Dr. Laidback thinks benzodiazepine medications may help improve memory for those with high anxiety. So, Dr. Laidback is studying the effects of anxiolytic drugs on high anxiety patients' memory and brain activity. He plans to give half of the participants Xanax (a benzodiazepine) and the other half a placebo. Then he is going to give each participant an fMRI scan and a memory test. The memory test is a list words that the participants are asked to memorize and then repeat back.What is the operational definition of the DV? (in other words, how is the DV you named above being measured)?