Computer scientists have developed a new way of cloning facial expressions during live conversations to help us better understand what influences our behaviour when we communicate with others.

This latest technique tracks people's facial expressions and head movements in real time during a video conference and maps these movements to models of faces - producing a "cloned" face. A paper on the United Kingdom-led project was published in the June 2009 edition of the journal Language & Speech.

These facial expressions and head movements can be manipulated live to alter the apparent expressiveness, identity, race, or even gender of a talker. Moreover, these visual cues can be manipulated such that neither participant in the conversation is aware of the manipulation.

Developed by Dr Barry-John Theobald at the UK's University of East Anglia's School of Computing Sciences - in collaboration with Dr Iain Matthews (Disney Research), Professor Steven Boker (University of Virginia) and Professor Jeffrey Cohn (University of Pittsburgh) - the facial expression cloning technique is already being trialled by psychologists in the United States to challenge pre-conceived assumptions about how humans behave during conversations.

For example, it is well known that a person moves their head differently when speaking to a woman than when speaking to a man. The new software has helped show that this difference is not because of your conversational partner's appearance but is instead due to the way they move.

If a person appears to be a woman but moves as a man, others will respond with movements similar to those made when speaking to a man. It is also likely to have application in the entertainment industry where life-like animated characters might be required.

"Spoken words are supplemented with non-verbal visual cues to enhance the meaning of what we are saying, signify our emotional state, or provide feedback during a face-to-face conversation," said Dr Theobald, the leading author of the new paper called Mapping and Manipulating Facial Expression.

"Being able to manipulate these properties in a controlled manner allows us to measure precisely their effects on behaviour during conversation," he added.

"This exciting new technology allows us to manipulate faces in this way for the first time. Many of these effects would otherwise be impossible to achieve, even using highly skilled actors," said Dr Theobald.

The work is funded by the Engineering & Physical Sciences Research Council and the National Science Foundation.

With about 35 staff and 500 students, the University of East Anglia's School of Computing Sciences is involved in many fields of research in business, communications and electronics. There is a consultancy company, Sysco, and several members of staff have close links with industry.

The consultancy offers a range of expertise in the areas of research in which the school has a strong reputation, including avatars (advanced virtual human technology), data mining, image and video analysis; security and network forensics; sound and voice analysis, and urban modelling.