Why do we have two brain areas responsible for speech?

[Eagle9]

Broca's area is responsible for speech, right? It is well-known from the 19-th century.

However, from the other hand human’s brain has the second area responsible for the same function - motor cortex:

So please, tell me: why do we need two areas responsible for the same function? Do they collaborate? Or what?

 

[jim mcnamara]

Brain structures evolved over very long periods of time. You cannot always map a particular function to a single brain structure, often many parts of the brain work in tandem. Thinking of the brain as a computer with attached devices is sometimes useful, but in this case it gets you to confusion.

For a simple example: why would certain smells evoke very strong old memories for you? Answer: because olfaction (smell) is very old trait, and other functions in the brain evolved later on to be in the 'path' of interpreting smells and some functional areas branch off into special memory areas.

I like cartoons that get you to think - so what does this say about some older computer application (MS-DOS) that worked well? Can we still use it? Should we change it out only because it is old? (apply this to smell. Or speech -- which evolution added on top of existing functions and connections in the brain)

https://xkcd.com/1891/

 

[.Scott]

The primary motor cortex allows you to move your lips, tongue, etc.
Broca's area allows you to express language verbally.

 

[Pythagorean]

The muscle execution of these speech patterns is the output - there's a lot of processing that happens before its turned into muscle movements.

Broca's area is currently thought to somehow process and integrate information about the way words are formed and how they work together - it negotiates with both the the frontal cortex and the temporal cortex that are associated with "phonemic sequences" - which are, to oversimplify, series of vocalized syllables.

 

[Eagle9]

jim mcnamara

.Scott

Pythagorean

Thanks, it is clear – more or less