more on the quartz paper

Section 3:
- present a behavioral systems model that regards the brain as a hierarchical control structure, where this hierarchical
organization is evident both developmentally and evolutionarily. This behavioral systems model places a premium on the complex interaction between developmental mechanisms and a structured environment
- highly conserved nervous system developmental mechanisms suggests that nervous systems, despite their apparent diversity, share a deep structure, or common design principles, just as the fact that two million distinct species share only 35 major body plans suggest that body plans share many common design principles
- At virtually all levels of the human nervous system, for example, reward systems can be found that play a central role in
goal-directed behavior (Schultz, 2000)
- Rather than simply carrying information regarding reward, it appears that octopamine signals information regarding prediction errors. (bumblebee)
- A system that learns through prediction learning need not have the path from goal to reward specified, in contrast to fixed behavioral patterns, such as stimulus-response learning. Instead, the path from goals to rewards may be left open and discoverable via learning, resulting in flexible action.
- in monkeys, Schultz also found dopamine reward signals that code prediction errors

midbrain dopamine system (old) projects to (new) dorsolateral prefrontal, premotor, and parietal cortex, ... structures implicated in crucial components of human cognition, particularly social cognition and theory of mind (Stone et al., 1998), symbolic learning (Deacon, 1997), representations of self (Craik et al., 1999), and executive function and behavioral inhibition ... these structures constitute a hierarchically organized control structure, where additional layers of control have been added to the evolutionarily conserved dopamine system and where this hierarchical organization is evident developmentally as well.

dopamine connected to all kinds of abilities involving the frontal cortex, and into adolescence, behaviour becomes increasingly mediated by frontal regions... the brain keeps developing until quite late.

Although there is strong evidence that an intact dopamine system is necessary for the developmental emergence of prefrontal functions, a largely unresolved question concerns the specific nature of this developmental link. One particularly intriguing possibility is that the dopamine signal serves as a learning signal that guides the construction of prefrontal structures during development.

The developmental link between the midbrain dopamine system and prefrontal structures suggests that an explicit account of the developmental trajectory of cognitive skills is necessary; an account based on innately-specified modules is inadequate.

neural constructivism whereby the functional properties of cortex are built from the dynamic interaction between neural growth mechanisms and environmentally-derived neural activity, acting hierarchically at the regional level and with high specificity at the cellular level (Quartz & Sejnowski, 1997; Quartz, 1999)

neural development during the acquisition of major cognitive skills is best characterized as a progressive construction of neural structures, in which environmentally-derived activity plays a role in the construction of neural circuits.

There is now good evidence to indicate that one component of social competence, theory of mind, depends at least in part on the appropriate social exposure for its development, as many deaf children show delays on theory of mind tasks