How Do You Feel? An Interoceptive Moment with Your Neurobiological Self

"Bud Craig is a functional neuroanatomist, so for his whole career he has worked on body processes, on the signals that come from the periphery of the body—from interoception, from gut feeling, from the heart, from the lungs—into the brain. And as he shows, in humans and apes, into the insular cortex. The insular cortex is the primary interoceptive cortex, meaning it is the primary area in the brain that catches signals from the body and integrates them into motor processes. So as you feel yourself sitting on your chair, that is all insular cortex processing. “So as you feel yourself sitting on your chair, that is all insular cortex processing” This is related to my research because I showed with functional images that brain activity during time perception is strongly correlated to insular cortex activation. This is what I wrote in my book: that we perceive time as being in the outside world, but the subjective component of time is not in the outside world—you could say it is felt by ourselves, our bodily feelings. So I relate my work to Bud Craig’s to interpret my insular cortex findings related to time perception, because this gives the interpretation that our bodily feelings are the basis for subjective time. You could say it is related to the feeling of the passage of time. So it is not so much related to millisecond timing of tapping or in-language processing where we have to be able to discriminate everything in short milliseconds of duration. But to feel conscious of time, to feel the passage of time, there are also other neuroimaging studies which show how important the insular cortex is in this respect. The insular cortex is on the upper layer of the brain, the cortices layer. If you opened a skull and looked into the brain, you would see the cortex but not the insular cortex. You would have to dig on both sides, left and right, into the fissures, and it is hidden a little below. If you opened the fissures you would see it pop up, like an island. I have only seen it through functional imaging. I’ve seen it getting active, but only functionally, through the imaging system."