Original sentence: Some people consider this to be a remarkable aspect of human physiology; others consider it to be an illusion arising from the way medical experiments are conducted.The placebo effect is the phenomenon that the belief that a pill or procedure is therapeutic can itself in instances apparently alleviate a person's symptoms
Edited sentence: A remarkable aspect of human physiology is that just the belief that a pill or procedure is therapeutic can itself in instances alleviate a person's symptoms.This is called the placebo effect