When people have amnesia and lose memories of the past, including what their spouses look like or even the fact that they’re married at all, how can they still speak and understand a language?
—Bruce B., Las Vegas, Nev. Amnesia is a rare phenomenon, but it can occur in many forms, depending on what caused it—a stroke, a head injury (even mild concussions may cause memory loss), a tumor, a disease, alcohol or drug abuse, a terrible shock, etc. Certain medications may also cause amnesia. In the great majority of these cases, sufferers forget masses of facts, such as information and experiences, but their self-awareness and personalities remain intact, and they don’t forget skills they learned, including speaking a language, riding a bicycle or playing an instrument.
Many famous cases exist. For example, a British conductor and musician contracted a brain infection at the age of 47 and was left with a memory of only a few seconds (an extreme case of permanent amnesia), but at the age of 73, he could still read music and play the piano. To generalize, we might say that amnesiacs may forget “what” but not “how.”
The term "amnesia" also refers to the loss of ability to form new memories, making it difficult to learn. This is a more common type of amnesia than the inability to retrieve past memories. Send questions to