Making Connections in our Brains
When we make a memory, we create connections in the brain. The neurons in the brain connect to each other. This connection gets stronger and stronger the more they are used. Eggheads call this long-term potentiation…and…I’ve lost you, right? Well try and stick with me, if you can.
One way we can look at this by thinking of these connections as drawing lines on a page.
We first draw a line, and
Then another line and then another.
Each line is a memory. No line is darker or stands out more than the others. However, whenever we access a memory, we trace over its line again. The more we access it, the more times we trace over the line. This line gets darker and darker. Thicker. Stronger. It stands out from the rest.
As these neural pathways or neural networks get used over and over again, they become engraved and messages are more likely to be sent through these paths of least resistance. We can think about this like walking in the bush. Picture yourself walking through the bush. Initially, there are no footprints. As we walk, we leave footprints behind. Eventually, the paths that are used the most become worn into the dirt. They produce thick paths. Well worn paths. When we try to get from A to B, we tend to follow this well worn paths because they are easier to walk along. They provide the least resistance. We don’t have to ‘bush bash’ as much.
Synaptic consolidation is relatively fast and usually happens within minutes or hours. However, it is open to interference. Ever learned something the wrong way at the start and you keep getting it wrong later? I think I probably learned left and right wrong! Another example is doing three-point turns. I remember my instructor telling me to check the area to the front left of the car before trying a three-point turn. But I didn’t remember to do this. During my synaptic consolidation, my memory was subject to interference (I think I forgot to check or was distracted). Now, I still forget to check. I am embarrassed to say how many trees and poles I have ‘gently nudged’ while doing three-point turns. I forget to check the spot to the left, I start my turn, and then reverse into the tree! Luckily, my first car had plastic bumper bars!
The second level of consolidation is called system consolidation. We can think of this is backing up these new memories into long-term storage. In reality, the information is transferred from the part of the brain called the hippocampus to the neocortex. Unlike synaptic consolidation, system consolidation is slower and takes days to years. However, it is more resistant to interference.
So why would we have two ways to store information? Wouldn’t just one do?
Psychologists argue that having two ways solves a problem called ‘catastrophic interference’. So what is ‘catastrophic interference’ you ask? It is where a new memory overwrites or distorts an older memory.
We have all had this, we learn a new thing and it erases an old thing. Sometimes it is good. For example, say you own a Japanese car with the indicator on the right. Then you guy a new European car. Suddenly, you start indicating by wiping your windscreen!
We need to replace the old memory with a new one. However you don’t always want this to happen.
Here is an example.
Say you see an apple for the first time. You learn that it is a fruit and an apple.
Next you see an orange. You learn that this is a fruit and an orange.
If you had one way to remember things, you’d forget that an apple and orange are different and the orange would replace the apple in your mind.
However, if you have a fast and slow system, this solves the problem.
You will remember an orange and an apple but also remember that they are both fruit.