The neural basis of cognitive development: A constructivist manifesto

Abstract

How do minds emerge from developing brains? According to “neural constructivism,” the representational features of cortex are built from the dynamic interaction between neural growth mechanisms and environmentally derived neural activity. Contrary to popular selectionist models that emphasize regressive mechanisms, the neurobiological evidence suggests that this growth is a progressive increase in the representational properties of cortex. The interaction between the environment and neural growth results in a flexible type of learning: “constructive learning” minimizes the need for prespecification in accordance with recent neurobiological evidence that the developing cerebral cortex is largely free of domain-specific structure. Instead, the representational properties of cortex are built by the nature of the problem domain confronting it. This uniquely powerful and general learning strategy undermines the central assumption of classical learnability theory, that the learning properties of a system can be deduced from a fixed computational architecture. Neural constructivism suggests that the evolutionary emergence of neocortex in mammals is a progression toward more flexible representational structures, in contrast to the popular view of cortical evolution as an increase in innate, specialized circuits. Human cortical postnatal development is also more extensive and protracted than generally supposed, suggesting that cortex has evolved so as to maximize the capacity of environmental structure to shape its structure and function through constructive learning.

Constructing an understanding of mind: The development of children's social understanding within social interaction

“…In connection with this, it is interesting to note a parallel "neuroconstructivist" movement focused on internal structures and mechanisms that attempts to chart a middle way between the extremes of nativism (too much prespecified structure) and empiricism (too little structure) to explain the development of higher-order capacities through the child's interaction with a progressively structured, even necessarily social environment (Elman et al 1996;Karmiloff-Smith 1998;Quartz & Sejnowsky 1997). Given the similarity of constructivist ambitions, there may be fruitful connections to exploit between these two programs.…”

A Generalized Selected Effects Theory of Function

“…For example, Purves et al (1996) and Quartz and Sejnowski (1997) Garson 2012 for further discussion). Those critics tend to think of neural selection as a "two-step" process in which, at birth there is a large number of synapses that get progressively whittled down in early development (e.g., Purves et al 1996, 461;Quartz and Sejnowski 1997, 539).…”

Neural tuning of human face processing

“…For example, a recent functional MRI study reported that visual representations of faces are "pruned back" during early childhood (14). Such purported explanations fail to account for the fact that the brain does not shrink during postnatal development but grows in size, and that the loss of synaptic connections is only one phenomenon in the context of several other mechanisms of selective synaptic growth and elaboration (15,16). In the present context, the lack of N170 tuning in congenital cataract participants would typically evoke a "pruning" explanation: a failure to eliminate incorrect synapses.…”