Wrapping up things related to working memeory

The new definition of working memory

In his seminar work on the capacity differences of individual working memory, Carpenter (Just & Carpenter, 1992) redefines its concept by borrowing a computational theory. They posit that both information restoring and processing are supported by the very same property named “Activation”.

When we are taking in new information from computations, each element is associated with an activation level. The element can be a word, sentence or a physical object such as a cat.

During the comprehension, only the element whose activation level exceeds the threshold value can enter working memory; in other words, not all the candidates are able to be further processed by brain even it is well retrieved from long-term memory.

However, people differ from each other with respect to their work memory capacity. In this case, which is seen as the total amount of activation level that the system can sustain.

Therefore, if at one time, the sum is about to go beyond the system limitation, certain chunk of old information must be de-allocated in order to accommodate more incoming data and computations.

Serving as one of fundamental concepts in cognitive science, we often find it in other literature.

Complementary learning systems

The hippocampal (HC) systems will be active in receiving information and temporally restoring the information, which means that the novel material cannot be truly learned immediately.

The neocortical systems will incorporate the new information gradually, as any quick absorption could be detrimental to existing structures of knowledge. 

The novel input need to go through various consolidation stages to obtain a membership from neocortical systems. Appropriate external events can serve as good opportunities and will help adjust neocortical connections.

Usually, the incorporation of unfamiliar material is slow, especially for arbitrary and idiosyncratic materials. Thus, when the memory traces degrade with time passing by, it is possible to lose them before they can be built into the shared structures in neocortical systems.

The complementary learning systems are more related to information storage and maintenance than information processing.

However, the weight changes of neurological connections may also be bound with “activation”. Without appropriate activations, the connections are not re-constructed or even established.

Although McCelland (McCelland & McNaughton, 1995) does not explicitly mention how the incorporation rate is to do with working memory capacity, the concept of “learning rate” may be a potential factor affected by the level of activation.

Metaphor

Metaphor in linguistic practices is fairly common, if a person wants to express certain idea from utterances, the hearer often can detect the meaning rather than the literal meaning of sentences.

If “S is P” actually refers to “S is R”, the comparison theory attempts to address the question of “how can we compute the potential value of R”; on the other hand, the interaction theory tries to look into the range restriction for R’s value by referencing the relationship between S and P.

To make this communication possible, the speaker and hearer must have something in common such as the principles to translate utterances.

Searles provides eight principles and suggests the methods by which the utterance of P term calls to mind the meaning of R term in the way pertaining to metaphor. For example, one principle is about human beings’ sensibility, and it is applicable for people from multiple cultures, as it is naturally determined.

From the perspective of working memory capacity, the duty to locate possible links between S and P or narrow the scope of R values heavily rely on activation for each property.

I maintain that the task to interpret metaphor is less like to challenge us in that there are normally three base elements to begin with, unless the range of R is quite large, or the “overlapping” attributes of S and P are too many.

In fact, an interesting question here is that: which principles consume more resources in working memory. The seemly more complex principle is not necessarily the one that requests a larger “brain”; it also depends on other constructs such as hearer’s knowledge base related to a specific domain.

Categorical Perception

The interplays between perceptual information and high-level knowledge of a particular object are another universal cognitive process. There are basically four rules that people use to group object.

While prototypes allow us to bring in more attributes to formulate semi-stereotypical representations, the exemplar models are stored stably in the memory, and they appear in a highly-abstracted form.

The process of establishing prototypes and exemplar sees the differences in the light of McCelland’s theory on complementary learning systems. Specifically, to build a new prototype may take a longer time than modeling an exemplar, as the former has to undergo a systematic procedure to live within existing structures that is shaped based on other surviving prototypes.

From the standpoint of working memory, it should work well to predict the efficiency of categorizing a perceived object.

Nevertheless, it may not directly determine how soon the new token will reach neocortical systems.

In the context of metaphor, in addition to referencing currently stored categories for the purpose of producing the metaphorical meanings of the utterance, we can also use the outcomes to re-categorize an object.

Cognitive Breakdowns

The cognitive breakdowns appear in multiple forms; for example, the loss of balance, the difficulty to focus, or the lack of reasoning capabilities.

Working memory is one major component being affected, for instance, some patients need to consistently re-chunk information in order to continue searching for the answer to a simple inquiry.

If the brain sees too much cognitive load, certain part of it will cease functioning. From that perspective, a wise usage of limited working memory resources is recommended for pertaining subjects.

The Representation of Personality in the Affective Reasoner

The situation is presented in frames, and frame matching asks for sufficient resources from working memory.

The computations on situation frames are supposed to generate emotion. Working memory is crucial for instantiating this intensive process on left hemisphere (LHS).

The emotion is only available if over intensity threshold, which is determined by bindings on LHS. Working memory is attributable to the binding process.

Some Implications for Design
First, designers should realize that users have different ability to store and process information; thus they should not be self-centered as the solution provider.

Second, designers must avoid using a solution that is too novel; although it may surprise users for its creativity, it may damage existing usage patterns that the users hold for other tasks at that moment.

Third, providing a "buffer-zone" for chunking/rechunking is recommended, as well as “Recognize Rather Than Recall”. Methods such as those will reduce users’ cognitive load, thus decrement the chances of over-charging working memory.

Forth, metaphor is equally important in that it is relatively easier for users to figure out the underlying meaning of design elements such as button or a gesture.

Furthermore, the calling for “universal design” does not only apply to people with physical disabilities, but also patients with brain damages at various levels.

Last but not least, if by its definition, the title of “User Experience” caters to user’s emotion responses, designers are expected to understand a little bit about the principles of emotion generation.
 

(© 2012 Miaoqi Zhu)