Boffins at the Massachusetts Institute of Technology (MIT) claim to have developed a device that can tell whether a person being spoken to is becoming bored. 

The Emotional Social Intelligence Prosthesis uses a tiny camera connected to a handheld computer with image recognition and emotion sensing software.

The handheld computer vibrates if it detects that the listener is starting to lose interest in the conversation.

Researchers developed the technology to allow autism sufferers, who often have trouble deciphering social signals, to know whether the person they are talking to is becoming confused or bored with the conversation.

Rana El Kaliouby, from the Media Lab at MIT, told New Scientist that autistic people can fail to pick up on the fact that they are confusing or boring their listeners. "It's sad because people then avoid having conversations with them," she said.

The device is based on software developed by Kaliouby in 2004, in conjunction with the University of Cambridge's Peter Robinson, which tracks the movements of eyebrows, lips and nose, as well as head tilts, nods and shakes. 

The software needs just a few seconds of video to tell whether a person is concentrating, unsure, thinking or in agreement or not.

The system is being developed as a joint effort between Kaliouby and MIT colleagues Rosalind Picard and Alea Teeters.