Acknowledgement grocery resources notes
HOW WE SEE
You would think that we see with our eyes.
The truth is that light into our eyes, hits the rods and cones of the back of the comes eyes (the retinae), and is transformed into electrical impulses that travel to the visual cortex in the rear section of our brain.
The cortex is the largest part of the brain responsible for higher-level functioning, like thinking, memory, vision, and feelings. The visual cortex, a small part of the whole cortex, creates the images we see.
In fact, a significant proportion of the nerve fibers that connect to our visual cortices come not from our eyes, but from within the brain.
We need to have instant access to memories of what things look like in order to rapidly process incoming images.
What we see is very de- pendent not only on what is present before us, but also on our memory of those things and our thoughts and feelings about them.
BABIES' BRAINS
We are all born with brains that come with some neural circuits already installed. For instance, babies can recognize their mother's face from the approximate distance at which they are usually held.
They can smell their mother's milk, suck, and swallow.
They cry when they're unhappy for reasons that are obvious-they're tired or hungry-and sometimes for reasons that are not so obvious.
At first, everything they do is because of the neural circuits they're born with.
As they grow, they establish new neural circuits virtually every day, eventually learning how to roll over, sit up, babble, walk, and then talk.
BRAIN OVER BODY
There are many feedback loops between our brains and our bodies.
If our blood sugar becomes low, the brain detects that and activates the release of hormones such as adrenaline, glucagon, and cortisol to raise it.
After eating a meal, our brain will send signals to release insulin to lower the blood-sugar levels. Interestingly, our brain will also act to predict what it needs to do based upon prior experiences.
Ghrelin is a hormone released by specialized cells in the stomach when our stomachs are empty, when we have not eaten for a while, or when the blood-sugar level is low.
This hormone signals our brains to create hunger. After we've eaten, these cells turn off ghrelin production and the hormone levels decline.