Researchers in the USA are making headway in mapping the flow of information in human brains. (notice the pun?) One particular find is how the direction of info flow flips when a person switches from imagining to perceiving (or reality).
When you are seeing / perceiving the real world the flow is: Eyes -> optic nerve-> Occipital Lobe -> Parietal Lobe
When you are imagining the flow is: Parietal Lobe -> Occipital Lobe
So what do these Lobes do?
The Parietal Lobe is a higher order region, lets call it a device, that combines inputs from various sensory regions. The Occiptal Lobe makes up most of the Visual Cortex.
So let’s see if I have this right:
Visual information normally comes into the Visual Cortex (occiptal lobe) from the Eyes. This is seeing. It then moves to the Parietal lobe. Somewhere in this I suspect is Perceiving – making sense out what was seen.
When we imagine things information comes from the Parietal lobe and goes to the Visual Cortex. So the we’re concocting a thing to ‘see’ with some higher order part of the brain and the information that will result in a visual interpretation (in the visual cortex) of that thing originates further upstream and comes through the Parietal Lobe on its way.
This is the so called ‘minds eye’ as it works I’ll bet.
So this make me wonder about internal speech. Most people when thinking to themselves about something will sound out words internally. A literal internal speech process.
This discovery makes me wonder if they did this test with people listening to speeches or music or sounds and then asked then to remember those same sounds woul they find the same flow reversal between the parietal lobe and the Auditory Cortex?