some kind of associative memories
no.memories are stored in your temporal lobes.
Typically, memories are stored in Dumbledore's pensieve (when not in their original owner's heads). But specifically in Deathly Hallows, Snape's memories are stored (temporarily) in a vial that Hermione conjured. They are later dumped into the aforementioned pensieve.
In the cerebellum!
memories are stored as a series of gear rotations and switches
Memories are stored in the brain through the strengthening of connections between neurons, forming neural pathways. Skills are stored similarly, with repeated practice and reinforcement leading to the creation of specific neural networks dedicated to that skill. Both memories and skills are encoded in different regions of the brain, depending on the type of memory or skill being stored.
Association
Not really, they are just memories and chakra stored in his seal.
Yes once the brain has started to develope first memories can start to be stored. Although you may not be able to recall whole days you will still have fragments of events as first memories.
The brain structure related to processing memory is the hippocampus. However, once processed, memories are stored through the cerebrum.
B.======================================================Allow me to add:each species and culture shares ancient memories, stored in the unconcious part of the mind.
stored in the Hippocampus.