See the Brain - hgunn.uk

        Although illustrates certain hubs in the brain, and those with higher working memory and intelligence will have more effective connections. These relate to the white matter than connect these hubs.

        They are the motorways of the brain. There are also connections between the different hemispheres of the brain.

The Sesimotor area is where skills like talking, running and cycling are stored in abstract form. We all learn to write automatically. We do not know what we store. It is a procedural memory.

Word formation auditory is where the sounds of langauge are stored.  Semantic memory where word meanings are stored is not stored.

The Conncectome is shown below. There is horizontal gap that can be seen between the two hemisphers of the brain. The red spots indicates the brain hub.

Those have more efficient brains have the equivalent of fast broadband.