The science of the face
The science of the face
The fascination of the face
For scientists, particularly those who are bio-cyberneticians, the face has a particular fascination, precisely, we are told, because it carries so many different social meanings, each with its own evolutionary and cultural history. This journal has already published papers concerned with identification of facial expressions (see Lee (1994) and other contributors) so that fear and anger can be recognised and even pain so that some fail-safe system can monitor its human operator's state of health or wellbeing. While this type of research has so far only been concerned with some of the basic facial movements an understanding of the underlying science is being pursued. One of the most interesting aspects has to be the way the brain performs all the tasks that are necessary to recognise facial activity. There are specialist areas of the brain, we are told, which have distinct functions in this respect. Another study may well concern itself with one's own response,particularly facially, to another human's facial expression.
Understanding facial expressions.
Dr Andy Young who is Professor of Neuropsychology at the University of York, UK and president of the British Association has written, with Vicki Bruce, the book, In the Eye of the Beholder: The Science of Face Perception (Young and Bruce, 1998). It was no surprise, therefore, to see that the latest insights were presented by neuroscientists and psychologists at a symposium and exhibition of the British Association at their Science Festival at Cardiff, UK in September 1998. In DrYoung's report of the symposium published in the UK's Daily Telegraph(9 September 1998) he writes:
We are all experts when it comes to faces. When we walk along a crowded street we may pass hundreds of people yet the unexpected face of a friend is recognised instantly. When we look at an advert in a magazine we know whether a face is male or female, old or young, even though we may never have seen it before. We can tell from people's facial expressions whether they are tired, apprehensive, angry, sad or happy,and their direction of gaze reveals whether they are interested in what we are saying. These skills have been honed over hundreds of thousands of years of evolution because they are so important. The ability to read a face can start a war, end a love affair or save a life. But how do we doit?
Researchers are asking the question whether the brain has developed regions which are specialised for the task of face perception and whether these areas analyse all the social signals we get from the face or just some of them. The current thinking is that the brain does indeed allocate the task of face perception a number of specialist brain areas that are located on distinct neurological pathways. It would seem that these pathways have been revealed by examination of those people who have had the misfortune to have a stroke or other disease that damages particular parts of the brain. At the Cardiff symposium these were discussed at length.
Parts of the brain identified in different types of recognition
Professor Young provides some information which relates the parts of the brain that have been identified in different types of recognition.They include :
Fusiform gyrus (in occipital and temporal lobes) enables facial recognition of known people.
Insula (in frontal lobe vicinity) enables recognition of expression of disgust.
Amygdala (basal ganglia lies beneath temporal lobes) enables recognition of fear/anger.
We are told that the incredible specialisation of the brain raises a more profound question concerning our conscious experience and sense of self. That is, if our brains depend on diverse regions or neurological pathways with specialised functions, why does'nt the world seem more fragmented to us?
Dr Young sums up his report by saying:
What makes the neuropsychological findings so counter-intuitive is that we get no sense, when we gaze at a face, that our perception is anything but unitary. The effort to reconcile our single consciousness with the diversity of specialist areas in our brains will be potentially fruitful for those of philosophical dispositions.
B.H. RudallNorbert Wiener Institute and University of Wales (UK)
