Critical periods: Understanding the mechanism for developing intelligence

The always-excellent Chris Chatham has a thoughtful analysis of the computational model of critical periods of development. This is the idea that there are certain periods during which we are primed to learn particular things. It can explain how we learn language, or learn to walk, or why mathematicians nearly all seem to be child prodigies.

The next phase in the study of critical periods, Chatham argues, is uncovering the mechanism by which they operate. How, exactly, do children learn language at such an astonishing rate, while teaching them to hold a knife and fork properly seems an epochal struggle? One promising way to explain these things is to use a computational model.

Computational simulations of critical or sensitive periods force theorists to become explicit about the precise nature of the representations in that problem domain or modality, and how those representations may change with age. Computational models also require that theorists indicate the exact kind of "input" required for a developing system to illustrate the critical period effect, as well as the frequencies with which those inputs are encountered.