The feeling tone is a good example of where the Dharma maps well to neuropsychology. In the Dharma, there’s this notion of the chain of Dependent Origination. One part of that chain that contains great opportunities to reduce or eliminate suffering is the sequence of contact > feeling tone > craving > clinging > suffering.
Contact is the meeting of three things: an object, the sense organ that apprehends that particular kind of object, and the consciousness that goes with that particular sense organ. Following contact, the brain produces a feeling tone that is pleasant, unpleasant, or neutral to help you know what to do: approach the pleasant, avoid the unpleasant, and move on from the neutral.
This mechanism is a very effective way to promote survival in the wild and the passing on of genes. Feeling tones are important in evolution and they are a central theme in the Dharma: for example, they are one of the Five Aggregates, and also one of the Four Foundations of Mindfulness.
Say the phone rings. Depending on whether you’re waiting for a call from a dear friend, or doing something really important and don’t want interruptions, you’ll get a different feeling tone: pleasant, unpleasant or neutral.
In the brain, the amygdala and hippocampus register pleasant/unpleasant and then broadcast a signal widely.
In Dependent Origination, what follows feeling tone is craving. We crave the pleasant, and the ending of the unpleasant. Either way, it’s a kind of craving. After craving comes clinging, a sort of a more congealed, substantiated, enacted, “you’re in it” form of craving. And then, what follows clinging? Suffering.
Equanimity can break the chain right between feeling tone and craving, like a big, jumbo scissors. You let the feeling tone be. It gets into the “mud room” of your mind—that outer room where the muddy boots and wet jackets get left— but it doesn’t enter the central “living room” of your mind. Equanimity increasingly allows us to just be present with the pleasant, the unpleasant and the neutral, alike, without getting reactivated around them.