Working Memory and its Importance
The Importance of the Human Mind
With my background in Applied Cognition and Neuroscience, I have always been fascinated with how the human brain works, particularly memory. There are so many facets to the human brain and knowing even a little bit about it can help designers, developers and creators establish well built products.
As designers, our job is to have empathy. Understanding the human brain allows another dimension of integrating empathy to designs. During my time in school, there was a particular course called Memory that blew my mind. Although, I learned a great deal about memory in that course, what I learned in particular about working memory gave me another perspective as a designer.
What is Working Memory?
One of the founding fathers of cognitive psychology, George Miller along with Galanter, and Pribram coined the term working memory. Working memory is the cognitive system that holds and processes information. It is how the mind temporarily manipulates and stores information during tasks that require reasoning and thinking. Think of it as the brains very own sticky notes or task list, essentially memory that is being worked on in the moment. It differs from short term memory as it not only holds the information but processes it as well.
When do we use Working Memory?
Working memory is often correlated with fluid intelligence. Anything that has to do with planning, problem solving and reasoning involves working memory. The information processed comes from both the long term memory and the environment.
So when do you use your working memory?
- Any problem solving, such as math and word problems
- Following directions
- Dealing with more than one piece of information
- Tasks that require comprehension and learning
- Focusing or paying attention
Miller’s Law
Ever wondered why a phone number often looks this way, (817) 225- 3325?It feeds into Millers Law.
Millers Law or Millers magical number is the observation that an individual normally can retain or process only seven give or take two (7±2) items (chunks) of information in their correct serial-order, in his or her working memory(15 to 30 seconds duration) (Miller 1956).
Keep in mind that the number is more of an estimate not meant to be precise. An updated study by Nelson Cowan showcases the new magic number may be four. Below is an excerpt from Cowan’s study in regards to Miller’s number.
However, that number was meant more as a rough estimate and a rhetorical device than as a real capacity limit. Others have since suggested that there is a more precise capacity limit, but that it is only three to five chunks (Cowan 2000).
Just remember that an average person has a limited capacity of information they can hold in their working memory. A phone number along with the area code is a 10 item information that has been categorized into chunks so it can be easily remembered. If the phone number has more than 7 chunks it would be very difficult for an average person to remember.
How to incorporate Working Memory in Design
Knowing how working memory works and its limitations allows designers knowlege to create human centered interfaces. Design with the power of knowledge and empathy. Designer’s and those that create software need to be cognizant of the humans limitation and functionalities. Design to maximize the human strength and accommodate the human limitations.
Here are some things you can do to design with working memory in mind.
Categorization is key!
Miller’s law suggest that organizing information into higher abstract categories can optimize the user experience and help the working memory.
For example, trying to remember the following list of items can be difficult: pepperoni, sausage, olives, tomatoes, peppers, thin crust, deep dish and chicken
However, by organizing the items into categories it becomes easier to learn read and remember:
Crust: Deep dish, thin
Meat: Pepperoni, sausage, chicken
Vegetables: peppers, olives, tomatoes
Card sorting can be utilized to discover how people understand and categorize information. Optimal Workshop is a great tool to help with card sorting.
Check out usability.gov to learn of the various card sorting techniques.
Chunking
Organization into categories can sometimes lead to chunking. Chunking is a psychological process by which individual pieces of information are bound together into a meaningful whole (Neath & Surprenant, 2003).
There are several ways to chunk information. The technique you use to chunk will depend on the information you are chunking.
- Grouping
- Finding Patterns
- Organizing
Serial Positioning Affect
Serial positioning affect refers to our tendency to be able to recall the first and last items on a list better and the middle items worse.
As a designer you can take advantage of serial positioning by placing the most important information on the left and right. If it is in the list formation, place the most important items in the top and bottom.
Fun Fact:Primacy effect content may go into the long term memory by the time of recall where as recency effect is subjected to the short term memory. The tendency to recall earlier words is called the primacy effect; the tendency to recall the later words is called the recency effect.
Below is an excerpt from an experiment on the serial positioning affect by Bennet B Mudrock.
Murdock (1962)
Procedure
Murdock asked participants to learn a list of words that varied in length from 10 to 40 words and free recall them. Each word was presented for one to two seconds.
Results
He found that the probability of recalling any word depended on its position in the list (its serial position). Words presented either early in the list or at the end were more often recalled, but the ones in the middle were more often forgotten. This is known as serial position effect.
The improved recall of words at the beginning of the list is called the primary effect; that at the end of the list, the recency effect. This recency effect exists even when the list is lengthened to 40 words.
Conclusion
Murdock suggested that words early in the list were put into long term memory (primacy effect) because the person has time to rehearse each word acoustically. Words from the end of the list went into short term memory(recency effect) which can typically hold about 7 items.
Words in the middle of the list had been there too long to be held in short term memory (STM) (due to displacement) and not long enough to be put into long term memory (LTM). This is referred as a asymptote.
In a nutshell, when participants remember primary and recent information, it is thought that they are recalling information from two separate stores (STM and LTM).
Working Memory Assessment
A common test utilized to assess working memory is the N-Back Task. In short the N back task .
The N-Back Test was originally developed by Wayne Kirchner as a way to measure working memory. In this test, the subject is given a sequence of stimuli, shown in order. When the stimuli matches what was shown ‘n‘ steps before, the subject then presses ‘stop’.
The number ’n’ will increase, meaning that you need to remember more and more items as the game progresses.
Further Exploration
Test out your working memory through these various resources!
