Thursday, January 19, 2012

Memory and VARK Part 4: Working Memory

For my final post on Baddeley’s book, Your Memory, A User’s Guide, I will be looking at his discussion of working memory and whether this can provide relevant information for VARK theory. In the past three posts, I have reviewed Baddeley’s discussion of sensory memory, his discussion of the process for the encoding of memories and his discussion of semantic memory. In general, I am still having some problems figuring out what exactly VARK theorists are citing Baddeley’s book for. In an effort to figure out the answer to this, I turn my attention to the final portion of his book where differing modalities are discussed- working memory.

Baddeley is known and discussed in upper division (usually) psychology classes for his model of working memory. Most people have heard of the idea that we have short-term memory and long-term memory.  Our short-term memory would be for items that are needed over the next few seconds (or maybe minutes) and our long-term memory would be for things that we were going to store indefinitely (or at least for a long time). Baddeley (along with Graham Hitch in 1974) believed that the function of short-term memory was more than just short-term storage. He believed that its function is to serve as a processor for what we currently are remembering- a so-called “working memory.” Imagine that you study for a psychology exam for an entire month. As you learn new information, you would hopefully put it into long-term memory so that it will help you on exam day. Hopefully, most of the material that you learn will not be constantly on your mind each and every day. You might study here and there, and when you study it is on your mind, but when you are at work or at school (in your other classes), your focus is not on the material for your psychology exam. Now, when the exam comes, you need to access those stored memories so that you can use them to answer the exam questions. When you access that material, it comes into your consciousness and into “working memory.” Baddeley defined working memory as “a system that allowed several pieces of information to be held in mind at the same time and interrelated.”

To illustrate it in a slightly different way, we can think of “working memory” as in use throughout the day as we process the information that comes into our system. As we have a conversation and listen to the words that are coming out of our converser’s mouth, we must keep the words and ideas portrayed earlier in the sentences and conversation to be able to understand the words and ideas that are currently being spoken. As you are reading this sentence in this blog post, you must have the ideas from the earlier sentences from this post readily available to help you understand what you are currently reading. This is a working memory function.

In Baddeley’s model of working memory, he proposes an “articulatory loop system” and a “visuo-spatial scratch pad” (Baddeley and Hitch, 1974).  A cursory glance at the names of these systems may lead one to a “visual” processor and an “auditory” processor. This may be what VARK theorists found useful with Baddeley’s work. So, what are these two systems?

Well, the articulatory loop system is the part of short-term memory that Baddeley believes helps with rehearsing something. When given a list of numbers to put into short-term memory (or even long-term memory), many people simply repeat the numbers over and over. This keeps these numbers ready for access from working memory. Baddeley’s model proposed that the artculatory loop system is “involved in some process of rehearsal, usually via sub-vocal speech, to maintain the memory trace.” The visuo-spatial scratch pad is the working memory component that you might use when you mentally rotate an object or even examine an object in your mind. For example, if I give you a picture of a room and have you stare at it for a few minutes, then I ask you to imagine the picture, you probably could. To do this, you are using your visuo-spatial scratch pad.

The existence of these systems is supported by a variety of experiments. Regarding the articulatory loop, there are many sources of evidence cited by Badelley, but I find the articulatory suppression literature most interesting. If subjects are given a list of words to remember and forced “to articulate repeatedly some irrelevant item such as the word the, suppression of their natural rehearsal mechanism reduces the number of words they can remember.” Basically, when not allowed to rehearse the information in our articulatory loop (because you were forced to repeat the word the), our memory abilities decrease.

As evidence for the visuo-spatial scratch pad, Baddeley discusses an experiment conducted by Stephen Kosselyn where subjects had to memorize a picture of a boat. “Kosselyn showed that a subject who had just responded to question about the stern of the boat took longer to respond to a question about the bow then one who had just responded to a question about the posthole. It was as if the subject were taking time to scan across the boat, and the greater the distance that had to be scanned the longer it took to respond” (Baddeley, 1984). It was as if subjects had the memory of the boat (stored as an image) and scanned it from one side to the next to be able to properly answer the question.

Our visuo-spatial scratch pad may be involved in many processes. Baddeley says that image-able words are easier to remember than those that are not image-able. This seems to tie with observations of children learning language. “… it seems easier to learn concrete concepts such as building, animal, or face than more abstract concepts such as twoness or roundness.”

Ok, now for tying this to VARK. VARK theories are based on separate processing via modalities (visual, auditory, reading, and kinesthetic). Could the articulatory loop be of service to the auditory and reading processors? Could the visuo-spatial scratch pad be of service to the visual processors? Maybe these working memory systems are a part of the reason why some people are V learners (according to VARK) and others are not. For example, one might be able to argue that if one has a better developed visuo-spatial scratch pad, they are more likely to be successful as a visual learner. Is there any evidence provided for this in Baddeley’s book?

Well, Baddeley’s own view appears to be that these systems are not executing critical thinking, but that they are simply “slave systems” of a central executive. He discusses research where one is given a task that leads to yes or no answers, but it is entirely dependent upon the visuo-spatial scratch pad. If you have the subject respond by speaking the yes or no answers, there is minimal interference between their answers and the task itself. If you have them point to the word yes or no (which may require more from the visuo-spatial scratch pad than a verbal response), there is some interference. Also, Baddeley discusses other research that relies primarily on the articulatory loop system and when asked to response by pointing to an answer (which is a spatial response), minimal interference is observed. When the same task is done with subjects being asked to vocalize a yes or no response, there is some interference observed. Thus, the articulatory loop and visuo-spatial scratch pad seem to be sub-systems of a larger “central executive.” In the majority of people, these sub-systems can work together effectively and Baddeley might argue that the individual differences might be found in the “central executive” and not in the individual working memory systems.

There is not much more to say that is too concretely tied to VARK. When discussing the visuo-spatial scratch pad, Baddeley says that the nature of the visuo-spatial scratch pad is “spatial in nature rather than visual.” For example, blind individuals have a concept of space and thus would use their visuo-spatial scratch pad for many non-visual things. This would argue against using the visuo-spatial scratch pad as a homolog for the V learners.

To finish up my Baddeley posts, I have one final comment to make. The last chapter in his book is titled “Improving your memory.” Here are the subheadings throughout: Everyday remembering, Demands on Memory, Visual Imagery Mnemonics, Verbal Mnemonics, Ritual and Oral Tradition, Memory Aids, Improving your Memory, Attention and Interest, Organization, Practice, Conclusion. Not one of these sections addresses individual differences between modality preferences and ability to learn the material.

In conclusion, I am disappointed with this particular citation from the VARK bibliography. It does not appear to provide any real support of VARK theories.

Baddeley, A. (1984). Your Memory: A User’s Guide, England: Penguin.

Baddeley AD, Hitch, GJ. (1974). Working Memory. In: The Psychology of Learning and Motivation¸Vol 8. Bower, GA (Ed). New York, Academic Press: pp. 47-90.


Tuesday, January 10, 2012

Memory and VARK Part 3: Semantic Memory


For my third post regarding the VARK citation of Alan Baddeley’s 1984 book, I will delve into semantic memory research (See my previous posts for why I am writing about Baddeley at all). Semantic memory involves storing the concepts and information that are necessary for the understanding of ideas and the meaning of whatever you are trying to remember. One of the central tenants of learning and memory that is discussed in many introductory psychology texts is that it is easier to remember the meaning of a particular word (a semantic memory) rather than the font and color in which they were presented (a so called visual memory) (Myers, 2006).

Baddeley goes through a significant discussion of semantic memory research; however, I believe the most relevant portion for my examination of the VARK sources is when Baddeley begins to probe into the nature of what a semantic memory is. He examines the role of language in semantic memories followed by a discussion of the role of visual images in semantic memories.

So, what is the nature of the semantic memory? How are concepts, ideas, and other important pieces of information that allow us to understand the world around us stored? Does the sensory modality that was present at the time of encoding play a role in the storage and retrieval of that memory?

According to Baddeley, “…semantics has been studied primarily by linguists or psycholinguists, and hence the greatest emphasis on meaning has been in relation to language.”

There are two main theories presented in the book regarding the relationship between language, semantics, and memory. One theory regarding the importance of language in meaning is the linguistic relativity hypothesis, initially proposed by Benjamin Lee Whorf. According to Baddeley, “Whorf argues that language is not simply a way of expressing your view of the world but that language itself determines this view.” One example that many are familiar with is the idea that Eskimos have many words for describing snow. As someone that lived in California for my entire life, I have two main words that come to my mind when I think of snow: white and cold. If given a piece of snow to examine, it would not be hard to imagine that an Eskimo would notice more details and probably remember them better than I would.

One interesting example that supports the Whorfian hypothesis involves comparing Korean and English speakers. When Korean speakers are discussing putting something into something else, they distinguish between loose and tight fits. English speakers do not do this. According to the linguistic relativity hypothesis, this would lead to differing perceptions at times and possibly a different way of understanding the world.

“To test whether these cross-linguistic differences are reflected in the way English and Korean speakers represent spatial relations, McDonough et al. (2000) showed scenes involving tight or loose fit to Korean and English speaking adults. After they had seen a few examples of either tight fit or loose fit, the subjects were shown an example of tight fit on one screen, and an example of loose fit on another. While Korean speaking adults looked longer at the kind of spatial relation they had just been familiarized with, English speakers did not distinguish between the tight and loose fit scenes, looking equally long at the familiar and novel scenes. Further, when given several examples of tight fit and one example of loose fit (or vice versa), Korean adults could easily pick out the odd picture, but English speakers could not.” (Boroditsky, 2003)

However, according to Boroditsky (2003), the Whorphian view has fallen out of mainstream psychological thought. The alternative view is that language may simply follow perception. Maybe the Eskimo has so many words to describe snow because of their frequent and varying perceptions of snow. Whorf believed that the Eskimo’s words led to their perceptual capabilities with snow and the alternative viewpoint is that the perceptions lead to the development of language. Eleanor Rosch’s work with the Dani tribe provides support for the alternative hypothesis. Apparently, the Dani have no words for specific colors, but instead of words for dark and light. Rosch found that the Dani could still discriminate between typical colors (red, green, blue, yellow) and atypical colors (periwinkle etc) (Rosch (1977) as cited in Baddeley(1984)). “Despite having no labels for red, green, and yellow, the Dani found them easy colours to handle, suggesting that language is based on perception, not the reverse.” (Baddeley, 1984).

Now, I admit that a discussion of linguistic relativity is a bit of a digression, but I will do my best to relate some of this to VARK in a bit. Bear with me while I move on to the discussion of visual images in semantic memories. It should be pretty obvious that various senses can play a role in semantic memories- without having words for it, I can appreciate and examine the details of various paintings (something with a visual component), music (something with an auditory component), and even food (something with a gustatory component). Think about the difference between two of your favorite painters. What do you like more about one or the other? Could you tell one apart from the other? What about two of your favorite musicians?  Can you easily put the differences between the two into words? Many people say something like “I don’t know why I like it, but I just do.” Or, “I’m not sure how I know this is -insert band name here- but it just sounds like them.” Of course, if you are an artist or a musician, you probably can go into the details using words, but that would be the exception here and not the rule.

In my absolute favorite experiment from this book, Baddeley discusses Ian Moar’s mental triangulation experiment. In the experiment, Moar examined the mental maps of housewives from Glasgow and housewives from Cambridge. The result of Moar’s experiment is shown below. Notice that the Glasgow housewives exaggerate the size of Scotland, relative to England and the Cambridge housewives exaggerate the size of England relative to Scotland.
Here is what the real map looks like:
Baddeley (1984)

And here are what the Cambridge (left) and Glasgow housewives (right) came up with:


Baddeley (1984)
What is the point of this experiment? Aside from the obvious perceptual differences between the two groups, Baddeley uses the concept of mental maps as an example of something semantic that is probably not entirely represented linguistically. It is not a huge stretch to imagine that there is some visual imagery going on here.

“Is it possible then that semantic concepts are stored as images? There is no doubt that visual or spatial characteristics can be important. One might for example have a concept of all round things or red things, but it is much less easy to argue that a concept such as justice of guilt is primarily stored in terms of its visual characteristics. Of course one can come up with visual images that might in some sense represent justice, but such images would be of very little assistance in deciding whether justice had been done in a particular court judgment. The most plausible assumption is probably that concepts are stored in some abstract code which may be translated into a verbal or linguistic form or into an image when the need arises…” (Baddeley, 1984)

Ok, so how does this tie to VARK? The language aspects discussed above could link to the A or R parts of the theory and the visual imagery discussed has obvious ties to the V component. The K component appears to be entirely ignored in this discussion; some may argue that the concept of a muscle or motor memory could be the needed tie for the K component. However, motor memories are probably not the same types of memories that have been discussed here (procedural vs semantic, explicit vs implicit).

For this part of Baddeley’s book to be particularly useful for VARK theorists, there should be some mention of individual differences. According to VARK, the person who prefers a visual modality presentation of information should do better later (for recall) when this preference is catered to. The same would be true for any of the other modality preferences (according to VARK).

Does the information discussed in the semantic memory portion of Baddeley’s book provide support either for or against this? In my opinion, the answer is somewhere between against this and neither.

In one experiment that directly contrasts two presentation modalities, subjects were told that they had to categorize objects. They received the object in a picture format or in a written format with their names printed out. Subjects were equally fast at categorizing both formats (Potter and Faulconer (1975) as cited in Baddeley(1984)).  In this experiment, no individual differences were discussed, so we are left not knowing whether there were subgroups that did better at one format or the other. Thus, there could have been subgroups (in this experiment) that were better at one or the other and when the data from each group was combined, the differences disappeared.

Furthermore, Baddeley cites Batlett (1968) concerning individual differences between visual imagery abilities and recall abilities. There do appear to be some individuals that are far superior in their ability to use visual imagery. However, for VARK to be supported, this would have to lead to recall differences later. Thus the “visual learner” not only needs to be better at the encoding/imaging portion, but also at the retrieval/recall portion. According to Baddeley, there is a “lack of a difference” between those that use visual imagery and those that use linguistic strategies. One must be careful when looking at this to reach strong conclusions one way or the other regarding VARK. VARK theories would propose the modality of presentation matters and this is something that is not discussed in this portion of the book. Thus, this lack of individual differences neither supports nor refutes VARK theory.

Theoretically, Baddeley supports a position that may argue against VARK proposed individual differences. He believes that the lack of differences between those that use visual imagery more and those that use linguistic methods are probably because regardless of how the information was encoded (through visual imagery or not), “since both draw on a single abstract store, the accuracy of what they recall will not differ” (Baddeley, 1984). Again though, one must be careful to reach a conclusion here. Without division into VARK subgroups, one could argue that no difference was found because the V learners were equally as able as the A and R learners.

So, my conclusions from this post are a bit mixed. There is no definitive evidence in favor or against VARK theories. Next up: Working Memory and VARK.

References

Baddeley, A. (1984). Your Memory: A User’s Guide, England: Penguin.

Boroditsky, L. (2003). Linguistic Relativity. In Nadel, L. (Ed.) Encyclopedia of Cognitive Science. MacMillan Press: London, UK, pages 917-921.

Myers, D. (2006). Psychology 8th ed. Worth Publishers.