I want to know the answer to the following question:
What causes humans to underestimate time intervals?
All the background I'm provided with is that "Such chemicals will either excite or inhibit the firing of neurons in the brain, with a greater firing rate allowing the brain to register the occurrence of more events within a given interval (speed up time) and a decreased firing rate reducing the brain's capacity to distinguish events occurring within a given interval (slow down time).". Is that enough to answer the question?
Answer: no