Scientist Irene Tracey has been the focus of considerable, and unexpected, legal attention in recent months, as her work on the imaging of the brain's pain receptors brought a steady flow of lawyers to her Oxford University laboratory.
Each has put a similar question: can she show that litigants suing employers over industrial injuries are lying when they say they are in constant pain?
'So far we have said no, we are not ready to carry out such tests. But in a couple of years we will be ready to answer those questions,' Dr Tracey told The Observer .
'We can already tell from brain scans exactly how much pain a person is in at any given time. We can even give a better, more objective rating of that pain than the victim is capable of providing. We have to perfect our techniques before they can be used in court, however.'
This growing prowess is part of a revolution now sweeping medicine. Doctors are using scanners to study brain activity and develop techniques that could soon make breakthroughs in treating patients with depression, schizophrenia and other mental illnesses.
But these scanners - called positron emission tomographs, functional magnetic resonance imagers and near infra-red spectroscopes - are also starting to play roles in everyday life, researchers have realised.
Soon they could be used to tell if a person is lying, to predict that a violent criminal could soon attack again or that they are not really in constant pain as they claim.
Not every observer of these developments is sanguine about such prospects. President Bush's Council on Bioethics is to examine the legal, political and social implications of neuro-imaging. It has decided that opening the minds of individuals to public scrutiny is an unsettling issue, a point backed by academics and lawyers on both sides of the Atlantic.
'It is a question of mind-reading,' said Julian Savulescu, a professor of ethics at Oxford University. 'We have to ask ourselves: should people have the power to do that?'
Neuroscientist Dr Turhan Canli, at Stony Brook University in New York state, can even spot variations in the brain scans of people with different personality traits, such as pessimism, empathy and aversion to risks.
And although it is too early to use these studies in the outside world, a number of people in commercial and government circles want to harness them.
In other words, brain scans could soon be used by schools admissions staff, employers or law enforcement agencies when recruiting. Pilots, detectives and doctors could all be rated by scanners for their pessimism or risk aversion.
Even more alarmingly, Canli has warned that such assessments could be performed while carrying out tests for other purposes. The subject would be unaware why they were being tested.
Another controversial example is provided by the work of Elizabeth Phelps, of New York University, and Mahzarin Banaji of Harvard University. They showed images of African Americans to white people and found that increased activity in an area of the brain called the amygdala was linked to those whites who held strongly negative views about individuals with dark or black skins.
'I don't think we have got to the point where we can say anything about how people will act in the future, but I think we will - it's a matter of time,' Phelps told the journal Science last week.
But is it right to judge someone on unexpressed racist feelings about which they may feel shame or guilt? And could people find their sexual preferences and political affiliations probed and exposed in a similar manner?
'It is clear we are going to have to be very careful about confidentiality issues when these techniques become more widespread,' said Savulescu. 'They have the potential to do good - and great harm.'