[MUSIC]. >> So let's look at emotional movements. And emotional movements are expressed through both the posture and facial expressions. But let's start with facial expressions. And the point I wanna make with this series of slides is this is of a patient who has a stroke in the corticospinal tract, the corticobulbar tract, excuse me. So, with a lesion in the corticobulbar tract on this side, she is unable to move this part of her face. And so the physician has said, please make a smile. Smile in response to a command. And what you see is that on this side her mouth goes up, on this side it does not. So she's able to move this side because this cortex is intact. It crosses, but this cortex is somehow lesioned, and so she doesn't get the message to that side of the face. Now look what happens when the physician instead of saying smile, tells a funny joke. So isn't that remarkable? Now you see that she is perfectly capable of moving both sides of the face. She's been capable of moving the side of the mouth that she moved before. But she is also capable of moving this side of the face. Now the physician is telling her to do too many things, and she is slightly annoyed. And you see that once again. She's able to move both sides of her face to express her annoyance. And finally, let's look at her as she is at rest. At rest, it looks like her face is pretty symmetrical. It's not like this side of her mouth is drooping. And most notably you see this fold on both sides of the face, that's called the nasolabial fold. And that is a product of the corticobulbar tract innervation of facial muscles. The point here is that even with a lesion in the motor cortex, she is able to access emotional movements. And she does that not through the corticospinal tract, but through what are called extrapyramidal pathways. So the corticospinal tract/corticobulbar tract, travels through the pyramids, these are pyramidal pathways and the emotional movements travel elsewhere. And this is an approximation. The reality is that we don't understand as much as we would like to about how these extrapyramidal pathways are organized. But what we do understand is that they are separate from these volitional, intentional, deliberate pathways. And therefore, an individual who has an inability to produce volitional movements in response to a command has complete ability to do the same movement for some other emotional reason. When we have a facial expression, the facial expression that we have at rest, as you look at this facial expression, you see that it's intact. And we know that she has a problem in her corticobulbar tract, in her motor cortex that controls the volitional control of her face. And so what that, in fact, tells us is that the appearance of our face at rest is an emotional act. We produce, the face that we put on is a reflection of our internal emotional state. And we can see that, this is what is used in all sorts of art. So, here is Burghers of Calais. This is one of the Burgher. He's about to sacrifice himself for the good of the town. He's face says a lot. He's face shows sadness and resignation, dignity, and it tells you a lot. And there's nothing semantic that you could say that would dissuade you from the fact that this individual is both sad and dignified. And it's not just us that use our faces to express our emotions. Other animals, other mammals besides humans do this too. Here's Gris-Gris and we call this picture bliss. So she's expressing some degree of bliss. So when we think about how emotional expressions are produced, it's in fact one of the things that actors use all the time. They are able to subtly express an emotional state with their face. And they use this to perhaps, on occasion, express sarcasm. So if the words that a person utters don't match the expression that a person has on their face, that disconnect can be interpreted as sarcasm or as some kind of subterfuge. So another example of this is not just with our face but with our body posture. We certainly tell a lot in how we stand. We have a very different emotional state when we're standing upright with our shoulders back than when we stand like this. If I stand like this and I tell you I'm really happy, you're not gonna believe me. Because it's a clear state of my emotional state. So another way that we can use this is, in fact, if you're not sure how you're feeling, check your face. It tells you how you're feeling. We embody our emotion, and we embody it both in our facial expressions and in our postures. [MUSIC]
