Question: When someone gets knocked unconsciousness when they wake up why do they remember barely anything?

Jess Smith answered on 17 Mar 2014:

This isn’t my area of science, but we can have a go!

When somebody gets knocked out sometimes they can’t remember what happened immediately before or after (this doesn’t always happen though). People are knocked out through impact to the head. Imagine that you ran in to a lamp-post, well as your head hits the lamppost your body stops, but your squishy brain keeps moving inside your head and hits into your skull. The impact causes your brain to ‘shut down’ temporarily to avoid damage to systems (knocking you out). There is a lot we don’t know about what happens to the brain as you get knocked out. Memory is stored in your brain in two ways- short term memory and long term memory. The short term memory is not very secure, and so may be lost when you have an impact to the head(making you forget what happened immediately before). Other areas of your brain can be effected by a big knock to the head too, for example your speech or your vision. This is because all of the processes in your brain are because of something physically happening inside your brain. If that area is damaged because of an impact, then the physical process may not be able to work properly. So if the bit of your brain that deals with language is damaged, then maybe you wont be able to speak properly.