One of the topics I have always been fascinated by is the mind-body problem. Specifically, at what point, and exactly how, does our brain become a ‘mind’.
It is fair to say that this aspect of human development is still a deep mystery – while we can see the developmental path for the physical hardware of the brain, we still don’t seem to have a handle on the mind. Naturally, this lack of knowledge is pounced upon by the religiati, eager to point out that what I’m referring to is the soul, and it’s god-given.
But as you would expect, no, I don’t buy that.
In this earlier post dealing with the subject of ‘order out chaos’, I referred to cosmologist Paul Davies who speculates that while arms, legs and all our other bits are basic properties of human development, the mind is actually what he calls an ’emergent property’, and that it emerges as a result of the complexity of the brain. He used as an analogy many other physical systems which, when complex enough, will display some very unexpected behaviour.
As we learn more and more about the way the brain works, some of the mystery is gradually being addressed, and many of the human attributes or behaviours ascribed to the mind (or soul), can now be traced back to the hardware in our heads – in effect making the mind-body a problem simply a question of engineering.
One such example is that of mirror neurons, which have found to be responsible for the behaviour known as empathy. These neurons can be seen to be active when we decide to carry out some task, like open a door. But, they also fire when we see someone else open a door (hence the description of ‘mirror’). What that essentially means is that we are hard-wired to experience things that other individuals are experiencing, which puts us in their shoes, as it were. Mirror hardware is also directly involved in learning and imitation, and there is some speculation that problems in that area result in cognitive disorders such as autism.
For an entertaining discussion of this area, go to this episode of the ABC’s All In The Mind. It features a fascinating discussion between Marco Iacoboni, a neuroscientist researching mirror neurons, and the Dalai Lama – representing the ‘mind’ side of the equation you might say.
A subsequent episode of All In The Mind called Neural Engineering takes a look at the more practical aspects of the mind-body problem – looking at our efforts to control prosthetic limbs simply by thinking about them. It turns out that we are now able to intercept the signals that travel from the brain to the former limbs, and use them to control a prosthetic arm, via a nearby but unrelated muscle – for example, part of the bicep. For example, the subject in this episode has lost his arm from the elbow down. But his nerve pathways have been modified so that thinking about clenching his fist results in a twitch in part of the bicep. The movement is captured by the prosthesis, and used to control it’s grip. In fact, a recent piece of work succeeded in doing this with a chimpanzee. The interesting thing here was how they trained him to generate thoughts which were specific enough to measure and interface to a computer. They actually made use of mirror neurons – by repeating an action in front of the chimp, they could observe the chimp’s mirror neurons firing, to the extent that they could reliably measure and characterise the signal. Once that was done, the researchers knew what the signal was that would result from that action and therefore program a robot or prosthesis to respond to the chimp’s thoughts. Nice one.
While this is admittedly not really very far into the ‘mind’ side of things, it does show that progress is being made, at least to the extent that we can tap into ‘free will’. As we progress down this path, I’m sure a whole range of ethical questions will arise, particularly not to mention objections on religious grounds, but that will just be more fascinating blog-fodder, right?