The history of science is discontinuous. It is punctuated with new discoveries and changes of direction. These produce new frameworks which Thomas S Kuhn in his fabulous book, “On the Nature of Scientific Revolutions”, called paradigms.
One of the first was the dramatic Copernican Revolution, when scientists first realised that the earth was not the centre of the Universe but in fact the earth, like the other planets revolved around the sun. This finding was resisted largely on religious grounds because it seemed to significantly diminish the status of the earth and consequently Mankind in the Universe.
Newton’s discoveries in physics enabled the enunciation of many physical laws that helped explain observed phenomena. Newton’s Universe was a mechanical one. It was though God had wound up the Universe clockwork and then stood aside to let it wind down in a predictable fashion.
The focus of scientific endeavour was inordinately focussed on understanding the physical world, how the planets moved, how physical bodies impacted on each other and unearthing the essential physical forces that nature had ordained to order the Universe.
But then of course along came Darwin. In his book, “On the Origin of the Species” he postulated that biological organisms developed over generations by the process of “natural selection”. Again this affronted the sensibilities of the devout because it removed the divine from the creation process. It was a bitter pill to swallow to allow that human beings were not fallen angels but hairless apes!
Then in the early twentieth century Einstein challenged many of the Newtonian concepts of physics. In Einstein’s Universe the essential dimensions of space could not be understood without adding the temporal dimension. Mass impacted on space, mass and energy were interchangeable, mass and time were dependent on velocity, and so on.
Finally Einstein himself was dismayed by another revolution in physics – quantum mechanics. In this new paradigm, at least at the level of the quanta, nothing was certain. Physical reality (whatever that is) was presented as a cloud of possibility until an observer came along. The intervention of the observer collapsed the probability function into a discrete physical outcome. The imprecise nature of our Universe was incorporated in such propositions as Heisenberg’s “Uncertainty Principle.” Heisenberg showed that we could either determine the position of an electron or it momentum – but not both. And so it seems that the closer we look at the Universe the less confident we can be about specific outcomes.
But where now might the next revolution come from? I suspect that the next frontier of science will be neuroscience. We are confronted with the ultimate conflict of dualism – the workings of the human brain and the concept of mind. Understanding how the brain works will no doubt be beneficial to human beings. But I would suspect that it will throw little enlightenment on the human mind.
I was most intrigued a few years ago, to read the transcripts of the 2003 BBC Reith Lectures given by V S Ramachandran. Ramachandran is director of the Centre for Brain and Cognition and professor of psychology and neuroscience at the University of California. He is renowned in his field. Richard Dawkins has called him “the Marco Polo of neuroscience”. (If you need to verify his credentials just “google” him and see his achievements and accolades.) Yet despite (maybe because) of his extensive knowledge of the brain Ramachandran is adamant that the brain does not create “mind”. This is counter to the beliefs of other philosophers with a more deterministic mindset working in this space, like Daniel Dennett or Richard Dawkins himself. I am tempted to postulate that his Indian heritage might have helped him here!
Much of the work of Sigmund Freud has been discredited as we have learnt more about the mind and its processes. However we should be forever grateful for his discovery of the “unconscious”. From this came the idea that even though we claim to be in charge of our destinies, most of our behaviour is governed by a cauldron of emotions and motives of which we are barely conscious.
Ramachandran says (and I am sure that the good Dr Phil would approve) “Your conscious life, in short, is nothing but an elaborate post-hoc rationalization of things you really do for other reasons.”
There are many intriguing disorders of the brain that Ramachandran has thrown light on.
1. Prosopognosia, or Face Blindness. Those suffering this condition can no longer recognize people’s faces. They are not blind or psychotic or mentally disturbed in any way but are simply no longer able to recognize people by sight.
2. Phantom Limbs. Some people when limbs are amputated continue to experience sensations which appear to come from the limb which has been removed.
3. Synesthisia. Many people (one in a hundred or so) experience numbers, musical notes, days of the month and so on as being associated with specific colours.
4. Blindsight. Some people who have brain damage in one brain hemisphere are effectually blind on the other side. However when asked to point to an object they can’t consciously see as a result of this blindness, despite their protestations they can’t possibly do so, almost all can point exactly at the object.
Perhaps just to give you a flavour towards his insights we will look at the latter condition.
Ramachandran points out that it is a common fallacy to believe that the photoreceptors in our retinas are stimulated by incoming light forming a picture on the back of our eyeballs which is then relayed faithfully along a cable called the optic nerve which is then displayed somewhere on a little screen in our brain. This fallacy requires another conscious observer inside the brain (commonly called a homunculus) to receive the image and that observer then needs someone inside him watching that image and so on ad infinitum.
In fact neuro-scientists have identified at least thirty areas of the brain that contribute to our ability to register visual perception. It seems that just as little squiggles of ink, which we call writing, can symbolize or represent something entirely different to their appearance, the patterns of neurons firing in the brain and the action of nerve cells can conspire to create our visual imagery.
It has been known for many years that damage to the visual cortex in one half of the brain leads to blindness on the other side. If for example there is damage to the left visual cortex the person will be blind in the right visual field. However a neuro-scientist working with a patient with such impairment discovered an unusual phenomenon. He introduced a little spot of light to the impaired visual field and asked the patient what he could see. Predictably the patient said, “nothing”. He then asked his patient could he point to the light. The patient was most skeptical about this and remonstrated that he could not possibly point to something he could not see. But at the insistence of the neuro-scientist he did and surprisingly pointed accurately at the dot of light. Over hundreds of trials he pointed accurately at the dot of light with 99% accuracy, even though he continued to claim he could not see it. The patient continued to maintain that he was just guessing whereas the experimental results suggested otherwise.
Without going into the detailed analysis of the brain, Ramachandran showed that there were two principal brain circuits which contributed to our visual perception. The most important one was laid down in modern evolutionary time. It took the signals from the photo-receptors of the retina and built an image that the brain could consciously observe. But there was an older pathway. Prior to the development of the visual pathways enabled by the relatively recent brain development of the cerebral cortex there was a much more primitive pathway that accessed the “old” brain. (For the technically minded it goes to the superior colliculus in the brainstem.) This facility seemed only to monitor position and motion. Whilst the new circuitry resulted in a conscious visual picture, the old pathway provided an unconscious assessment of position and movement.
Those who had impairment of the visual cortex could no longer consciously evoke pictures of the world in their impaired visual cortex field. But surprisingly they could still unconsciously determine position of stimuli through the “old brain” functions.
Some of the pedantic missionaries of metacognition state it is a great concern that we do not know what we do not know. Well I believe it is even of greater concern that we do not know what we unconsciously know!
We are all familiar with a phenomenon similar to Blindsight – “attentional awareness”. As the good Dr Phil has pointed out to me we can be driving the car whilst having an engrossing conversation with someone in the passenger seat. Whilst the conversation is going on we hardly consciously notice our driving effort or the road and the traffic. But if a car comes alongside and puts its indicator on signaling that it is about swerve in front of me and I believe there is not enough room to safely do so, then of a sudden I stop talking, quickly brake and open up the required space. For those few moments my attention is entirely occupied by my driving.
When you reflect on this it is hard to imagine that we could carry on a conversation without our conscious attention (although you might protest you know people exactly like that!) but we seem easily to be able to perform the routine act of driving with little such attention.
I know I have given but a trivial example, but it seems to me that this is where the frontier of science now lies. Understanding the nature of our consciousness and how (or even if) this has been shaped by evolutionary processes seems to me a much more interesting and important field than trying to uncover even more elementary particles! (Perhaps the Higgs Boson might be the last?)