Along with being short changed in the name, working memory is sometimes short changed in analogies too. It used to happen more often, but not so much any more.
It used to be compared to the RAM – random access memory – in digital computers, misleading because its capacity is nowhere near the amount of RAM you’d find in a typical computer. Rather than megabytes and gigabytes, working memory capacity is measured in items: typically 4-5 units of information at any given time.
It’s hard to imagine how something this limited can be so powerful, as we’ll see.
For now, think of working memory capacity as analogous to registers onboard the CPU in a digital computer. It’s a big simplification, but one that’ll helps us along.
So, what is a register onboard a CPU?
A digital computer has permanent storage, i.e., disk, and temporary storage, i.e., RAM. It also has a small amount of memory, known as registers – only a handful of registers – directly onboard the CPU. The CPU operates on the registers, and not directly on the RAM. It loads data from RAM into registers, operates on the registers, then writes the results back to RAM.
Working memory is analogous to registers onboard a CPU in that:
(a) it is very limited in capacity, and
(b) it’s closely connected with the manipulation of information.
It’s what we use to hold on to information while we process it, i.e., think about it.
The analogy is instructive, because we usually don’t appreciate just how scarce and limiting this resource is, and how broad and consequential its effects are on our lives, success and happiness.
It’s also directly implicated in intelligence.
