PULSE Magazine | August 2019 Issue PE

"To our knowledge, this is the first report of musical hallucinations of non-recognizable songs that were recognized by others in the patient's environment," the researchers wrote.

The scientists said the woman had likely known the song at some point, but forgot it. The case raises the question of what happens to forgotten memories, they said, and suggests that memories can be stored in some form in the brain that renders them accessible, and yet unrecognizable.

It is possible that the woman had fragmented preservation of musical memories, with key portions of those memories lost. As a result, she couldn't recognize those memories, the researchers said.

Brains may be programmed to forget infancy Our earliest childhood memories fade, and there's likely a reason for that, researchers say. Most often, people don't recall any memories from their earliest years of life, usually before age 3 or 4. This is called infantile amnesia.

Scientists previously thought that early memories were there, but children just didn't have the language skills to verbalize them.

However, recent research shows that children do make memories during their early years, but then forget through deliberate mechanisms. One possible explanation for this is that the developing brain, while growing exponentially and generating cells, wipes out stored memories.

Brain injuries may cause forgetting It is possible to lose memories before they even have a chance to become stored, due to injuries in the brain's structures that are specifically involved in handling memory formation, maintenance and recall. Damage to these areas can result in curious forms of amnesia. In one of the most-studied cases of such amnesia, Patient H.M. lost the ability to form any new memories after a part of his brain, the hippocampus, was removed during a surgery to treat his epilepsy.

Another famous case records the story of Patient E.P., who had a similar fate after he had inflammation of the brain caused by a virus.

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