Does procedural memory include learning complex thoughts?

[icakeov]

Hello,
I've heard about "H.M." and similar patients that lost the ability to create declarative memories, but can still create non-declarative memories.

I was wondering, since one in this condition can for example, develop a habit of drawing complex shapes, and not know they did it, can they similarly, if they keep repeating it, learn to say and pronounce complicated concepts? For example, to learn to recite some equation or a long poem, and if they have some new concepts or words that the patient doesn't know, the patient would have no idea what he is saying, but would still do it?

Another example that comes to mind is if they were to be instructed to greet someone in a new language and eventually learn to say that expression, but have no idea why they are saying it, nor what it means? So every time this foreigner would walk into the room, would they automatically greet the person in a different language?

In essence my question is whether, as much as declarative memory makes connections to different facts in the brain, it still uses non-declarative processes to actually learn how to actually say the factual statement?

Hope this made sense, any thoughts appreciated.

 

[Fervent Freyja]

Just because a person may have to rely on non-declarative memory doesn't mean that they aren't entirely unaware and cannot understand what they are doing at that moment, they may just not remember the experience. You can liken it to driving a car, where most of the drive you aren't retrieving declarative memories, but do have more muted awareness of what is happening.

Watch http://%20https//www.eurekalert.org/pub_releases/2016-06/jhu-haw062216.php video inside the article, note how the woman can explain the procedure of drawing clouds with watercolors, but cannot recall having done one herself, nor can she give a technical explanation. She most likely cannot initiate projects on her own, and would need a person to cue her when beginning a painting, although she could still complete the painting on her own. She would be aware of what was happening and may experience the same feelings as a normal person during the painting.

In essence my question is whether, as much as declarative memory makes connections to different facts in the brain, it still uses non-declarative processes to actually learn how to actually say the factual statement?

Not usually. Learning through declarative processes is much more common and efficient. My daughter was using declarative memory earlier when we were studying flash cards (objects in astronomy). Very little of that learning would have been done through non-declarative processes (maybe if I quiz her repeatedly).

 

[icakeov]

Thanks for your response Freyja!
That is interesting, so, a big portion of her declarative memory was wiped but not all of it.

Is the hippocampus mainly involved in the process of creating declarative memories, but when they are made, they run independently of the hippocampus? I've seen this video where I understood that the Entorhinal Cortex actually stores the declarative data. So perhaps a portion of her Entorhinal Cortex was damaged, which wiped out her memory of her marriage, but some other part was intact, the one that had memories of painting? I am mainly speculating in this one.

And yes, I was actually going for your very last statement in brackets. If someone's hippocampus were destroyed, and they were to repeat an action (with someone's guidance) of being coached on repeating words that involve strictly declarative memory, even if they were to understand what they are learning in the moment, and enjoy it and all, after many repetitions, would the person actually know names of new astronomic objects, but not know how they know it, nor what it all even means?

I know that this happens with a non-declarative motor actions, but is the "procedural pronunciation" of astronomic objects after a while actually partially non-declarative motor function? I imagine it would have to be. And the actual meaning of it would be in the domain of declarative memory, that is, if one has those essential limbic structures like hippocampus and the Entorhinal Cortex?

Thanks again! :)

 

[atyy]

Very old declarative memories seem to be independent of the hippocampus.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2277361/
http://www.pnas.org/content/105/7/2676.full

 

[icakeov]

Great articles! Thanks atyy!

 

[icakeov]

I came to the forum with the question below, and it suggested this thready. So I thought I might as well chime in here with my question as it seems to be quite relevant.

I just watched some video that talked about the HM patient: when he was asked "what did you do yesterday", one of his answers was: “I don’t really remember things”.

Is he saying this because he had said it so many times, that it became procedural memory? Because, how would he otherwise know that he doesn’t really remember things?

My random guess: he would have said "I don't really remember" anyways, but then if he'd said that enough times, the word "things" could have latched on (amongst perhaps other alternatives like "never", etc.) through procedural (non-declerative) memory? For example, if the people they knew him kept telling him that he didn't remember things, and after him repeating that enough times to himself, it stuck. Or is the process quite different?

And another addendum to this question, if these patients were never told that they "have a problem", would they just live "happily ever after", or would they still intuitively know that something's up? Basically, do they need to be told, until they "procedurally learn"?

 

[atyy]

I'm not sure. H.M. was also able to learn the spatial layout of rooms in his new home that he moved to after his amnesia. I don't think we know whether this was procedural (or independent of the medial temporal lobe), or whether it was because he had still had some parts of the medial temporal lobe intact.

 

[icakeov]

Thanks @atyy! I was just learning about "place neurons". I am guessing they help out with spatial layouts which create episodic memory? If that's the case, is it just not yet known whether these neurons function exclusively within the hippocampus? Because if H.M. hadn't had any hippocampus left, that would actually suggest that procedural memory systems could create episodic memory too?

 

[icakeov]

Another question that came to mind on this topic about H.M.:

He was able to learn a complex procedural process like drawing stars in a mirror because someone instructed him to do so. But even though he learned that procedural memory, would he been even aware that he could do that task, and more so, would he be able to teach it?

Would it even cross his mind to show this to someone? Or would he need at least a cue, say, if someone left a mirror, pen and paper around, and H.M. would by sheer habit pick it up and start doing it. But would he ever instruct someone about it and be able to explain how it works?

My guess is that he wouldn't. Short of just doing the task, since he lacks declarative memory, he would never spontaneously start explaining what he is doing and how it all works. (unless someone asked him what are you doing..? )