START ^^
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First: why does this matter? Well, you've got a brain, and one of the most prominent features about it is that it's split in half left↔right. You might know some things about what's on each side, but why do these functions need to be separated? 🤔
Most people have major internal conflicts, and want a better way to deal with them than a tug-of-war. And guess who the two main factions are...
tweet about L↔R conflict
Last "why" piece is personal: for me, learning about this model has been a major tipping point in my capacity to notice when I'm self-deceiving.
So!
It's important to understand the role of attention in cognition. Before your brain can interpret the world, it first needs to summon the world inside of it.
& it's well-established that two hemispheres do this in a very different way—not just in humans but in most species!
TODOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO_pics from p28
Which is convenient, because the overhyped & misleading early brain hemisphere models made brain lateralization unfashionable as a topic (hence my disclaimer above) — but fortunately, only in psychology.
So lots of great work was done with eg birds, & much was learned from that!
In a tiny bird, the left hemisphere (using right eye) is used for pecking at seeds or picking up pieces of material to use for a nest.
The right hemisphere, meanwhile keeps an eye out for predators or other unknowns.
More generally, in most species the left hemisphere is used for categorizing & manipulating known & understood parts of the world.
And the right hemisphere attends to everything else: that which we don't understand, a subtle way in a space has changed since the last time...
The left hemisphere, therefore, has very focused attention: its world is only what it's looking at or thinking about.
Without the RHem to notice things outside of LHem field of view and point it at those things instead, they might as well not exist: "hemispatial neglect"
This is asymmetric! The right hemisphere attends to the whole thing, so it doesn't make these errors without its LH partner. (It does need the LH, but it doesn't seem so absurd without it.)
Other things
master & his emissary story
other stuff from Ways of Attending
stuff about language/grasping/grokking?
stuff about rship between gesture & verbal meaning
confabulation
People with right-hemisphere strokes often confabulate extensively, explaining that their left arm isn't paralyzed, they just... don't want to move it. The same doesn't happen with a left-hemisphere stroke (and not just because such people often can't speak!)