The Working Memory Capacity (WMC) describes the size of the available cognitive workspace that holds the Mental Model(s).
The available size can vary from person to person and it can be grown through training.
High WMC is often associated with the ability to allocate (sufficient) attention and resist distractions.
At more length in my blog.
- Forgoughi, Malihi, Boehm-Davis 2016 - Working Memory Capacity and Errors Following Interruptions
- Dingfelder 2005 - A workout for working memory