If someone who had low working memory scores as a child suddenly sees in improvement in attention as he grows older, does his ability to hold and manipulate information also increase? Or does attention serve as bottleneck score for such working memory exams?
Also, is there a way for someone to assess his WM at home?
Engle has published extensive papers about this topic and if you are interested I suggest looking him up.
In 2001 Kane, Bleckley, Conway, & Engle (In Engle, 2002) attempted to directly measure the relationship between WM and executive attention, and conclude that that the underlying factor responsible for the relationship between measures of WM capacity and performance on higher-order cognitive tasks is a domain-free executive-attention system.
Although individuals possessing different WM capacities will show differences in number of items stored in a variety of memory tasks, this is a result of differing ability to maintain and inhibit information, particularly in the face of distraction and interference. Only when the context makes it difficult to maintain the appropriate task goal do people with high WM spans perform better than people with low WM spans.
In 2003 he found that:
Individual differences in working-memory (WM) capacity predicted performance on the Stroop task in 5 experiments, indicating the importance of executive control and goal maintenance to selective attention
In my opinion the two are obviously linked however it would be difficult to infer causality or direction in the relationship. It would make sense that if your attention improves your working memory would also improve, however it's hard to say if one causes the other or if they are intrinsically linked and would just both increase at the same time.
In terms of measuring WM at home here is a link to an n-back test which I think will be fairly easy to do at home:
http://cognitivefun.net/test/4
The n-back task requires participants to decide whether each stimulus in a sequence matches the one that appeared n items ago. N-back has become a standard measure for WMC, however treat results with a pinch of salt as Kane et al (2007) have called it's validity into question.
References:
Working memory (WM) and attention are interrelated, as a precondition for WM to operate is attention. In addition to attention we need awareness. The general view is that WM is explicit - conscious - and never implicit. The key difference between the term "working memory" and the older term "short-term memory", is precisely highlighting the role of attention and updating in memory.
To answer your question, we should consider that there are different types of attention. We can distinguish between momentary "spot-light" attention (or we could speak of "selective attention") and sustained attention (vigilance). In addition to WM training, there are training tasks for improving sustained attention. These are distinct put overlapping domains.
Unfortunately, the n-back task that was recommend in another answer varies due to different designs of the task and a score is therefore not easily comparable to other n-back scores, but for the same task only. One important distinction can be made between tasks that are designed for testing and tasks that are designed for training. In training tasks you are supposed to change your score and these tasks are therefor not ideal for measurement, whereas test tasks should ideally be more robust to change.
There are some clinical tools that have been established for assessing short-term memory. These tasks include Raven's progressive matrices and the Corsi block task. The advantage of these tests is their comparability between individuals. A disadvantage is that they are rarely computerized and less accesible outside the neuropsychological community.
WM is a very broad and colorful concept. Maintaining and updating information are two separate aspects of WM. The first requires sustained attention, the second requires flexibility of thought. Traditionally, the upper limit of the capacity for a number of items is measured. This is equivalent to storage in short-term memory.
However, one further requirement for defining WM is the online manipulation of maintained items. The size of the short-term store - number of items - is just another index of WM performance, although it is still considered the gold standard. However, the score is heavily dependent on what task you choose.
As a student I am currently working on a classical working memory task for testing that runs in your browser. I hope to release it this year as open source. There is still much work to be done to give people at home the ability to test working memory.
Finally, motivation and working memory are strongly linked. Comparing yourself to your peers can reduce performance. It is therefore better to take a "master-oriented" approach and to compare your score with your previous scores.
