Memory

How does the memory changes in function of time ?

Click on the brain

By Noah Burge

Maths

Origin

Better ways to remember

Hi. I'm Ebbinghaus.Before me, people studied memory with texts. But every text is unique so the studies couldn't be easily reproduced. So I decided to make people remember combinaisons of 3 letters like JOR or SIL. So... What do you want to know ?

Who are you ?

What did you found ?

HOw did you test this ?

Stability of the memory (in s^-1)

Retension of memory (0≤R≤1)

R = e^(- t/S)

Time (in s)

derivative

Limitations

Limitations

This model is easy to understand but it doesn't account for repeted study sessions wich where later proven to greatly diminush the rate at wich we forget informations. It also doesn't account for traumatic memories that can be remembered much longer than regular memories. Finally, this model is based in memorisation of syllables. We don't know whether this model might work in other cases.

the

Derivative

We have R =e^(-t/S) with S a constant, t a variable within the reeals and e the exponential. We are in a case where f(x) = e^u(x) with u(x) here beeing -t/S. So, we'll have f'(x) = u'(x) * e^u(x) But what is u'(x) ? Well, it is, here the primitive of -t/S = t * (-S)^(-1). We can now use the formula f(x) = k*x, so we have f'(x) = k. Here k = (-S)^(-1) So, we have our derivative : R' = -1/S * e^(-t/S) . S is positive so (-1)/S is negative and, as an exponential has to be positive, R' will be negative. The function decreases over time : We forget things (shocking !)

Better ways to remember

Ebbinghaus tried using mnemothecnics (associating images to words or concepts). He compared how well he perform with and without mnemotechnics. They seemed to prolong the time we need to forget a word. Futher studies from Ebbinghaus showed that spaced repetition (learning an information multiple times), decreases the rate at wich you forget informations. Ebbinghauss described that state as a state of "over-learning". Using flash-cards can be usefull as it forces oneself to recall data (therby testing it) and re-learn forgotten data points. Today, we even have apps on our phones that exploit a form of the forgetting curve (described in the "Maths" section) to make you recall information at the optimal moment so that you never forget it.