LEARNING ABOUT MEMORY FROM INJURED BRAINS

The brain is the control centre for all of our activities. Brain injuries interfere with the brain’s normal processes. Injuries damage nerve cells, and then brains cannot send information in an effective way. Scientists have learnt a lot by studying brain injuries, especially about memory.

During the First World War, many soldiers suffered brain injuries. By studying injured brains, scientists saw that injuries in the same regions usually caused the same symptoms. They used this information to create maps of brain regions and their functions. Much of what we know about the brain today stems from these studies on brain injuries.

A healthy brain works like a computer. It takes in, stores and later retrieves information. New information is first stored in our short-term memory. The important information is then moved to another area and stored in the long-term memory. The more this information is accessed, the more likely it will stay in the long-term memory. These bits of information last for years.

An injured brain can have trouble with both long-term and short-term memories. Injured people are unable to recall the past and sometimes can’t even remember their own names. Problems with short-term memory are much more common, however, and since short-term memories are the building blocks for long-term ones, both are affected. Once a person suffers a head injury that affects short-term memory, he or she will have difficulty creating new long-term memories. The effects are amazing. The person whose brain has recently been injured can talk about memories from 15 years ago but often not about things that happened 15 minutes ago.

To review, memory is complex, and it is often affected by head trauma. Short-term and long-term memory can both be affected, and sometimes the damage can be permanent. Fortunately, many head injuries heal over time. As scientists learn more, they will become better able to contribute to the healing process.