Write a journal before the exam

I don't remember when was the first time I started to have a great interest in studying human brain. 

But for sure, physio-psyc had an influence on me. 

It's interesting to notice that when we're under pressure, we tend to perform less better than under normal circumstance. Taking exam for example. 

"I did read that chapter last night. But why can't I remember it?".

The brain Scientists try to help us find what is going in our brain during that time. So when we solve a problem (answering the exam question, having an interview, etc) there are some parts actively involved here. Frontal lobe (responsible for thinking process and proble solving) and amygdala (the limbic system which is responsible to regulate our emotion). 

So when we're underpressure, the limbic system can disturb the work of frontal lobe. We feel nervous and then forget about the topic we study before. 

The scientists then make an experiment. Two groups of high school student are about to take a biology exam. One group is given a journal for them to write down their feeling before taking the exam. Another group isn't. 

At the end of the study, the researchers find that students who write journal perform better than those who don't. Writing down our feeling before taking exam appearantly can reduce the anxiety. Blocking the limbic system interrupting the frontal lobe. Making the mind clear. 

It seems that sherlock holmes is way a head with his saying, "put away your emotion when working on the problem for it may unclear your mind".