A meaty post on Reworking Working Memory at Developing Intelligence.  Not surprisingly, the division between short-term (“working”) memory and long-term memory apparently isn’t as neat as many “how to train” articles imply.

One of those “hadn’t-thought-about-that” implications: one function of working memory is to actively maintain important information in the face of interference.  As I read that, working memory in a sense is trying to concentrate on what’s important even as new information streams in.

The blog post comments on an article in Psychological Review by Unsworth and Engle, who suggest working memory has two parts:

• A primary memory system to actively maintain information, operating with a small but dynamic capacity, and
• A secondary memory system to store items displaced from primary memory, along with context to use as a retrieval cue

Developing Intelligence’s Chris Chatham  says that the primary and secondard aspects of working memory appear to be independent factors affecting working memory as a whole.

…As I went from one article to another, I came across a suggestion that people with lesser working-memory capacity may do more poorly at sorting out key aspects and thus store more information in long-term memory than people with a higher working-memory capacity.  Presumably the latter group stores the key retrieval information.  Until I trip over that link again, though, “I recall reading this” will have to do.