On your wavelength

Most people's interaction with their computer is pretty one-way. It crashes; they shout. The computer remains stoically unmoved by irritation, anger or out-and-out rage, even if it actually gets thumped pretty hard. But that could be set to change.

Researchers are working on the computer of the future: one that will recognise how its human operator is feeling, and react appropriately. Rosalind Picard is associate professor of media, arts and sciences at Media Lab, part of the Massachusetts Institute of Technology, and the team she works with are pioneers in the field of "affective" computing.

Prof Picard - whose array of space age gadgets rival her namesake's, Captain Jean-Luc on Star Trek - is working on computers that can recognise their operators' voice patterns, facial expressions and other physical manifestations of anger, frustration or happiness. "If the computer can see if what it has done annoys you or makes you happy, it can change what it does," she explains. "For example, if there was a particular feature that always popped up on your screen and your reaction was `Grrr, this feature is driving me crazy', the computer could then either offer to turn it off for you or show you how to turn it off yourself."

This self-customising would save a lot of aggravation for the user. But the difficulty is that the subtlety and range of human expression are not easy for a mere machine to decipher. Remember the bit in Star Wars where Luke, Leia, Han and Chewie are stuck in the Death Star's garbage compactor, which is slowly crushing them? C3PO is frantically trying to de-activate the mechanism, all the while hearing a cacophony of yells from inside the compactor. The despairing droid curses his slowness, thinking his friends are being squished to death, when in fact they are shouting with joy. This, says Professor Picard, is a clear case of life mirroring art.

While computers are very good at telling the difference between excited and calm, they are not very good at the difference between excited-happy and excited-angry-or-upset. "They confuse a shriek of joy and a shriek of terror," she explains.

As for facial expressions, the hardest part for the poor machine is finding the person's face and following it about. "The camera is fixed to the computer and it just isn't that fast at grabbing images," says Prof Picard. "With current technology, if you hold still and don't change the lighting, a computer can recognise the difference between a smile and a frown." It might well think you are smiling when in fact you are scratching your nose, or frowning when you are fiddling with your ear, but if you really want to confuse it, try having lunch at your desk, or chatting to a colleague. The smile/frown recognition is based on the computer spotting various bits of your face moving up or down and the movements involved in chomping a tuna wrap or gossiping animatedly will throw it completely.

As well as voices and faces, there are other possibilities. "We're building a lot of crazy gizmos to see which people will prefer," says Professor Picard. "We interviewed a number of people using frustrating software and some preferred an on-screen dialogue box, while others wanted a mouse they could pound on, or something they could squeeze, hit or throw to let the computer know when they were irritated." As well as relieving the operator's feelings, this technology could also be used to let software designers know about glitches in their programs. "The computer probably isn't smart enough to fix itself," says Professor Picard. "But it can gather information to pass on to the programmer."

It's also possible that computers will be able to work out how their humans are feeling using sensors that check levels of arousal by measuring physical symptoms like skin conductivity or muscle tension. IBM is working on a mouse that incorporates sensors that measure heart rate, temperature, skin conductivity and clicking pressure. Media Lab is currently testing a portable CD player, which can sense skin conductivity - a good indicator of agitation levels. "You can choose your own music, or the player can select randomly - or it can pick things in accordance with your mood parameters," explains Professor Picard. "You can instruct it to go for rousing mode and it will play peppy music until it senses that you are aroused to a certain level, or if you want it could pick music to calm you down."

While computers could use similar technology to gauge their operators' stress levels, she does not advocate them ever using jolly tunes to try to soothe these frazzled users. "We have to think carefully. We don't want the computer to manipulate the mood. If your computer just played happy music it would drive you nuts," she rightly observes. "I don't mind the computer making suggestions. The idea is to think of what you would expect an intelligent friend or co-worker to do and see if you can get the computer to do it."

A sympathetic pat on the shoulder and a hot cup of tea with a chocolate biscuit are, sadly, out of the question, however empathetic your electronic companion might be. And it's unlikely that a computer that cares will be installed on a desk near you in the very near future. All these projects are still at the research stages. "Some things will be there in the next few years, others will take decades," says Prof Picard. And, she says, there is no need to fear a computer with an agenda of its own. "HAL, the computer in 2001: A Space Odyssey, seemed to have emotions and express them, and that was kind of dangerous."

HAL, however, is nothing to be scared of - even the most sophisticated of computers can't think. "Computers can seem to have emotions, but they can communicate without understanding," says Prof Picard. "After all, the Mac has been smiling when you boot it up since 1984, without ever feeling happy! Even if a computer can recognise the external manifestations of your emotions, it can't see the thoughts behind them. Computers can't get into your mind."

`Affective Computing' by Professor Rosalind Picard, Massachusetts Institute of Technology Press, $29.