“This File Is Read-Only”

Surprisingly, which copy is used might also be linked to how easy it is to change a memory– or to use it to create a new one.

The memories stored for a short time after acquisition by the late-born neurons can be modified and rewritten. This means that remembering a situation shortly after it has happened primes the late-born neurons to become active and integrate present information within the original memory.

On the contrary, remembering the same event after a long time primes the early-born neurons to be re-activated to retrieve their copy, but the associated memory can no longer be modified.