The mind's whiteboard
Holding a phone number while someone talks to you: that small whiteboard in the head is working memory.
You hold a few things at once: lights, cells, letters: and they fade fast.
Repeating, grouping, and picturing keep them alive longer.
Spans stretch with practice at the edge of your limit, which is where our ladder keeps you.
Then and now
The span and n-back tasks moved from paper labs into brain scanners; they are the working-memory probes modern neuroscience runs.
Baddeley, A. D. and Hitch, G. (1974)
Where it began“Working memory”
The Psychology of Learning and Motivation, Vol. 8, 47-89
Proposed the working-memory model: a small active workspace, separate from long-term memory, that holds and manipulates information.
Kirchner, W. K. (1958)
Where it began“Age differences in short-term retention of rapidly changing information”
Journal of Experimental Psychology, 55, 352-358
Introduced the n-back task: respond when the current item matches the one n steps back, the classic updating test.
Owen, A. M., McMillan, K. M., Laird, A. R. and Bullmore, E. (2005)
State of the art“N-back working memory paradigm: A meta-analysis of normative functional neuroimaging studies”
Human Brain Mapping, 25(1), 46-59
A meta-analysis of brain-imaging studies: the 1958 n-back task is the standard probe of working memory in modern neuroscience.
What we do and do not claim
Practice improves performance on span tasks like these. Claims that this raises IQ are contested, so we never make them.