The tradeoff between stability and plasticity may also explain why the brain uses two information stores. Like information in RAM, patterns of spiking change quickly and are suited to active manipulation of information during perception and thought. Because they are easily disturbed by new perceptions and thoughts, patterns of spiking are useful on

A second factor is repetition.

every stream has a bed.

This tradeoff has been named the “stability–plasticity dilemma”

If two neurons are repeatedly activated simultaneously, then the connections between them are strengthened in both directions.

Neural Darwinism is still speculative.

One self changes rapidly from moment to moment, becoming angry and then cheering up, thinking about the meaning of life and then the household chores, watching the leaves fall outside and then the football game on television. This self is the one intertwined with consciousness. Its protean nature derives from the rapidly changing patterns of neural

The other self is much more stable. It retains memories from childhood over an entire lifetime. Its nature—what we think of as personality—is largely constant, a fact that comforts family and friends.

most mental functions require the cooperation of multiple cortical areas, and most cortical areas participate in multiple mental functions. This makes it problematic to use functional criteria to define cortical areas. The right strategy is to identify the areas by structural criteria and then understand how the interactions between areas give rise