Our brains have to model the world to navigate it
SUPRISES (OR ERRORS) ARE HOW WE LEARN
Each surprise is an opportunity to update our model of the world to be more effective in the future at meeting our needs.
But not all surprises or errors are accurate or helpful. If the brain learned from all errors indiscriminately, it would be as ineffective as if the brain never learned anything at all.
Example: Your Favorite Restaurant.
Every time you go to your favorite restaurant, you order the same dish — penne a la vodka. Every time, it tastes the same — exactly what you expect and want.
This past Friday, though, you showed up, ordered your penne, and woah! It tastes different. It tastes a bit bitter, not as creamy. Surprise!
If you have no more information, you can make one of two choices:
Learn from the surprise: this restaurant is no longer good, and I should never come back, or
Ignore the surprise: it’s a fluke — maybe the chef is out sick, or they couldn’t get their typical supplies — I’ll come back next Friday and hope my penne is back to normal.
Option 1 immediately updates your model of the restaurant: it’s no longer good; Option 2 changes how confident you are in the restaurant being good, but doesn’t update your model of the restaurant entirely.
The next Friday, you come back again and order your penne. Once again, it’s not the same! Now with your confidence diminished from the prior week, you have to make the same choice — learn or ignore the surprise. This second surprise is a bit harder to ignore. A pattern is starting to form.
You come back for the third week, and while you’re hoping for your favorite dish, you’re almost expecting to be disappointed. But, surprise! The pasta is back to its normal, delicious self! Thank goodness you stuck with it and didn’t update your model of the restaurant too quickly.
Now let’s add one more twist: when you ask the host at the restaurant whether the chef was gone for the past two weeks, they reply with one of the two following responses:
a) Yes, he was out sick, but he’s feeling much better now. Hopefully it didn’t disrupt your experience too much.
b) Yes, he’s opened a second restaurant and hired a second chef — he’s planning to split his time between the restaurants from now on.
In scenario a, you’re pretty confident things are back to normal, and your penne is safe. Scenario b, however, changes everything. Now each time you come to the restaurant, it will be a dice roll of whether you get good or bad penne.
Learning
The example above illustrates how neuroscientists think about the process of learning.
For every error, our brains go through an evaluation process to decide whether to update the prior model in light of new evidence, or to ignore this evidence entirely.
We can think about this process as a series of questions our brains ask about the new evidence at hand:
Attention: Does it matter? Could an error in this model impact my ability to meet my needs?
Confidence: Do I trust this new evidence?
Explanation: What could cause my old model to be wrong or reality to change in this way? Does this explanation make sense with how I generally understand the world?
If the answer is — yes, it makes sense that my old model was wrong: either because I wasn’t confident in my old model, or things change, then the brain has to ask
Assessment: can I still meet my needs in light of this new reality?
Action: What am I going to do about it?
Every surprise or error in our model of the world goes through this same evaluation. Whether we learn or not from an error depends on the results of that evaluation process
