
4. How are memories stored and retrieved?
Memories make each of us unique and give us continuity in life. Further insight into how memories are stored and retrieved came from a 1953 study on an epileptic patient known as patient Henry Molaison. In an attempt to treat his severe epileptic seizures, neurosurgeons removed his medial temporal lobe, a section of the brain that includes the hippocampus. The surgery worked and the seizures ceased, but it also rendered Molaison unable to make memories of new events.
This finding revealed that the hippocampus is crucial for making new memories. Scientists now believe that the hippocampus makes new memories via long term, sustained signal transmission between neurons, a phenomenon known as long term potentiation.