Part of the Brain: The Inside Story exhibition.
Memories are the refiring of the same neurons that fired when you first had a particular thought or experience. You can actually see changes in the neurons when memories form. Synapses can grow stronger as you learn. But memories are often messy and unreliable. So why, then, do memories exist?
Our memories are essential. They help us learn from past experiences and make smarter decisions in the future. We remember procedures--how to do things without thinking about them, like riding a bike--differently than we do emotionally based memories. This is because your basal ganglia handles procedural memory, while your amygdala burns highly emotional moments such as a first kiss into your long-term memory.
© 2010 Gerald Slota
Memories aren't like photographs: Each time you remember something, it comes out a little different. We forget most things, and usually only remember something when we are reminded of it. That's why we keep souvenirs; a single seashell can bring back memories of an entire beach vacation. Without cues like this to remind us, many things would be forgotten. But there are advantages to forgetting things: Our brains evolved to summon memories that relate to what's happening right now, not to swamp us with random details.
Your short-term memory lets you remember things for around a minute or so--just long enough to think about them. If something is especially noteworthy, or is repeated many times, it might get stored in your long-term memory, allowing you to recall it years later. But most short-term memories are forgotten as soon as you move on to something else.
You can often remember things better if you group them into "chunks." For instance, thinking about a frog, a hat, an umbrella, and a pipe takes a lot of short-term memory if you try to remember each individually. But imagine the frog wearing the hat, holding the umbrella, and smoking the pipe, and you can remember it as one image.