How is it that people who suffer from amnesia retain the ability to comprehend and speak the language they did prior to the event that caused the amnesia?

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How is it that people who suffer from amnesia retain the ability to comprehend and speak the language they did prior to the event that caused the amnesia?

In: Biology

Amnesia normally refers to a condition in which a person is unable to form new short term memories. Long term memories and skills are more inherant and are stored and therefor function differently, leaving them usually unaffected.

Different brain regions. Regions in your frontal, temporal and parietal lobes formulate what you want to say and the motor cortex allows you to say it. The hippocampus is responsible for some memory, specifically episodic memory. Although the type of amnesia often seen in daytime tv shows is extraordinarily rare.

In addition to the other answers – there are separate brain regions that control speech, and they can be damaged causing different speech impairments. Damaging Broca’s area can result in difficulty speaking at all, lacking full sentence structure, but with meaning intact. Damaging Wernicke’s area, on the other hand, results in fluid and grammatically correct speech, but lacking all meaning, as the words are just nonsensical, like a bad mad lib.

There are different kinds of amnesia. None of them look like how amnesia is typically portrayed in movies and TV.

Quite often speech and language skills are affected, as are basic skills like tying shoes, holding a pen or pencil, doing up buttons and so on.

It all depends on the type of amnesia, which areas of the brain are damaged and how bad the damage is. Sometimes what was lost can be regained, but about half the time whatever is lost is gone for good.

I know a woman who had a pair of mild strokes (TIA) and pretty much lost all of the 70s. It affected her balance for a few years as well. Everything else is intact. (retrograde amnesia)

A man I know has had multiple minor strokes and two severe strokes. He’s lost a fair bit of vocabulary and the ability to tie knots or use a map and compass. He also struggles with forming and accessing short term memories. (retrograde and anterograde amnesia)

As everyone has said, there are different brain regions that are major contributors to certain tasks. The hippocampus is a major player in long term memory storage. There is a well studied case of a patient named Henry Molaison where they removed parts of his hippocampus. He developed amnesia and could not form new memories. One of the things they had him do was trying to see if he could still learn physical skills. He had to draw a star but by looking at the reflection instead so it’s more difficult. They saw that he got better at it with repeated trials even though he has no recollection of doing the task and for him, it’s always the first time he’s doing it. With this, it seems that learning skills with movement(procedural memory) are processed differently. So they concluded that different memories are processed differently. It’s not just one big entity called “memory”. You can lose some memory (by injuring certain brain parts) and still be fully functional on others (uninsured brain parts).