The group of subjects selected for observation in an empirical study is known as the ____________________

Around _____ percent of all adults may experience an episode of severe unipolar depression at some point in their lives.

A) 6 B) 18 C) 28 D) 42

The reappearance of a learned response after extinction has occurred is called ______

a) counterconditioning b) instinctive drift c) spontaneous recovery d) stimulus discrimination