In Making Memories, Change Is Good
Learning depends on the plasticity of the circuits in the brain--the ability of the neurons to make lasting changes in the efficiency of their synaptic transmission.
The brain can thus be said to store information in networks of modified synapses (the arrangement of which constitutes the information) and to retrieve this information by activating these networks.
Our understanding of the rules that govern association and the networking of neurons goes back to the groundbreaking work done by Donald Hebb more than 50 years ago. Hebb had an intuition that if two neurons are active at the same time, the synapses between them are strengthened. This hypothesis inspired many researchers, and the first mechanism supporting it, long-term potentiation (LTP), was discovered in the early 1970s.
The neurons involved in establishing a network must already be connected by synapses in order for these synapses to be strengthened or weakened. Networks are thus fashioned out of pre-existing “wiring.” Some of these pre-wired networks, such as those in the hippocampus, play a key role in the formation of memories.
Montreal Neurological Institute
Having a word “at the tip of your tongue” is a familiar but frustrating sensation. There it is, not very far, you know it, you can feel it, but you can’t find it! To make matters worse, very often another word keeps popping into your mind—you know it’s not the right one, but it keeps getting in the way so that you can’t find the one you’re looking for.