Synapses and Sea Slugs


The sea slug is a one of the simplest animals known to be capable of learning. Ground-breaking research by Nobel Prize-winning neuropsychiatrist Eric Kandel used the sea slug to help us understand how the brain changes during the learning process.

What is Learning?

Learning involves alterations in the strength of communication between nerve cells. In humans, putting information into long-term memory changes the brain's structure. The number and percentage of active synapses changes with long-term memory learning, no matter what our age.

Filling our long-term, or explicit, memory consists of making new connections, as compared to the the implicit memory, which does not require conscious recollection. The implicit memory holds procedures and habits, like driving a car, which requires little contemplation once we've gotten the hang of it.

Speaking of habits, absorption of information in today's culture has been called "power-skimming." As you can imagine, this is not optimal for getting new information into long-term memory, where we can muse upon its meaning. We're literally skimming the surface.

By power skimming, we do not allow time for the crisscross of connections that promote joyful revelations and intuitive understanding. When was the last time you made a completely new connection to something, as opposed to following someone's suggested link in an internet article?

Novel Discoveries Keep Us Young

The Feldenkrais Method is as opposed to power skimming as you can get. Based on awareness of sensory feedback, Feldenkrais leads us away from the mechanical process of driving a car and towards new neural connections. Starting from the hum-drum of daily habits and moving toward that joyful sense of revelation when we make a novel discovery, Feldenkrais helps us realize that the arm is, in fact, related to the middle of the spine, and the hip joint affects the upper ribs, and the ankle movement improves the low back.

These revelations keep our minds and bodies young as we continually grow new connections. The sea slug had it right: Kandel observed that one of its neurons had 1,300 synapses. Of those 1,300 synapses, 40% were busy. The rest were resting. However, after the slug learned something in its long-term memory, 1,400 new synapses grew on that neuron, bringing the total to 2,700. And now 60% of them were busy!

Personally, I stand in support of the sea slug, the anti-skimmer, the deep thinker.