86 P H V SIC S OF THE IMPOSSIBLE
MAPPING THE BRAIN
Some scientists have advocated a "neuron-mapping project," similar to
the Human Genome Project, which mapped out all the genes in the human genome. A neuron-mapping project would locate every single
neuron in the human brain and create a 3-D map showing all their
connections. It would be a truly monumental project, since there are
over 100 billion neurons in the brain, and each neuron is connected
to thousands of other neurons. Assuming that such a project is accomplished, one could conceivably map out how certain thoughts
stimulate certain neural pathways. Combined with the dictionary of
thoughts obtained using MRI scans and EEG waves, one might conceivably be able to decipher the neural structure of certain thoughts,
in such a way that one might be able to determine which specific
words or mental images correspond to specific neurons being activated. Thus one would achieve a one-to-one correspondence between
a specific thought, its MRI expression, and the specific neurons that
fire to create that thought in the brain.
One small step in this direction was the announcement in 2006 by
the Allen Institute for Brain Science (created by Microsoft cofounder
Paul Allen) that they have been able to create a 3-D map of gene expression within the mouse brain, detailing the expression of 21,000 genes at
the cellular level. They hope to follow this with a similar atlas for the
human brain. "The completion of the Allen Brain Atlas represents a
huge leap forward in one of the great frontiers of medical science-the
brain," states Marc Tessier-Lavigne, chairman of the institute. This atlas will be indispensable for anyone wishing to analyze the neural connections within the human brain, although the Brain Atlas falls
considerably short of a true neuron-mapping project.
In summary, natural telepathy, the kind often featured in science fiction and fantasy, is impossible today. MRI scans and EEG waves can
be used to read only our simplest thoughts, because thoughts are
spread out over the entire brain in complex ways. But how might this
MAPPING THE BRAIN
Some scientists have advocated a "neuron-mapping project," similar to
the Human Genome Project, which mapped out all the genes in the human genome. A neuron-mapping project would locate every single
neuron in the human brain and create a 3-D map showing all their
connections. It would be a truly monumental project, since there are
over 100 billion neurons in the brain, and each neuron is connected
to thousands of other neurons. Assuming that such a project is accomplished, one could conceivably map out how certain thoughts
stimulate certain neural pathways. Combined with the dictionary of
thoughts obtained using MRI scans and EEG waves, one might conceivably be able to decipher the neural structure of certain thoughts,
in such a way that one might be able to determine which specific
words or mental images correspond to specific neurons being activated. Thus one would achieve a one-to-one correspondence between
a specific thought, its MRI expression, and the specific neurons that
fire to create that thought in the brain.
One small step in this direction was the announcement in 2006 by
the Allen Institute for Brain Science (created by Microsoft cofounder
Paul Allen) that they have been able to create a 3-D map of gene expression within the mouse brain, detailing the expression of 21,000 genes at
the cellular level. They hope to follow this with a similar atlas for the
human brain. "The completion of the Allen Brain Atlas represents a
huge leap forward in one of the great frontiers of medical science-the
brain," states Marc Tessier-Lavigne, chairman of the institute. This atlas will be indispensable for anyone wishing to analyze the neural connections within the human brain, although the Brain Atlas falls
considerably short of a true neuron-mapping project.
In summary, natural telepathy, the kind often featured in science fiction and fantasy, is impossible today. MRI scans and EEG waves can
be used to read only our simplest thoughts, because thoughts are
spread out over the entire brain in complex ways. But how might this