>Are there other ideas present (or that could be explored) for a different core mechanism for learning? There is the predictive coding theory of neuron spiking

>Are there other ideas present (or that could be explored) for a different core mechanism for learning? There is the predictive coding theory of neuron spiking (review paper here: http://www.ncbi.nlm.nih.gov/pubmed/23177956 http://www.ncbi.nlm.nih.gov/pubmed/23177956), which says that human neurons fire to signal surprise. The neural networks is eventually slowly rewired so that inhibitory "predictive" signals successfully suppress excitatory "observation" signals, with a null-action indicating that the brain's model of the world remains largely correct. This is a very rough layperson's understanding, since I'm not a neuroscientist, so read the paper!