How does the human brain decide which memories to store the brain uses a number of automatic mechanisms
to determine what information to retain.
Everything else naturally fades away.
The brain's overriding principle given to it from millions of years of evolution is to retain whatever
is likely to be useful for long term survival says the future utility of information is impossible to
predict.
The brain uses a number of heuristics that have been honed for the millenia.
Here are some of the most well studied first repetition things that happen repeatedly are never highly
significant or irrelevant.
However even if they are irrelevant like the background noise to tune out they must be identified so
that they can be removed from perception.
When studying for a test students often use repetition to activate the brain's importance circuits.
Next primary and recency.
Things that happened first are often more important because they predict what comes later and things
that happen most recently are often the most relevant because they are closest to the present things.
In the middle tend to get forgotten.
This is why so many presentations start and end with an overview of the key points.
Next surprise.
Anything that is unusual stands out.
This can include an uncanny coincidence or an event that led to something unpredicted an entertaining
science teacher will ask students to guess what will happen and then show that the opposite happens.
Setting up the experience of surprise increases retention.
If you are thinking of calling someone and the phone rings and it's them you'll remember that for a
long time because the coincidence is so unusual since you forget all the times you thought of calling.
We've got the phone ringing.
You are left with the false impression that the coincidents were special.
Next emotional impact emotions are one of the ways the brain prioritize perception and action.
Emotions are a way of assessing situations according to their role in our instinctual survival program.
A moment correlated with a strong emotional state will be retained for a long time which is why for
example leading up to a car accident people have the memory of time slowing down and noticing every
detail.
Time didn't actually slow down.
It's just that a lot of detail got recorded and so the event is remembered in this way.
Next leads to positive or negative outcome.
The systems in the brain that learned behaviors and habits are especially tuned to the eventual outcome
or an action or perception.
This is why activities such as gambling can be so tenacious with a slot machine.
Most of the time nothing happens but sometimes the bell rings and the sign flashes when are each dose
of the Word assures that more waters go into the machine.
Addictive drugs like nicotine and cocaine activate your word circuits directly causing everything that
led up to taking the drug to be given automatically priority by the brain.
Dopamine is a neurotransmitter central signaling reward and activating procedural memory formation.
When something leads to a strongly unpleasant outcome.
Emotional circuits labelled the preceding events as fearful.
All right we've studied the ways of which the human brain decide which memories to store those are repetition.
Primary and recency surprise emotional impact and leads to positive or negative outcome.
In the next lesson we are going to have a look at how to forget a bad memory.
See you there.