<span>A depressant must reduce mental activity and decrease physical activity. A depressant acts by interfering with and reducing the levels of activity in neuro-transmitters. This serves to slow down the chemical processes within the brain which consequently lowers the level of mental activity or arousal. The brain also programs the body to reduce the levels of physical activity in a proportionate manner.</span>
Answer:
Tuskegee.
Explanation:
As the exercise describes, one of the most shameful violations of research ethics to date, nearly 400 African American men from Tuskegee (later called the Tuskegee syphilis experiment) were not informed that they had been diagnosed with syphilis and were not provided with available, effective treatments for this illness. The aim of this study was to observe and analyze how syphilis proceded when untreated. So, this men were told they were being treated for free.