The
brain is molecules all the way down.
In what is now probably the most profitable
science fiction story of all time (
Avatar), the protagonist transfers his mind to a new body.
Mind transfer has become a staple plot element in science fiction: human to chimp, human to robot, robot to human, alien to human, human to alien-human hybrid...have mind, will transfer.
From time to time it is fun to take stock of the relationship between our science fiction plot devices and real science. The
Dick Tracy science fiction wrist phone of the early 1940s is no longer a gee-wiz science fiction plot element. How are things looking on the mind transfer front?
Luc Reid recently tried his hand at comparing the reality of brain science to science fiction depictions of mind transfer.
While trying to explain the complexity of biological brains, Reid describes the mind-generating machinery of our brains as being composed of "two major systems". Reid's approach to explaining how a brain makes a mind is rather contorted and it made me think of
Paul Churchland's book "The Engine of Reason, The Seat of the Soul". In that book, Churchland was doing some rear-guard maneuvering to convince philosophical
mind/brain dualists that we need not imagine any non-physical components of mind. As an example of how some "explanations" of phenomena can be
too complex, Churchland pointed to Betty Crocker's account of how microwave cooking works.
According to Betty Crocker, microwaves cause 1) water molecules in food to vibrate which causes 2) friction which makes food hot. Similarly, Reid's two step account of brain function involves both 1) neural networks and 2) chemical systems. Betty Crocker imagined that making hot food involves something more than vibrating molecules and Reid imagines that our minds are more than neural networks. What more? According to Betty Crocker vibrating molecules is not enough to make hot food because, in addition, you need heat. According to Reid neural networks are not enough to make a mind because, in addition, you need chemicals. Reid seems to imagine that neural networks are little electrical circuits: "our mind is much larger than our brain, encompassing a wide variety of sensations and emotions that, while they trigger neural activity, are at least as chemical as they are electrical." Similarly, Betty Crocker went out of her way to "explain" to us that microwave cooking is more than just making more molecular motion in our food.
The alternative view of the mind is that, "our mind is the activity of our brain". Just as heat in food
is molecular motion, neural networks in our brains
are chemicals. Sensations and emotions do not trigger neural activity, they
are the activity of our neural networks. There is a famous joke in cosmology about it being "
Turtles all the way down" and in the case of neural networks in our brains, it is molecules all the way down. Neuroscientists do not study neural networks on Mondays and then take up the task of studying
brain chemicals on Tuesdays. The study of neural networks in the brain is fully integrated with and dependent upon the study of brain chemistry. Our neural networks
are chemical systems.
In
The Start of Eternity, the protagonist,
Gohrlay, gets to learn about the advanced brain science that makes mind transfer possible. At no point does she pause and exclaim, "Wait, what about the chemicals?" The story assumes that hard-working scientists have developed the technology needed to scan the structure of a human brain and translate the neural networks into the form of functionally equivalent positronic brain circuits inside a robot. Rest assured, all of the brain chemistry has been taken into account.
Update:
Foundation of Eternity
