Ivory Towers: She recognised me from my picture

CAN A chimpanzee tell the difference between men and women? Identifying the gender of someone in a photograph is one of those things that human beings do rather well and computers can barely manage. On a much simpler level, distinguishing between the handwritten letters 'a', 'd' and 'o' is usually easy for people, but a bugbear for any programmer hoping to get computers to read the average human scribble.

Both these skills are the sort of fuzzy-pattern recognition our brains are good at, but which has proved hard to simulate with a computer's brutal logic.

Several years ago, Cambridge pigeons were taught to pick out the letter 'a' and now a New Jersey chimpanzee has learnt to tell men from women. This is reported by Itakura Shoji in a paper, Sex discrimination of photographs of humans by a chimpanzee (Perceptual and Motor Skills vol 74, 1992): 'Photographs of clothed humans were shown to a female chimpanzee which had received extensive training in the use of visual symbols.'

After only four sessions, the chimpanzee had learned to discriminate almost perfectly between male and female. But the matter did not stop there, for another paper appeared shortly after by the same author. In A chimpanzee with the ability to learn the use of personal pronouns (Psychological Record vol 42, 1992), Dr Shoji reports on a female chimpanzee who was trained to match the correct names and personal pronouns to photographs of people. 'The data may facilitate an understanding of other aspects of primates' self-consciousness,' he explains.

Other researchers have moved beyond the planet of the apes. According to an early report from the First Appalachian Conference on Behavioral Neurodynamics, Walter Freeman has extended his earlier work on chaotic processing dynamics in the olfactory bulb of rabbits. His latest investigations concern intentionality in hedgehogs. He concludes that they do use semantic concepts, but their spatial processing patterns are dependent on sensory input.

This follows experiments showing that they stop moving if you block up their nostrils.