Sunday, September 26, 2010

Earliest Instance of the Cortical Volume Hypothesis?

More good stuff from Gomulicki's article on the history and status of the theory of the memory trace. In this passage, Gomulicki discusses the hypothesis that intelligence depends on the size of your cortex: 

"Aristotle's view that the heart was the seat of mental processes, including memory, was short-lived. It was, in fact, overthrown by his own grandson, Erasistratus (c. 310-250 B.C.) and Herophilus (335-280 B.C.), who, working together carried out what were probably the first dissections of the human brain and studies of the sensory and motor systems. They accepted the view that the heart was the seat of the 'vital spirits' (pneuma zolicon), but held that the 'animal spirits' (pneuma psychicon)--the physical mediators of mental processes--were located in the nervous system, and in particular in the brain. They even had the astuteness to attribute the superior intelligence of man as compared with other animals to the greater development of the convolutions in man, though this view was only a deduction from a quantitative correlation for which they did not attempt a functional explanation." (Gomulicki p. 2) ...Basically, it didn't occur to them that the convolutions made it possible to pack a large cortical sheet into the human skull...If I remember right, Galen thought that the size of a donkey's brain and the stupidity of the donkey served as an adequate counter-example to the notion that brain size effects intelligence. Given the later authority conferred on Galen's thought, it's no surprise that Erasistratus and Herophilus' conjecture would fail to take hold.