Context: Psychoactive drugs can impair the judgment of time. Stimulants can lead both humans and rats to overestimate time intervals, while depressants can have the opposite effect. The level of activity in the brain of neurotransmitters such as dopamine and norepinephrine may be the reason for this. 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).

Question: What type of drugs can impair the judgement of time?
Answer: Psychoactive drugs

Question: Stimulants lead humans to overestimate what?
Answer: time intervals

Question: What causes humans to underestimate time intervals?
Answer: depressants

Question: The level of what is the reason stimulants and depressants change human perceptions of time?
Answer: The level of activity in the brain of neurotransmitters

Question: Such chemicals do what to the firing of the brain's neurons?
Answer: either excite or inhibit the firing of neurons

Question: What do rats not understand?
Answer: Unanswerable

Question: What does a decreased firing rate allow more of in the brain?
Answer: Unanswerable

Question: What does the presence of neurons impair the judgement of in rats?
Answer: Unanswerable

Question: What can neurons lead humans and rats to overestimate?
Answer: Unanswerable

Question: What causes rats to underestimate dopamine levels?
Answer: Unanswerable

Question: What type of drugs can impair the judgement of events?
Answer: Unanswerable

Question: Stimulants lead humans to underestimate what?
Answer: Unanswerable

Question: What causes humans to estimate time intervals?
Answer: Unanswerable

Question: The level of what is the reason stimulants and depressants change human perceptions of neurons?
Answer: Unanswerable

Question: Such events do what to the firing of the brain's neurons?
Answer: Unanswerable