The Facial Feedback Hypothesis is concerned with the relative importance of the face for human emotion. Which of the following are consistent with the hypothesis?
a. If Mary changes her facial expression, it may change her emotional experience, and not just reflect it.
b. If Mary makes a Duchenne smile, with contraction of muscles around the mouth and the eyes, this will lead to brain activation patterns characteristic of negative emotion.
c. If Mary were depressed, and then was to have a Botox injection, she might experience increased joy.
d. All of the options are correct.