A visual tour of the clichéd ‘cogs in the brain’ image that seems to get attached to virtually every psychology article that isn’t published in a women’s magazine.
I’d be genuinely fascinated to know when this visual analogy first arose as you’d guess it’s a result of the computational model of the mind that arose with 50’s cognitive science.
But you never know (at least, not without a stiff dose of machine oil).
Link to never ending brain cogs.
Mind Hacks 
The earliest example close to this that I know of is Fritz Kahn’s industrial body: http://www.nlm.nih.gov/exhibition/dreamanatomy/da_visible_industrial.html . Not sure if that’s what you were looking for, but it’s pretty cool stuff.
Surely it looks more like a Babbage-computational than an electronic device? Even earlier,
“The Emperor Napoleon I, a chess player certainly of prominence and reportedly of ability, lost a chess game in 15 moves to a seeming thinking machine; a clockwork automaton known as ‘the Turk.’ Reports of the time say that Napoleon ‘angrily stalked from the room.’ ”
Wheels and cogs defined what mechanism meant, _up_to_ the mid-20th century, and in this case persist beyond it. As obsolete as the elliptical orbits in the Bohr atom, but what else are you gonna draw?
These days it would be better with electrical currents, as apparently the brain is “wired” to do things, even according to professional science websites.
It’s cog-nitive – geddit?
Isn’t it referencing the Leibniz remark from the Monadology?
I suspect it goes back much farther–to the Deistic idea of a clockwork universe and clockmaker God, which appears in Alexander Pope’s long poem An Essay on Man (ca. 1730)which includes images of creatures as cogs; and to the original idea of a computational engine (which surely preceded Babbage’s specific idea ca 1820; to the 18th century fascination with automatons, cf. http://www.fi.edu/learn/sci-tech/automaton/automaton.php?cts=instrumentation (and perhaps back to the Greeks and Romans who I think had such things; and simply to the origins of mechanistic analogies for living creatures.
The amount of images that have arranged the cogs so that they work against each other and can’t ever move is quite staggering.