| | Brain, Mind, and Intentionality | From my monist’s perspective, the brain and the mind are inseparable events. Moreover, the mind, or mindness state, is but one of several global functional states generated by the brain. Mind or the mindness state, is that class of all functional brain states in which sensorimotor images, including self-awareness, are generated. When using the term sensorimotor image, I mean something more than visual imagery. I refer to the conjunction or binding of all relevant sensory input to produce a discrete functional state that ultimately may result in action. For instance, imagine that you have an itch on your back, at a place that you cannot see but which generates an internal “image” giving you a location within the complex geography of your body as well as an attitude to take: SCRATCH! That is a sensorimotor image. The generation of a sensorimotor image is not a simple input/output response, or a reflex, because it occurs within the context of what the animal is presently doing. For obvious reasons, a dog wouldn’t want to scratch with one leg while another one is up in the air. So, context is as important as content in the generation of sensorimotor images and premotor formulation. There are other states that occupy the same space in the brain mass but which may not support awareness. These include being asleep, being drugged or anesthetized, or having a grand mal epileptic seizure. When one’s brain is in these states, consciousness is lost; all memories and feelings melt into nothingness; yet the brain continues to function, requiring its normal supply of oxygen and nutrients. During these states, the brain does not generate awareness of any kind, not even of one’s own existence (self-awareness). It does not generate our worries, our hopes, or our fears—all is oblivion. By contrast, I consider the global brain state known as dreaming to be a cognitive state, but not with respect to co-existing external reality because it is not directly modulated by one’s senses. Rather, this state draws from the past experiences stored in our brain or from the intrinsic workings of the brain itself. Yet another global brain state would be that known as “lucid dreaming,” where one is actually aware that one is dreaming. In short then, the brain is more than the one and a half liters of inert grayish matter occasionally seen pickled in a jar atop some dusty laboratory shelf. One should think of the brain as a living entity that generates well-defined electrical activity. This activity could be described perhaps as “self-controlled” electrical storms, or what Charles Sherrington, one of the pioneers of neuroscience, refers to as the “enchanted loom.” In the wider context of neuronal networks, this activity is the mind. This mind is co-dimensional with the brain; it occupies all of the brain’s nooks and crannies. But as with an electrical storm, the mind does not represent at any given time all possible storms, only those isomorphic with (re-enacting, a transformed recreation of) the state of the local surrounding world as we observe it when we are awake. When dreaming, as we are released from the tyranny of our sensory input, the system generates intrinsic storms that create “possible” worlds—perhaps—very much as we do when we think. Living brains and their electrical storms are descriptors for different aspects of the same thing, namely neuronal function. These days, one hears metaphors for central nervous system function that are derived from the world of computers, such as “the brain is hardware and the mind, software.” I think this type of language usage is totally misleading. In the working brain, the “hardware” and the “software” are intertwined in the functional units, the neurons themselves. Neurons are both “the early bird” and “the worm,” because mindness coincides with functional brain states. Before returning to our discussion of mindness, think about the itch on your back again, and in particular the moment of the sensorimotor image—before you put into action the motor event of scratching the itch. Can you recognize the sense of future inherent to sensorimotor images, the pulling toward the action to be performed? This is very important, and a very old part of mindness. From the earliest dawning of biological evolution it was this governing, this leading, this pulling by predictive drive, intention, that brought sensorimotor images—indeed, the mind itself—to us in the first place. Let us shore up the discussion with a bit more precision. I propose that this mindness state, which may or may not represent external reality (the latter as with imagining or dreaming), has evolved as a goal-oriented device that implements predictive/intentional interactions between a living organism and its environment. Such transactions, to be successful, require an inherited, prewired instrument that generates an internal image of the external world that can then be compared with sensory-transduced information from the external environment. All of this must be supported in real time. The functional comparison of internally generated sensorimotor images with real-time sensory information from an organism’s immediate environment is known as perception. Underlying the workings of perception is prediction, that is, the useful expectation of events yet to come. Prediction, with its goal-oriented essence, so very different from reflex, is the very core of brain function. | — Rudolfo R. Llinás, I of the Vortex - From Neurons to Self | Indexes/23 |
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