“That structure was just guess work, but we seem to have guessed well.”

This interview with Alan Baddeley, one of the researchers responsible for the contemporary notion of “working memory,” is fantastic. I’m not up to speed on all the psych concepts yet, but there are a lot of juicy bits.

First, you can’t get into research like this any longer:

When I graduated I went to the States for a year hoping, when I returned, to do research on partial reinforcement in rats. But when I came back the whole behaviourist enterprise was largely in ruins. The big controversy between Hull and Tolman had apparently been abandoned as a draw and everybody moved on to do something else. On return, I didn’t have a PhD place, and the only job I could get was as a hospital porter and later as a secondary modern school teacher – with no training whatsoever! Then a job cropped up at the Medical Research Council Applied Psychology Unit in Cambridge. They had a project funded by the Post Office on the design of postal codes and so I started doing research on memory.

On his “guess work”:

I think what we did was to move away from the idea of a limited short-term memory that was largely verbal to something that was much broader, and that was essentially concerned with helping us cope with cognitive problems. So we moved from a simple verbal store to a three component store that was run by an attentional executive and that was assisted by a visual spatial storage system and a verbal storage system. That structure was just guess work, but we seem to have guessed well because the three components are still in there 30 odd years later – although now with a fourth component, the ‘episodic buffer’.

What if he had guessed something different, and if that different guess had held up decently? Psychology is at a local maximum, but it seems to me that there’s very reason to think that our current conception of the mind is at anywhere near a global maximum, the most natural and useful way of conceiving of things.

On that:

The basic model is not too hard to understand, but potentially it’s expandable. I think that’s why it’s survived.

Here is the context for their description of working memory, as distinctive from short-term memory:

I suppose the model came reasonably quickly. Graham and I got a three-year grant to look at the relationship between long- and short-term memory just at a time when people were abandoning the study of short-term memory because the concept was running into problems. One of the problems was that patients who seemed to have a very impaired short-term memory, with a digit span of only one or two, nevertheless could have preserved long-term memory. The problem is that short-term memory was assumed to be a crucial stage in feeding long-term memory, so such patients ought to have been amnesic as well. They were not. Similarly, if short-term memory acted as a working memory, the patients ought to be virtually demented because of problems with complex cognition. In fact they were fine. One of them worked as a secretary, another a taxi driver and one of them ran a shop. They had very specific deficits that were inconsistent with the old idea that short-term memory simply feeds long-term memory. So what we decided to do was to split short-term memory into various components, proposing a verbal component, a visual spatial one, and clearly it needed some sort of attentional controller. We reckoned these three were the minimum needed.

In other words, short-term memory was assumed to be unitary. Baddeley and Hitch figured that it could have three independent components. Since short-term memory was running into trouble, it sounds like they kind of rebranded it as working memory.

Are there other differences between short-term memory and working memory besides its multi-component nature? I think so, but I’m currently fuzzy on this. Another thing that I’ve read suggests that short-term memory was seen as just on the pathway to long-term memory, so it was essentially part of a memory-forming pathway. Working memory is supposed to play a broader range of roles…I’m confused on this, honestly.

Finally, here’s a solid interaction:

Your model with Graham Hitch has a central executive controlling ‘slave’ systems. People sometimes have a problem with the term ‘slave’?
This is presumably because people don’t like the idea of slavery.