A neuroscientist believes that proteins form plaques in the brain that cause Alzheimer’s disease. He gets a sample of older adults, measures the nanograms/liter of protein in spinal fluid, and measures short-term memory as the percentage of words in a list that are recalled.

a. Generate a sentence that states the question the researcher is trying to answer.
b. List the variables and label them as independent and dependent.
c. Determine what type of study is being done: correlational, experimental, or quasi-experimental.
d. If the study is correlational or quasi-experimental, come up with a plausible confounding variable and explain how it affects both variables.