Reference no: EM133455614

Identify the flaws in each of the experiments below and describe how the experimental design should be corrected:

1. Pedro is working his honors thesis and wants to get a series of experiments done before the end of the fall semesters. He ordered his animals and his chemicals at the same time, but unfortunately, the drug he needed for his experiments was backordered for a month. He used this time to gather all of his control data, then when the drug arrived, he collected the data on his drug-treated group.

2. Sylvia is interested in studying the effects of caffeine on memory. She has two groups: one that drinks 4 cups of decaffeinated coffee daily for 10 days and one that drinks 4 cups of caffeinated coffee daily for 10 days (the subjects do not know what treatment group they have been put into). On day 10, she gives each group a list of 20 five-letter words to study before they consume their decaffeinated or caffeinated beverages. She tests their word recall 1 hour after they have consumed their beverages.

3. In a study of cocaine addiction, one rat showed exceptionally high levels of motivation for cocaine as determined by lever-pressing behavior. This animal also showed high levels of dopamine release in the nucleus accumbens (a brain region associated with reward). The researcher concluded that dopamine acting within the nucleus accumbens causes high motivation for cocaine consumption.