So, what do we do to be able to help a person with anorexia, whose mental noise is so disturbed, yet, they need food? So, let’s explore what’s going on in the inside of the brain, so that we can better understand what that looks like.
As we are looking at this research, we are seeing how the brain fires, through fMRI studies. Now, those are 3D studies, and it’s not just looking at a picture. The “f “means “functional”. So, they would give the patient a task, while they’re watching what goes on in the brain and watching the oxygen blood flow.
So, when you’re eating, and it comes up from the gut and the signals get into the brain, the signal moves through the thalamus right into the insula. And the insula is the part of your brain that gives the indication of hunger or fullness, “I think I’m a little hungry; I better have some breakfast.” “Ah, that toast, that tasted good.” The taste and the degree of hunger comes out of the insula.
Right next to the insula is your amygdala, and that’s your alarm system that says, “Anything wrong with the toast? Okay, then I’ll stay calm, I’ll be quiet.” “Anything wrong with…? Nope, I’m just alright.” So, amygdala just stays quiet.
And then it moves to the bottom of the striatum, and you’re going into the pleasure circuit. And the pleasure circuit, that dopamine, goes to a little high angle. “Woo! That was nice; I’ll have another, hmm, yes!” And so, whenever you make a decision and you get pleasure from it, you have a little dopamine spike. “So, shall I put jam on it?” I taste it, “Hmm, that was good, I’ll have some more.” So you get these little pleasure surges in the dopamine. It’s your brains way, gut sensation, that says, “Yeah, yum!”
And so, then, the front of the brain begins to start interpreting it: “Well, if you liked it, and the amygdala is not showing any alarm, let’s move it forward and let’s have some more.” And then the cortex starts weighing “Is this good/bad?” And so, “Oh, it tasted good, I liked the toast. I’m hungry, then I’ll go ahead and eat it”, says the ACC.
And then on we go to the dorsolateral prefrontal cortex, which is where Carly Simon sings about anticipation. Only I’m thinking about anticipation with food, not other areas. So, when we look at anticipation for the next bite, “Oh, I think I could have another one. That’s fine, I’ll have another bite.”
And parietal then takes in, a sense of the brain that looks at, “How am I in relation to those around me?” So, “Oh, I look okay.” So then, you have another bite. “Hmm, that was good” All right, then have some more. I’ll have another bite, I still look okay. Take a third bite. So, as you’re eating your toast with your jam, and you’re looking around, you’re saying, “Isn’t this good? Why can’t she just eat? Why can’t she just enjoy her food? Look, I’ll fix this for you, I know you’ll like it, It’s really good.”
Now, for the person with anorexia. Same brain, same stations. So, we’ve got the insula, but, when that person takes the bite of the toast, with anorexia, we actually get no signal. None. It’s so flat, there’s no signal for hunger in the insula. There’s no system or signal for the sense that the hunger is getting a little worse. So, while their body is starving, and it’s sending signals up, the insula is not getting it. It’s just letting that serotonin pass right on by, and the serotonin is not registering.
So, they can look at you and go, “Oh, no, I’m not hungry; you go ahead.”
“How could you not be hungry?”
“I’m not hungry”, and they have no signal. They take a bite of toast to accommodate you, so that they’re not feeling like somebody’s focusing too much on them. So they may eat the toast, and, with that, they may feel the taste. But what we’re finding is the flatness of the taste. So, it tastes like cardboard. That doesn’t taste so good. So now they’re starting to eat, but they’re not hungry. They’ve eaten something and it’s a bit flat. So, amygdala’s getting a little worried and it’s going, “Well, that causes me a little concern. If you’re not even hungry, or you don’t get any taste from it, how do I know if it’s not something of concern?”
So, the amygdala begins to, literally, start to rev up and get more and more fearful, a little more panicky. And so, then, we head to that dopamine area, and will they get any sense of pleasure? No; dopamine is flat as well. So, the whole gut sensation is not registering. I get no flavor, I get no sense of hunger and no pleasure from that bite of toast, even with jam.