Long-Term Memory: Semantic & Episodic Memory

When trying to analyze the story recall, I decided to develop a coding scheme that helps me to investigate the data. Following is the counts of accuracy of the three-time recalls from the recall grid. Numbers in black are the 1st recall, red is the 2nd, and the blue is the 3rd. My coding scheme is based on the following rules:
1) Original sentences are chopped into units according to the meaning. Each unit contains one major concept/element.
2) If the key meaning matches the original sentences, it is counted. (content accuracy)
3) If the recalled meaning is distorted from the original meaning, it was not counted.

*Please notice that the coding scheme is subjective and not very rigorous. There may be some errors in the following data.*

Based on the following data, one of my observations is that we tend to remember the general meaning of a passage and the superficial aspects are easily forgotten. Take the following story recall for example. The main concepts that construct the story and keep it flowing are the frequently recalled elements (e.g. two young men went down the river -> men in the canoe asked if they want to join the war -> one man thought he may be killed and his relatives do not know where he have gone-> one man went and the other returned home, etc.) On the contrary, the superficial elements which do not influence too much on the key meaning of story are hard to be recalled. (e.g. one night; it became foggy and calm; they heard the noise of paddles; he became quiet; His face became contorted, etc.)

Beside the accurate recalls, it is interesting to look at the unsuccessful recalls. In some story recalls, we can see that several key concepts and the frame of the story were remembered, and then we try to reconstruct it from the presented information and our existing knowledge (schema). Ineffective encoding (just like myself, I did not pay enought attention while reading the story at the first time), unsuccessful retrieval and the influence from our schema lead to omissions and distortions. (e.g. two young men-->two Indians; “Quick, let us go home: that Indian has been hit” --> they receive word the person they needed to kill had already been shot. So, they went to his house and started a fire, etc.)

One night -- 1 2 0
two young men – 11 11 11
from Egulac -- 3 2 3
went down to the river –10 8 8
to hunt seals --6 4 4
and while they were there it became foggy and calm. -- 2 1 1
Then they heard war-cries, --8 5 6
and they thought: "Maybe this is a war-party". – 4 3 3
They escaped to the shore, and hid behind a log. -- 2 1 1
Now canoes came up,-- 6 3 4
and they heard the noise of paddles, -- 1 1 1
and saw one canoe coming up to them.-- 4 5 4
There were five men in the canoe, --6 3 2
and they said: "What do you think? We wish to take you along. We are going up the river to make war on the people." –9 9 9
One of the young men said, "I have no arrows."-- 5 2 3
"Arrows are in the canoe," they said.-- 5 4 4
"I will not go along. I might be killed. My relatives do not know where I have gone. –10 9 9
But you," he said, turning to the other, "may go with them." --4 4 4
So one of the young men went, but the other returned home. --7 7 6
And the warriors went on up the river to a town on the other side of Kalama.-- 1 1 0
The people came down to the water and they began to fight, and many were killed. –6 4 4
But presently the young man heard one of the warriors say, "Quick, let us go home: that Indian has been hit." --5 5 4
Now he thought: "Oh, they are ghosts." --1 1 0
He did not feel sick, –5 4 4
but they said he had been shot.
So the canoes went back to Egulac --2 2 1
and the young man went ashore to his house --6 2 5
and made a fire. ---2 2 1
And he told everybody and –5 5 5
said: "Behold I accompanied the ghosts, and we went to fight. -- 2 1 1
Many of our fellows were killed, and many of those who attacked us were killed. -- 2 1 1
They said I was hit, and I did not feel sick." –5 1 0
He told it all, and then he became quiet. – 0 0 0
When the sun rose he fell down. –4 4 3
Something black came out of his mouth. --5 3 3
His face became contorted. –1 0 0
The people jumped up and cried. --2 1 1
He was dead. –9 9 9

Concept Map

(The article, EXAMINING CONCEPT MAPS AS AN ASSESSMENT TOOL, is helpful for me to do the analysis. Some of the following terms are from this article. )

Since this is not an easy task for the “victim”, I asked my guinea pig (an Asian male) to choose a topic that he is really interested in. Therefore, I found a website about “Basics of DNA Fingerprinting” http://protist.biology.washington.edu/fingerprint/dnaintro.html according to his interest. Before going into the lesson, I also showed him some concept map examples, so he had an idea of what he is going to do after learning the material.

I decided to ask him to draw a low-directed concept map, which is the concept map that “students are free to decide which and how many concepts they include in their maps, which concepts are related, and which words to use to explain a relationship” (Ruiz-Primo, 2004, p.2) I thought it would provide more room for the subject to reflect his understanding. In addition, I also believe that different people can produce different concept map and I want to see what kind of concept map he will construct. click here to see the big picture of the directedness of the mapping tasks.

Here is the concept map constructed by "Inspiration" after the participant learned the “Basics of DNA Fingerprinting” for about 30 minutes. click here to see the big picture

Although I don’t feel I can use a lot of what I read from Mancuso and Shaw’s article to analyze this concept map task, I do agree one of their perspectives –“meaning is not extracted from nature, but projected by man upon it” (p.21). People construct meaning and understanding by their cognitive system. Take the subject for example. He has engineering background. Although he does not have much biology background, he showed interest to learn the material and may be able to pull out available schema to help him to absorb and organize the information.

However, “concept map” is a new concept for the subject. He felt frustrated to use it to express his understanding. He did not think it is able to fully express what he has learned. Looking at his concept map, he was able to structure an outline/framework of the material, but some information was omitted. I think this could be one of the disadvantages of the low-directed concept map.

Long-Term Memory

This time, my guinea pigs are one Asian male and one Asian female. Both of them asked to see the list after the immediate recall to check what they have missed. I think this would affect their performance of the delayed recall.

First, we could obviously see the decay of the long-term memory. However, the delayed recall was not very different from the immediate recall. I was surprised that their performance was better than Ebbinghaus’ forgetting curve (1 hour later, the saving rate would drop to 42% or 43 %).

It is interesting to see that in the immediate recall, the male started from the end of the list and the female could mostly follow the original sequence for the first five words, and then kept on the words that could be chunked together (such as wood & green, bottle & jogging).

For the male, he said he tried to use memorize them alphabetically, but mostly he did not use specific strategy(maintenance rehearsal). For the female, she also tried to memorize the first letter and also picture imagines(visual imagery), and make connection between words (more elaborative rehearsal). Therefore, the mnemonic did help her memorize better.

Second, the male participant recalled from the end of the list when recalling immediately (recency effect). Interestingly, he started from the beginning of the list when recalling again after one hour. However, the female participant still recalled from the beginning of the list. One of the confounding variables is that they were able to revisit the list from the immediate recall. This explained why they can remember words after one hour that they did not in the immediate recall.

It would be interesting to study the difference between male's and female's memory.

Memory Test

My guinea pig is a native Chinese speaker. When I asked him to recall numbers in English,he expressed his difficulty to translate the numbers from English to Chinese. The result shows that there were some missing digits or switching digits in his recalls. In these five sets of numbers, the first two digits were all correct, and also the last two digits of the first three sets. However, he could not recall a couple of last digits in the 12 digit recall. The primacy effect was apparent here, but the recency effect did not show in the long serial recall. The possible explanation is that in the serial recall, he didn’t only need to remember the numbers but also their positions in the list. This took space in his working memory.

Besides reading the numbers in English, I also tested him in Chinese. This time, he almost recalled all the numbers correctly except few minor errors. Surprisingly, he even got the 12-digit numbers correct. In addition to the proficiency and familiarity with the native language, one of my observations is that Chinese only has single syllable for each number (from 0 to 10); on the other hand, several English numbers have more than one syllable. Therefore, he could store more Chinese numbers in his working memory.

While recalling letters, he had no problem with remembering 6 and 8 letters correctly. The primacy effect also worked here, but the recency effect did not show in the 13-letter recall. The most difficult one is the one has fewer vowels. It may be due to the difficulty of making up words and chunking them with only consonants.

When recalling words, he had no problem with remembering the first two and the last one or two words (primacy and recency). The words in the middle can be easily switched or missed, especially the ones before the last two words. The last sentence was the easiest for him to recall except two or three minor errors. We can see that when items make meaning in our mind, it is easier to recall.

Generally speaking, the numbers of unit that he can remember approximately followed the 7± 2 rule. One of the exceptions was when he lost his attention and only recalled one or two unites. Another is the last sentence that has meaning and easy for him to recall most of it.