The headline of a recent press release by the Ecole Polytechnique Fédérale de Lausanne about a recent paper in PNAS (Perin R., Berger T.K., & Markram H: A synaptic organizing principle for cortical neuronal groups, p, 108 (12); link will download a PDF.), reads “New evidence for innate ideas.” The kind of innate knowledge for which there is supposed to be new evidence is described as follows.
These clusters contain an estimated fifty neurons, on average. The scientists look at them as essential building blocks, which contain in themselves a kind of fundamental, innate knowledge – for example, representations of certain simple workings of the physical world. Acquired knowledge, such as memory, would involve combining these elementary building blocks at a higher level of the system. “This could explain why we all share similar perceptions of physical reality, while our memories reflect our individual experience”, explains Markram.
The “clusters” are “pyramidal neurons in the neocortex,” according to the article. The argument that the way these neurons develop is evidence that there are innate ideas is described.
When the scientists tested in vitro neuronal circuits from different rats, they all presented very similar characteristics. If the circuits had only been formed from the experiences lived by the different animals, the values should have diverged considerably from one individual to the next. Thus, the neuronal connectivity must in some way have been programmed in advance.
The argument is that we should expect different neuron clusters in different rats, because the rats had different experiences as the neurons developed. But what’s seen is that the neuron clusters do not differ from one another.
Hang on. Presumably we all have more or less the same “representations of certain simple workings of the physical world,” because everyone lives in three spatial dimensions and one temporal dimension, which always moves in the same direction; and the fundamental physical properties of medium-sized and large objects are the same everywhere. If something really big falls on something really small, the small thing will be crushed. I imagine the same is true for rats. I would think that rats live in a world poorer in diversity than we do. So it should be no surprise that the neurons that develop in response to the “simple workings of the physical world” develop the same in all the rats and probably all (normal) people as well.
The remarks about Locke are false, at least, within the discipline of philosophy. “Since John Lock [sic], about 400 years ago, research into how the brain learns and remembers has been guided by the belief that we start from a clean slate.” This is not true. Kant quite clearly indicated that he believed that there was some knowledge that we could not have learned through the five senses, but that we possess nonetheless. Querying the Stanford Internet Encyclopedia of Philosophy for nativism is a good place to start learning about the veritable flood of work on this subject in many disciplines.
Another point that’s important is that it most certainly does not follow from the claim that a trait is inherited that it is innate. “Innate” is fatally ambiguous, and should probably be retired. Paul Griffiths argues conclusively for this in a paper that’s available online (this links to a PDF file which will be downloaded immediately upon following it.).