How plastic is the brain? What is the maximum amount of synapses? What processes (if any) increase synapse amount? What are some of the advantages of having more or less synapses?

  • $\begingroup$ Age is a big factor of course. AFAIK, plasticity declines monotonically (i.e., maybe not steadily, but it never increases) from birth to death. This has a lot to do with sensitive periods in development (e.g., the best time to learn a second language is ASAP, especially if you're not an adult yet) and cognitive decline (e.g., why old dogs don't learn new tricks), and may even have something to do with the relationships between age and conservatism and traditionalism. Much of the developmental process is one of pruning connections and reinforcing those most used, which leads to rigidity/habits. $\endgroup$ – Nick Stauner Jan 29 '14 at 16:08
  • $\begingroup$ You might be interested in the various segments of Scientific American Frontiers' Changing Your Mind. Quite a wide variety of topics in plasticity covered there. $\endgroup$ – Nick Stauner Jan 29 '14 at 16:14