BBC Science -- Scientists believe they have worked out exactly how we recognise a face when we see it. Experts have known for some time that there is something special about faces that draws us to look at them, even after the first few hours of birth. A brain region called the fusiform face area (FFA) has been pinpointed as key. Now a team at Massachusetts Institute of Technology say in the journal Neuron that they have figured out how the FFA processes this visual information. To find out what was going on in the brain, the researchers asked volunteers to take part in an experiment. The volunteers were asked to look at pictures of different faces and also pictures of an inanimate object - a house. At the same time, the volunteers' brains were scanned using functional magnetic resonance imaging (fMRI), which shows up which areas of the brain are active at any given time. Some of the faces that the volunteers looked at were completely normal, while others had features that were spaced differently or had features that were replaced by those of different faces, such as a different nose or mouth. Similarly, the pictures of the houses were manipulated in the same way - differently spaced windows or different doors. From these experiments, Galit Yovel and Nancy Kanwisher were able to confirm that it was the FFA that processed the visual information. The FFA was not activated when the volunteers looked at the pictures of houses, suggesting that it is indeed specific for faces. They also worked out that it was the face as a whole that was recognised, rather than the individual features or the relative spacing of these features. (12/06/04)
