Self Comes to Mind

bewilderment. 5 Since 2000, however, we have known that activity in the insula is indeed an important correlate for every conceivable kind of feeling, from those that are associated with emotions to those that correspond to any shade of pleasure or pain, induced by a wide range of stimuli: hearing music one likes or hates; viewing pictures one loves, including erotic material, or pictures that cause disgust; drinking wine; having sex; being high on drugs; being low on drugs and experiencing withdrawal; and so forth. 6 The idea that the insular cortex is an important substrate of feelings is certainly correct.
    But when it comes to the correlates of feelings, the insula is by no means the whole story. The anterior cingulate cortex tends to become active in parallel with the insula when we experience feelings. The insula and anterior cingulate are closely interlocked regions, the two being joined by mutual connections. The insula has dual sensory and motor functions, albeit biased toward the sensory side of the process, while the anterior cingulate operates as a motor structure. 7
    Most important, of course, is the fact that (as mentioned in the two previous chapters) several subcortical regions play a role in the construction of feeling states. At first glance, regions such as the nucleus tractus solitarius and the parabrachial nucleus have been seen as way stations for signals from the body’s interior, as they convey them to a dedicated sector of the thalamus, which in turn signals to the insular cortex. But as indicated earlier, feelings likely begin to arise from activity in those nuclei, given their special status—they are the first recipients of information from the viscera and internal milieu with the ability to integrate signals from the entire range of the body’s interior; in the upward progression from spinal cord to encephalon, these structures are the first capable of integrating and modulating signals about a comprehensive internal landscape—chest and abdomen, with their viscera—as well as visceral aspects of limbs and head.
    To say that feelings arise subcortically is plausible given the evidence reviewed earlier: complete damage to the insular cortices in the presence of intact brain-stem structures is compatible with a wide range of feeling states; hydranencephalic children who lack insular and other somatosensory cortices but have intact brain-stem structures exhibit behaviors suggestive of feeling states.
    No less important in the generation of feelings is a physiological arrangement that is central to my framework for mind and self: the fact that the brain regions involved in generating body maps and thus supporting feelings are part of a resonant loop with the very source of the signals they map. The upper brain-stem machinery in charge of body mapping interacts directly with the source of the maps it makes, in a tightly bound, near fusion of body and brain. Feelings of emotion emerge from a physiological system without parallel in the organism.
    Let me conclude this section by recalling yet another important component of feeling states: all the thoughts prompted by the ongoing emotion. Some of those thoughts, as I noted earlier, are components of the emotion program, evoked as the emotion unfolds so that the cognitive context is in keeping with the emotion. Other thoughts, however, rather than being stereotypical components of the emotion program, are late cognitive reactions to the emotion under way. The images evoked by these reactions end up being a part of the feeling percept along with the representation of the object that caused the emotion in the first place, the cognitive component of the emotion program, and the perceptual readout of the body state.
How Do We Feel an Emotion?
     
    In essence there are three ways of generating a feeling of emotion. The first and most obvious consists of having an emotion modify the body. Any emotion does this dutifully and swiftly because emotion is a program of action, and the result of the action is a change of body state.
    Now, the brain is continuously generating a substrate for feelings because signals from the ongoing body state are continuously being reported, made use of, and transformed at the appropriate mapping sites. As an emotion unfolds, a specific set of changes occurs, and the feeling of emotion maps are the result of registering a variation superposed on the ongoing maps generated in the brain stem and in the insula. The maps