On learning

Trevor Hartman

It wasn't until I was well into my twenties that I learned how to really learn. And it was only by learning many hard concepts related to programming on my own that I observed and proved what worked. It unlocked a sort of power. Realizing how to learn nearly any hard topic is an incredibly useful skill. I found that efficient learning techniques had nothing to do with typical class structures found in high school or university settings, which had previously drained my desire to learn. In that regard, the subject of learning, or learning how to learn is something I find very interesting and think about a fair amount, so when I found the Learning How to Learn class on Coursera by Dr. Barbara Oakley, Dr. Terrence Sejnowski I immediately signed up. Here are my notes and observations gained from the class.

Modes

There are two primary modes of thought:

  1. Focused: this mode is engaged when you're doing something you already know how to do, quickly accessing the learned connections in your brain. The connections are very tightly spaced in the prefrontal cortex.

  2. Diffuse: this mode is for open minded thought that allows you to make new connections in your brain. You can think of this mode as exercising your brain muscle and letting your mind wonder. Edison and Dalí are famous examples of thinkers who practiced the diffuse mode: they would hold something in their hands while day-dreaming until dozing off to sleep at which point they'd drop the object and wake themselves back up in order to take what they learned and apply it in a focused mode. Diffuse mode relies on loosely spaced connections, and is engaged by drifting off to sleep and excercise.

Brain facts

  • The brain is the most complex device in the known universe
  • Acquiring skills takes years and years of practice (e.g. math, chess)
  • We are not consciously aware of how our brains work
  • There are 1015 (a million billion) synapses in the brain
  • Brain connectivity is dynamic even after it matures
  • Our brains develop new synapses while we sleep

Techniques

  • Pomodoro: set a 25 minute timer to focus on a specific task or goal and reward yourself when you're done (e.g. read the Internet, get a coffee). Use this to build the neural patterns you need to learn new concepts. It helps to actually write your goal down. There are a few terminal and OS X apps that can help. Writing down the goal helps combat initial skatterbrain tendencies, which sometimes require continual re-focusing at first.

  • Translation and rewriting: when I read academic papers, I rarely understand the cryptic math syntax. A good way to break through is to translate the syntax to something you do understand. For me, this means Haskell. Then rewrite the plain text sections in your own words (tip: try writing a blog post that sumarizes the paper). You can't help but internalize the concepts when you do this.

  • Handwritten notes: when learning a library of any complexity, simply reading the source doesn't always help. You need to run it and observe the values in context and the execution path. A debugger can help here. While you're doing this, take handwriten notes on important functions and variable values. Sketch out an execution tree. You may never refer to these notes again, but the mere act of physically writing them makes abstract concepts more concrete.

Abstract Concepts

Abstract concepts in particular require much more practice to create concrete neural thought patterns. The initial neural pattern is there but it is very weak. When you solve a problem again you strengthen that pattern. When you've done it so many times you have it down, the thought pattern is very strong.

Study and focus intently, then take a break to allow the brain's diffuse mode to help you out with your conceptual understanding. "Neural mortar has a chance to dry".

Memory

Long term memory vs working memory.

Working memory (prefrontal cortex) is what you're currently focusing and working on. It can hold about 4 chunks of information. We naturally group things into chunks (e.g. phone numbers). Working memory is like a blackboard.

Long term memory is like a storage warehouse, spread over different areas of the brain. To store something in long term memory you need to revisit it several times. We can store billions of items, but they can bury each other. Spaced repetition is one technique of storing something in long term memory: repeat something over a number of days.

Sleeping

Being awake causes toxic products in your brain. When you sleep your brain cells shrink, causing an increased space between them, allowing fluid to wash the toxins out.

It's also an important part of the memory and learning process: it organizes the things you're learning. It rehearses neural patterns of things you're learning, strengthening and deepening them.

If you focus on what you're learning right before you take a nap you have an increased chance of dreaming about it, especially if you want to dream about it. Dreaming about what you're studying can enhance your ability to understand: it consolidates your memories into easier-to-grasp chunks.

Activity

Physical excercise engages the diffuse mode of thinking. This is why it's so important to excercise. I try to make some form of excercise a part of my daily routine as a lifestyle rather than a discipline. For example, I used to commute by bike 5 miles each way to work when I lived in Seattle. This was an excellent way to start the morning, and end the work day. Now that I work from home, I mountain bike over lunch during the summer, and walk, run or go to the climbing gym during the winter. Many times as I've thought about a problem while in the zen state of singletrack mountain biking, the diffuse mode of thinking has brought a very different perspective and creativity to problem solving.

Environment

It's important to work in a space that inspires you to create. If you work from home, carve out a dedicated space to work, and spend time desigining or remodeling if necessary to make it suit your needs. For me, this means a modern space with interesting art and a mix of home made physical computing hackery.

It also helps if you're working near other people are creating and hacking. If you work from home, try to make time to work from coffee shops, find a coworking space to occassionally work from, or even meet up with a friend who freelances to work together.

Chunking

A chunk is a network of neurons working together, built from practice and repetition. New concepts often don't make sense in relation to other concepts as part of the bigger picture. It's important to connect new material to existing knowledge. Chunks are pieces of information that are bound together. One of the first steps to learning is creating chunks which are connected to knowledge through meaning. Once you chunk an idea you don't need to remember all the underlying details.

How to form a chunk

Consider learning a new song on the guitar. The entire song could be considered one large chunk, but can also be broken down into mini-chunks that are easier to learn through repetition. You can then join the mini-chunks together into larger chunks. The joining process can be continually repeated to build up larger and larger chunks. The point of joining small chunks into a larger one is so that you don't even need to consciously think about connecting the individual neural networks.

Learning a language is another example. At first you learn pronounciation and how to string together words to form simple sentences. As you progress, you can more creatively string together complex phrases to communicate subtleties.

When learning a mental concept, form a chunk by:

  1. Focus your undivided attention on the subject
  2. Understand the basic idea you're trying to chunk: let focus and diffuse mode alternate in order to synthesize the gist. There are two approaches that work together. The bottom up approach involves chunking and repetition while top down involves understanding the big picture. Both perspectives are vital and meet at the context level, which helps you learn how and when a chunk applies to the big picture.
  3. Practice and repetition

It helps to learn major concepts first, then go back in and fill in the details.

Further reading