Geoffrey Hinton

At least I think they do.

I just made that up.

So if you remember something that happened recently, it's not that there's a file stored somewhere in your brain, like in a filing cabinet or in a computer memory.

What's happened is recent events change your connection strengths, and now you can construct something using those connection strengths.

That's pretty like what happened...

you know, a few hours ago, or a few days ago.

But if I ask you to remember something that happened a few years ago, you'll construct something that seems very plausible to you, and some of the details will be right and some will be wrong, and you may not be any more confident about the details that are right than about the ones that are wrong.

Now, it's often hard to see that because you don't know the grand truth.

But there is a case where you do know the ground truth.

So at Watergate, John Dean testified under oath about meetings in the White House, in the Oval Office.

And he testified about who was there and who said what.

And he got a lot of it wrong.

He didn't know at the time there were tapes.

But he wasn't fibbing.

What he was doing was making up stories that were very plausible to him, given his experiences in those meetings in the Oval Office.

And so he was conveying the sort of truth of the cover-up, but he would attribute statements to the wrong people.

He would say people were in meetings who weren't there.

And there's a very good study of that by someone called Ulrich Neisser.

So it's clear that he just makes up what sounds plausible to him.

That's what a memory is.