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In I of the Vortex, Rodolfo Llinás, a founding
father of modern brain science, presents an original view of the evolution and
nature of mind. According to Llinás, the "mindness state" evolved
to allow predictive interactions between mobile creatures and their environment.
He illustrates the early evolution of mind through a primitive animal called the
"sea squirt." The mobile larval form has a brainlike ganglion that receives
sensory information about the surrounding environment. As an adult, the sea squirt
attaches itself to a stationary object and then digests most of its own brain.
This suggests that the nervous system evolved to allow active movement in animals.
To move through the environment safely, a creature must anticipate the outcome
of each movement on the basis of incoming sensory data. Thus the capacity to predict
is most likely the ultimate brain function. One could even say that Self is the
centralization of prediction. At the heart of Llinás's
theory is the concept of oscillation. Many neurons possess electrical activity,
manifested as oscillating variations in the minute voltages across the cell membrane.
On the crests of these oscillations occur larger electrical events that are the
basis for neuron-to-neuron communication. Like cicadas chirping in unison, a group
of neurons oscillating in phase can resonate with a distant group of neurons.
This simultaneity of neuronal activity is the neurobiological root of cognition.
Although the internal state that we call the mind is guided by the senses, it
is also generated by the oscillations within the brain. Thus, in a certain sense,
one could say that reality is not all "out there," but that we live
in a kind of virtual reality. Rodolfo R. Llinás
is the Thomas and Susanne Murphy Professor of Neuroscience and Chairman of the
Department of Physiology and Neuroscience at the New York University School of
Medicine. He is the co-editor of the Mind-Brain Continuum (MIT Press,1996.)
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