative thoughts and feelings about past academic experiences. this is an example of:

I believe the answer is: Informed consent

In research, informed consent refers to the full knowledge of the possible risk and benefit that might be caused by the research.
The experiments do not necessarily need to reveal the specific mechanic of the research in the beginning because it might influence subject's behavior, but they have to reveal them by the end of the research.