Areas of the body with magnified representation in the somatosensory cortex include the lips, face, fingertips, feet, and genitals due to higher sensory receptor density.

“That representation is scaled in a way that matches sensitivity, so the areas of your body that are most sensitive have a lot more brain real estate devoted to them.”

“They include the lips, the face, the feet, and the genitals and nearby areas, literally nearby areas. Under conditions of higher arousal two things happen, the ability to achieve or experience pleasure at those locations goes up and our tolerance and our threshold for pain also goes up.”

“Well, the lips, the face, the tips of the fingers, the feet, and the genitals. And so this map of you has very large lips, face, tips of fingers, bottoms of feet, and genitals. And that's because the innervation, the number of wires that go into those regions of your body far exceeds the number of wires for sensation of touch that go to other areas of your body.”

“And in your somatosensory cortex, you have a map of your entire body surface. That map is called a homunculus. And if we were to take your cortex and lay it out on a table, I've actually done this with the cortices of various animals and humans included. What you would find is that there's literally a map of your entire body surface. But it wouldn't look exactly like you, this map would be very distorted.”

“When we are in heightened states of arousal, we can achieve pain, we can experience pain and we can experience pleasure. And under those heightened states of arousal, we are more sensitive. Literally the passage of electrical signals from those locations on the body that have heightened degrees or higher degrees, I should say of receptors, use your imagination. They include the lips, the face, the feet, and the genitals and nearby areas, literally nearby areas. Under conditions of higher arousal two things happen, the ability to achieve or experience pleasure at those locations goes up”

“So the areas of your skin that have the highest density of the sensory receptors are magnified in your brain. So it's sort of like having more pixels in a certain part of a camera than others, and in doing that allowing higher resolution in this case of touch, not a vision, but of touch sensation in certain parts of your body.”

“what are the areas that are magnified? Well, the lips, the face, the tips of the fingers, the feet, and the genitals. And that's because the innervation, the number of wires that go into those regions of your body, far exceeds the number of wires for sensation of touch that go to other areas of your body.”

“It's highly organized in a very particular way, which is that the areas of your skin that have the highest density of these sensory receptors are magnified in your brain.... what are the areas that are magnified? Well, the lips, the face, the tips of the fingers, the feet, and the genitals.”

“And in your somatosensory cortex, you have a map of your entire body surface. That map is called a homunculus. It's your representation of touch, including pleasure and pain. But it's not randomly organized. It's highly organized in a very particular way, which is that the areas of your skin that have the highest density of these sensory receptors are magnified in your brain.”