MONIAC is a collection of tanks, tubes, valves and gates through which coloured water can be pumped and is intended to represent the “economy” in operation and the effect of changing the various economic “levers” represented by the various paddles, gates and valves.
Even by looking at MONIAC (Monetary National Income Automatic Computer) not in operation I could see how it would work and how income is spent on taxes, savings and imports, and how demand is re-injected via exports, public spending and investment. From that point on economics a subject was clear to me.
Thomas West in his book “In the Mind's Eye” (Prometheus Books) describes the skills possessed by some dyslexics as visual/spatial rather than verbal skills, in the sense that people with these skills tend not to think in words but more in images.
Some people have the ability to construct mental models. Nikola Telsa is highly regarded amongst professional electrical engineers as the man who developed many of the concepts behind the electrical power systems we use today. For a time an employee of Thomas Edison, Telsa was dubbed by admirers as "the man who invented the twentieth century”1.

Imagine the power of this skill and the work that would be saved by not having to actually build a model like MONIAC until all the bugs have been worked out. Perhaps this is what Mr West is referring to when he talks about visual/spatial representations.
Certainly primitive man would have found such mental models particularly useful for diverse activities such as war craft, hunting, weather prediction, architecture, simple engineering, agriculture and so forth. In short this would be a real survival trait compared with fluency with numerical sequences or the ability to memorise by rote.
Memory based skills on the other hand would be of great use for people like medieval academic monks, shamans and those recording the oral history.
Part 2 of a 3 part series
Ⓒ Robert Gray 2007