Buchanan, Tranel, and Kirchbaum (2009) Studied Three Groups of Participants

Multiple Choice

Buchanan, Tranel, and Kirchbaum (2009) studied three groups of participants, one of which had damage to the hippocampus, one that had similar brain damage but not to the hippocampus, and a control group of participants. The researchers assessed responses to the three groups both before and after they were exposed to stress. The hippocampus group showed a decrease in cortisol response to stress, whereas the other two groups shoed increases. Which of the following statistical tests was used to test the hypothesis?

A) A main effect..
B) A multiple regression.
C) An interaction. d . A correlation.