DAVOS SUMMIT:The latest technologies will make mind-reading a thing of the present. Clive Cooksonreports
For the first time in history, it is becoming possible to read someone else's mind with the power of science rather than human intuition or superstition.
The latest brain scanning technology allows researchers to tell whether someone is lying and how they are responding to consumer choices - or even to detect conscious thought in a patient who seems to be in a vegetative state, unable to respond physically to any stimulus.
Functional magnetic resonance imaging (fMRI) shows the flow of blood in the most active parts of the brain, which "light up" in ways characteristic of specific types of mental activity. While structural scanning techniques such as Cat scans can map the anatomy of a patient's brain in great detail, the latest fMRI machines show dynamic changes in thought patterns.
Neuroeconomists, who study the mental processes associated with spending and saving, find fMRI a particularly useful tool.
For example, US researchers reported earlier this month what they said was the first detailed study of people making shopping decisions. The scientists, from Carnegie Mellon and Stanford universities and the Massachusetts Institute of Technology, could predict whether volunteers in the experiment would ultimately choose to buy a product.
The 26 participants were given $20 each to spend on products, which appeared with prices on a computer screen while they lay in an fMRI scanner. If they bought nothing they could keep the money. The scans showed that when the participants were presented with something they were interested in buying, one of the brain's pleasure centres, the nucleus accumbens, was activated.
But when the price was excessive two things happened: a brain region associated with pain, known as the insula, was activated and another part - the medial prefrontal cortex, which is associated with balancing gains against losses - was deactivated. By looking at the activation pattern, the researchers could predict whether the participants would purchase each item before they announced their decision.
Researchers from Ludwig-Maximilians University in Munich reported a similar study in November. They showed images of "strong" and "weak" brands associated with cars and insurance products to volunteers in fMRI machines - and discovered distinct differences in the neural responses.
More controversial is work at several universities and companies to develop fMRI for detecting lies. For example, researchers at Temple University in Philadelphia staged a mock shooting with blank bullets in front of 11 volunteers. Five were then asked to tell the truth and six to lie about the event, when examined with an fMRI scanner and a conventional polygraph detector (which measures lying indirectly through its stressful effects on the body).
Feroze Mohamed, the study leader, said 14 areas of the brain were active during the deception process while only seven areas lit up when subjects answered truthfully. While lying, someone must actively inhibit or conceal the truth, which involves additional parts of the brain. According to Dr Mohamed, fMRI scanning is more accurate than a polygraph test because it detects brain activity directly. But the civil liberties lobby is unhappy about potential abuse of the technology.
fMRI can even be used to track the social interaction between two people, by scanning their brains simulanteously. Read Montague of Baylor College of Medicine, Houston, is pioneering the technique, which he calls hyperscanning. Prof Montague used it recently to show that the brain has a "social agency map" that keeps track of interactions with other people. The research may help psychiatrists understand disorders that are primarily social in nature.
The performance of fMRI is improving rapidly, says Nancy Gillen, head of magnetic resonance imaging for Siemens, the German medical equipment manufacturer - partly as a result of close collaboration between manufacturers and academic users. High-performance machines currently cost about $2 million (€1.53 million) each, she says, "but the cost has to come down".
A big fall in cost will be required before fMRI can be used routinely for the application envisaged by Adrian Owen at the UK Medical Research Council's brain sciences unit in Cambridge - to communicate with patients with severe head injuries, who are unable to respond physically to any stimulus but retain some residual consciousness.
Dr Owen demonstrated last year that two accident victims in a vegetative state, who could not even blink on request, were nonetheless able to replay familiar activities in their mind when asked. Their fMRI brain patterns were unmistakably characteristic of playing tennis and football.
This could be built into a crude communication system. "If a patient wants to say 'yes', I ask her to imagine playing tennis. If she wants to say 'no', I ask her to imagine moving round her house," Dr Owen said. "We could make a cursor on a computer go up or down depending on her answer. This could allow her to select different words, pictures or numbers on the screen, moving towards real-time communication."