What exactly is a memory made out of?

From what I understand (keeping in mind I have no experience whatsoever in neuroscience) it is electrical impulses in the brain. When you read the word cat, your mind goes through every single experience you’ve ever had with cats and picks the most appropriate one to pop into your mind, all in a split second. So it might come up with your memory of your first cat. So I think that it’s the neurons firing in your brain that makes you remember something. Just like learning- when you learn a new skill the neurons keep firing along the same pathway while you’re learning so it becomes easier and easier. Like riding a bike. You learn once and never realllly forget, do you? Your brain’s neuron pathways remember.

@shrubbery That is somewhat what I thought from what I read other sources.

So does that mean the neuron itself is now information? Or a memory?

Not exactly sure what you mean by what it’s “made of”, but memory is information, yes. The way this information manifests itself physically is as a set of specific pathways between certain neurons, on which an electrical current travels when the memory is activated (by either a conscious effort to remember, or as a spontaneous reaction to a situation). Basically that’s pretty much it I think. Mind you I am no expert at all, just a curious guy with Google and free time. As far as I know, scientists are now exploring how different brain areas are used for different types of memories (spatial, linguistical etc). But ultimately, the answer to your question is metaphysical in nature and related to that of what conscience really is, and how so much can arise from simple, weak electrical signals. If you ask me, we are centuries away from that discovery (if it is ever made).

Its neurons firing electrical impulses accross the synapes.

The Mind is consciousness, which is all things working together in perfect unity,
Since the mind as in a man is intertwined with ignorance it is suspended in time which is this age.

Because of this ignorance, coupled with knowledge, the mind will have the perception of both past and future, which is time.

The knowledge we have attributed to the past are referred to as our memory.
The knowledge we have attributed to the future are referred to as imagination.

We must realize that the two are actually one and the same.

Memory is stored as connections between many neurons. It is, as people have said, a path of association networks which combine ideas together to form a memory. Thus when you think of say, a specific holiday, your mind is flooded with activations of stuff associated with that holiday. However the cat example @shrubbery mentioned is slightly inaccurate as we usually form a representation of a cat in our mind which isn’t the same as a memory as these representations are ‘prototypes’ for that object and usually don’t actually hold a physical representation. I don’t want to get into that debate though :D. It does utilise past memories, but the processes behind how the prototype is constructed is quite unknown and is unlike normal memories. Although you can argue that the processes behind storing memories (ie rationalisation, shortening etc etc – see Bartlett) are similar.

My lecturer also said something quite interesting which I thought I would share with you on this matter: that memory is a tool used to help us better understand the future. I will let you think about that for yourself :).