Self Comes to Mind

signals at the level of the parabrachial nucleus, directly and indirectly. Exactly what is added in the process is not known, in neural terms, although the addition is likely to contribute to the experiential quality of feelings. Second, the regions that receive body-to-brain signaling respond, in turn, by altering the ongoing state of the body. I envision these responses as initiating a tight two-way, resonant loop between body states and brain states. The brain mapping of the body state and the actual body state are never far apart. Their border is blurred. They become virtually fused. The sense that events are occurring in the flesh would arise from this arrangement. A wound that is mapped in the brain stem (within the parabrachial nucleus), and that is perceived as pain, unleashes multiple responses back to the body. The responses are initiated by the parabrachial nucleus and executed in the nearby periaqueductal gray nuclei. They cause an emotional reaction and a change in the processing of subsequent pain signals, which immediately alter the body state and, in turn, alter the next map that the brain will make of the body. Moreover, the responses originating from body-sensing regions are likely to alter the operation of other perceptual systems, thus modulating not just the ongoing perception of the body but also that of the context in which body signaling is occurring. In the example of the wound, in parallel with a changed body, the ongoing cognitive processing will be altered as well. There is no way you will continue to enjoy whatever activity you were engaged in, as long as you experience the pain from the wound. This alteration of cognition is probably achieved by the release of molecules from brain stem and basal forebrain neuromodulator nuclei. Overall, these processes would lead to the assembly of qualitatively distinct maps, a contribution to the substrate of experiences of pain and pleasure.
Primordial Feelings
     
    The issue of how perceptual maps of our body states become bodily feelings—how perceptual maps are felt and experienced— is not only central to the understanding of the conscious mind, it is integral to that understanding. One cannot fully explain subjectivity without knowing about the origin of feelings and acknowledging the existence of primordial feelings , spontaneous reflections of the state of the living body. In my view, primordial feelings result from nothing but the living body and precede any interaction between the machinery of life regulation and any object. Primordial feelings are based on the operation of upper-brain-stem nuclei, which are part and parcel of the life-regulation machinery. Primordial feelings are the primitives for all other feelings. I will return to this idea in Part III.
Mapping Body States and Simulating Body States
     
    That the body, in most of its aspects, is continuously mapped in the brain and that a variable but considerable amount of the related information does enter the conscious mind is a proven fact. In order for the brain to coordinate physiological states in the body proper, which it can do without our being consciously aware of what is going on, the brain must be informed about the various physiological parameters at different regions of the body. The information must be current and consistent, from time to time, if it is to permit optimal control.
    But this is not the only network that links body and brain. Around 1990 I proposed that in certain circumstances—for example, as an emotion unfolds—the brain rapidly constructs maps of the body comparable to those that would occur in the body had it actually been changed by that emotion. The construction can occur ahead of the emotional changes taking place in the body, or even instead of these changes. In other words, the brain can simulate , within somatosensing regions, certain body states, as if they were occurring; and because our perception of any body state is rooted in the body maps of the somatosensing regions, we perceive the body state as actually occurring even if it is not. 7
    At the time the “as-if body loop” hypothesis was first advanced, the evidence I could muster in its favor was circumstantial. It makes sense for the brain to know about the body state it is about to produce. The advantages of this sort of “advance simulation” are obvious from studies of the phenomenon of efference copy. Efference copy is what allows motor structures that are about to command the