A new research by Northwestern University (Illinois, USA) says that one deep breath through the nose can strengthen your brain and make your memories sharper.
For their study, the researchers asked 60 participants to make rapid decisions on emotional expressions in the laboratory while recording their breathing. The participants were showed pictures with face expressions of either fear or surprise and they had to indicate which exactly emotion the face expresses.
The results of the study show that individuals were able to identify a fearful face faster if they encountered the face when breathing in compared to breathing out. Also, inhaling individuals were more likely to remember an object. However, the effect disappeared if a person breathed through the mouth.
More information about this research is here.