John's heart has been conditioned to beat rapidly whenever he smells Windsong perfume on a woman. However, John's heart also races when he smells Chanel 5 and other perfumes. This illustrates:

Glial cells are now known to release neurotransmitters such as ___as part of a modulating effect upon ___ activity

A) glutamate; presynaptic B) glutamate; postsynaptic C) GABA; presynaptic D) GABA; postsynaptic

To eliminate alternative hypotheses in experimental single-subject designs, ____ can be used

a. random assignment b. one-shot case cases c. a time series approach d. a nonequivalent before-after design