Your Brain: The Missing Manual

Long-Term Memory

Scientists have spent years searching the brain for the biological equivalent of a memory filling cabinet, where past experiences are stowed away. No such storage place has ever been found. Instead, it now seems certain that the brain remembers by "walking through" massively interconnected groups of concepts that are stored throughout the brain.

For example, say you're trying to remember what you ate for breakfast last week. To dig up the right information, your brain might lead you on a quick tour through your morning routine or a catalog of your favorite foods. Along the way, it asks leading questions (Were you in a hurry? Did you eat alone?) and seamlessly fills in the details you can't remember with some educated guesswork. You're unlikely to notice this process taking place, because the brain can stitch these millions of pieces together into a memory that seems remarkably whole and complete.

How Memories Are Stored

As you learned in Chapter 1, it's relatively rare for new neurons to appear in your brain. However, the structure of your brain is being continuously reworked. Synapses—the connections between neurons—are constantly being strengthened or weakened, and new dendrites are growing to link neurons together in new patterns. This continuous process of brain reorganization underlies all long-term memory and learning.

Note

A common misconception is assuming that memories are stored in some sort of container in your brain and that your neurons simply pull ...