We know that when we process some information or solve some problem, we need to pull information from long term memory to working memory. There are few factors known to me that can cause a failure during retrival:

  1. Working memory shortage
  2. poor temporal context
  3. The memory was never transferred to long term memory to begin with

Low working memory is something that can be easily diagnosed with Dual n-back tests.

A study on anterograde amnesic patients have shown that they do not appear to have poor temporal order (5), which indicates that maybe temporal context is not to blame when people forget things. However, it is possible that this does not apply on all cases.

This leaves the third possibility: that short term memories do not always get transferred to long term memories. Is this a possibility? If yes, then why does it happen?


  1. Types of memory
  2. Role of working memory
  3. Temporal context
  4. How is information transferred into long-term memory?
  5. Anterograde amnesia and temporal order
  6. Dual n-back test
  • $\begingroup$ Hi Spero, You've got an incredible bunch of questions here. If you could narrow your question down to only one of them, it will become far easier for someone to answer it. Then, in a follow up post, you can ask for another one and so on. As is, the question is too broad. $\endgroup$ Apr 5, 2017 at 6:23
  • $\begingroup$ Done. Not sure if it turned the question more vague though, because the nature of the question has to leave possibilities open. By shortening it, I am assuming a lot of things that I have no clear idea about.. $\endgroup$
    – Spero
    Apr 5, 2017 at 7:32
  • $\begingroup$ Perfect! You've got a +1 :) Hope that we have someone who can answer your question. And if you have any other questions, feel free to ask them in separate posts of course :) $\endgroup$ Apr 5, 2017 at 7:40
  • $\begingroup$ I find it strange that anterograde amnesia has as poor recollection from working memory as normal people have from long term memory (link 5). I used to think that only retrograde amnesia affects the hippocampus. $\endgroup$
    – Spero
    Apr 5, 2017 at 12:34
  • $\begingroup$ It seems my fear was justified. I have destroyed the question by assuming that crystallized intelligence comes from episodic memory. I think I should study procedural memory, and this question needs to be put oh hold for now. $\endgroup$
    – Spero
    Apr 5, 2017 at 16:54

1 Answer 1


First we need to establish the link between crystallized intelligence and the types of memory. Long term memory can be divided in two parts: Procedural and declarative. Types of long term memory

Episodic memory is recollection of events, semantic memory is recollection of learned facts, and procedural memory includes priming, classical conditioning, skill based learning etc and does not require intentional or conscious recollection of an experience (1).

Among these types, Howard and Kahana's model of temporal context theory is only applicable to the declarative branch (2).

The answer to the question depends on which type of problem solving we are talking about. All three types of memories get used during learning. Problem solving requires skill based learning. But we must also remember a lot of facts in order to solve certain real world problems. Practical experiences also come in handy. However, if we can recall all the related facts but still fail to solve a problem, that indicates poor skill-building. According to Cattell‘s (1971, 1987) Gf-Gc theory, fluid intelligence causes crystallized intelligence (5). therefore, low fluid intelligence might be a reason behind poor skill based learning.

"failure to transfer skill from Hippocampus to cortex" is not likely to happen because skills do not seem to have any short-term and long-term phases. Excerpts from a recent study (6):

We have shown that when people adapt to successive and opposing sensorimotor transformations, they fail to consolidate learning of the first even when the two transformations or tasks are separated by 24 hr.

From a meta-analysis (4):

This implies that a procedural memory may never become fully stable and instead remains vulnerable to interference. When exposed to task B, participants may have retrieved the procedural memory associated with task A and modified it, ‘overwriting’ the memory for task A with information relevant to task B............ It implies that learning a new skill leads to the automatic destruction of another skill. It would never be possible to have skill in more than one task! Our ability to acquire multiple skills may depend upon having contextual cues available to signal the switch from one task to another.

This theory proposes that our procedural memory has a completely different type of contextual cue system, one that cannot differentiate between multiple skills as efficiently as episodic memory can. This theory also explains why ADHD is such a barrier in learning.

Now we can guess what type of memory is involved in skill learning: When a new skill is being formed by Gf, it is likely utilizing the info available in short term memory to do so. When a skill is being recalled, It goes to working memory for utilization.

In conclusion: Forgetfulness indicates inefficiency in declarative memory, while poor skills might indicate low Gf and/or poor attention span.

Questions remaining:

  1. What causes inefficiency in declarative memory?
  2. How to strengthen our procedural memory? Can practice help?
  3. Why do people who find it easier to learn through practical and struggle to grasp abstract concepts?

But these questions deserve new topics.


  1. Green REA, Kopelman MD. Neural organization of memory andmemory impairments. In: Trimble MR and Cummings JL, eds. Contemporary behavioural neurology. Boston: ButterworthHeinenman, 1997; 139–152.

  2. https://pdfs.semanticscholar.org/5b83/58754a92cf648f3c5ccea7f34df62bba1e74.pdf

  3. https://www.cambridge.org/core/journals/journal-of-the-international-neuropsychological-society/article/interdependence-of-episodic-and-semantic-memory-evidence-from-neuropsychology/1A97EFA24F2CDED16D12964AD5EE67F9

  4. http://www.cell.com/current-biology/pdf/S0960-9822(04)00937-6.pdf

  5. http://ir.uiowa.edu/cgi/viewcontent.cgi?article=2639&context=etd

  6. http://www.cns.atr.jp/~kawato/Ppdf/CaithJNS04.pdf

  • $\begingroup$ If this isn't a good answer then I'm producing rubbish haha. Excellent answer. +1 from me $\endgroup$ Apr 6, 2017 at 19:45
  • $\begingroup$ @RobinKramer I guess this answer of mine is invalid. If motor skills trigger LTP directly in motor cortex, that means this type of memory still has short term phase, but do not use hippocampus. $\endgroup$
    – Spero
    Apr 21, 2017 at 10:12
  • $\begingroup$ Visual cortex also exhibits LTP. I wonder if all types of memory go through LTP in the cortex first, even the declarative ones that come from hippocampus. $\endgroup$
    – Spero
    Apr 21, 2017 at 10:37

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