last notes: page 32

How we learn

Neurons are the basic building blocks of our brain. They consist of an arm (axon) and legs (dendrites with cactus-like spines on them known as dendritic spines).
When we start learning anything in any form, neurons start finding each other, extending their axons to the spines of other neurons. When two neurons are close enough, a signal jumps over the empty space between them (synapse) from the axon of one neuron to the spine of the other. This is what generates a thought.
Learn it, link it: As a student continues learning, they keep strengthening the connections between their neurons. When a student is introduced to a new topic (e.g. in class), neurons’ begin to find one another. Once we start actively engaging with the material, we strengthen our links and move them to long-term memory. This is when we reach proficiency. Finally, engaging in varied forms of practice, can strengthen and even extend the neural circuits even more.

Long-term memory vs Working memory

Neural circuits that reside in long-term memory are physically present in the neocortex. But it takes a lot of time and practice before links can be formed in long-term memory.
When we start learning something new, we engage with it using our working memory. Working memory consists of short-term memory (e.g. a sentence that we just read) along with the ability to manipulate things in the short-term memory (e.g. reversing the sentence).
Working memory gives us the illusion that what we’ve learned is now in our mind. But it is only temporarily there. The best way to understand working memory is to think of an octopus juggling balls. Usually, we can only juggle 4 balls at a time. These balls bounce between the front and back of our brain as long as we keep a thought in working memory.
However, if we get distracted or try to juggle too many balls, we’ll struggle and loose those balls. This leads to a phenomenon where we think we have learnt something but even if we’re asked to explain it just a few seconds later, we might not be able to recall anything. Because we lost the thought from working memory and it was never moved to long-term memory.
This is what happens typically when students struggle during exams. Often, while studying, they simply glance through the material or keep re-reading or highlighting, looking at solutions to example problems, without ever actively working through the solution themselves, thus, never cementing the concepts in long-term memory.
Our brain has information storage capacity of 10^15 bytes. Typical lifetime = 10^9 seconds. Can dedicate 10^5 bytes for each second.
Links reinforced through varied practice find their way into long-term memory.
Working memory neurons are different (can’t hold information for long) from those of long-term memory (can hold information for a long period)

Race Car brains vs Hiker brains

Some people have a high capacity for working memory and are able to process whatever is being taught very quickly. Thus, reaching the end goal, i.e. the answer, very quickly. Others have a hiker brain where they take time to reach the finish line. Someone might be a hiker in a particular topic and a race car in another.
Having a race-car brain doesn’t automatically mean it is better. Although a racer reaches the finish line quickly, everything goes by in a blur. Whereas the hiker can enjoy every aspect of the ride because they move slowly, which might be considered deeper and richer.
Many great achievers actually have hiker brains and they tend to attribute their success to the fact that they were not geniuses and had to struggle their way to understand concepts during which they were able to find gaps and unjustified assumptions that others simply missed. They were also more flexible in their ways of thinking, quick to accept their mistakes and course correct. Unlike the geniuses who were used to being right and didn’t know how to accept their mistakes when they were incorrect.