What is the difference between "distractors" and "foils" in experimental design in psychology?
As far as I know foils and distractors are the same.
For example, in constructing multiple choice questions, with only a single correct answer, the incorrect answers are distractors or foils (or misleads), and the correct answers are targets.
This terminology may vary depending on sub-disciplines. I would suggest you ask your supervisor for some clarity.