Doctors are aiming to uncover what causes one of the most common mental health problems - social anxiety disorder.
One in 10 people have social anxiety disorder
The condition, which is characterised by a dread of social situations, affects one in 10 people.
The University of Southampton and Royal South Hants Hospital team believe people with the phobia either misread social cues or ignore them altogether.
Researchers said their findings may help improve treatment.
Current treatments vary from counselling, psychological therapy and drugs.
The team will get volunteers to look at images of faces and objects on screen and measure their reactions.
Lead researcher Dr David Baldwin, a senior lecturer in psychiatry at the university, said understanding what caused the condition was paramount to ensuring patients receive better care.
"People with the disorder do not seem to recognise social cues. When people nod, most people would take that as an indication to go on, but people with the disorder may interpret that as a reason to stop.
"It will be interesting to see which of the two they fall into. It is quite likely some will fall into one, with the rest into the other."
Dr Baldwin the disorder affected people "at work, at home, in every aspect of their lives, and it tends to develop when they are 15, which is a crucial age".
Many become depressed and dependent on alcohol, he said.
Marjorie Wallace, chief executive of the mental health charity Sane, said: "We are glad the research is being done, the disorder varies in severity but can really have an impact on people's lives.
"We believe telephone counselling is the most effective method of treatment but it would be great if this research came up with some firm evidence of what does work."