The hi-tech imaging techniques, most commonly used in medical diagnosis and treatment, have been used in some countries as part of criminal cases to determine brain deficiencies or whether someone is lying. They can also be used to assess people's likes and dislikes in response to advertising and marketing, and even voting preferences.
The technology has advanced to the point where, when viewed by special scanners, different areas of the brain "light up" when they function, with this knowledge interpreted to "read" someone's thoughts.
Scottish politicians are now calling for a debate on the best way to regulate the technology to protect Scots amid concern that the emerging uses of the scans could threaten privacy and civil liberties, as well as pose health risks.
The call comes after a conference during the summer raised fears about the accuracy and ethical issues linked to new imaging techniques.
The Scottish Universities Insight Institute in Glasgow has since produced a document outlining questions raised about the impact of brain imaging on society. The experts concluded that there was "little scientific validity for current use of imaging in law, commerce or security". They said that a watchdog to monitor and comment on emerging uses for imaging "would be valuable for society".
The findings have been examined by the Scottish Parliament's think-tank, Scotland's Futures Forum. Now Labour MSP Helen Eadie has tabled a motion calling for a debate on the issue.
The motion acknowledges "the potential benefits and dangers for Scotland in the use of emerging brain-scanning technologies, particularly in areas other than the health arena". It adds that "there is a need to debate the best regulatory and legislative frameworks to protect Scottish citizens".
Labour colleague Dr Richard Simpson backed the calls. "One of the concerns is that they are introducing these imaging and scanning techniques and there needs to be a debate about the ethics of it and who is going to manage that - what it actually does, how accurate it is and what effect it has on people.
"If you have a scan done and are showing some reduction in brain size, that could affect your insurance. I think it is partly to say who is regulating this and are we regulating it properly. We need to have a debate on the overall ethics of it."
In recent years, countries including the US and India have taken the use of scanning technology out of the hospital and into the legal world. In one case in the US, functional magnetic resonance imaging (fMRI) was used as mitigation during sentencing to try to show a killer was a psychopath who could not control his killer urges. On this occasion, the jury still decided on the death sentence.
In other examples, commercial companies have been set up offering brain imaging services in areas such as lie detection, which could be used by companies on employees.
Simpson said if these scans were to be used in legal cases, they had to be totally accurate and reliable. "We need to ask the questions about how this is to be used and in what circumstances, and will citizens be protected from error and abuse of this new technology.We are not opposing the technology, but we are saying we need a clear debate about the ethics of it."
Burkhard Schafer, professor of computational legal theory at Edinburgh University, said there were serious doubts that results were reliable in some uses of the technology.
He said if important decisions depended on scans, the results had to be based on proper academic testing. "Even if the results were reliable, they need to be communicated to the decision maker - judge or jury, for instance - in a way that they can interpret them correctly," Schafer said.
"The statistical nature of the science makes this a difficult task, and robust standards need to be developed.
"We have concerns that decision makers will over-estimate the relevance and importance of the results, simply because they come from 'scientific experts' and have pictures attached to them."
Schafer said they were also concerned that premature use of the technology would bring it into disrepute. "Scotland has an excellent infrastructure for neuroimaging research, and world-leading experts in the field. Many of the results can be really important for the future, for example diagnostic or treatment of mental illness and catering for an ageing population. Premature use of the results by 'cowboys' could cause a damaging backlash against a technology that has the potential for great medical, and commercial, benefits."
Another concern about the increased use of scans is the potential health implications.
On the ethical side, experts question what should be done if someone carrying out a scan for non-medical reasons spots something which might indicate an illness, such as a brain tumour.
Joanna Wardlaw, professor of applied neuroimaging at Edinburgh University, said: "Failure to recognise and deal with these properly can lead to a lost opportunity for early treatment or raise undue alarm if not handled properly. Most non-medical researchers are not competent to recognise these or interpret them correctly; even among medics, many non-radiologists are not competent to deal with them. The non-medical users seem to be completely oblivious to this potentially serious problem."
There are also issues around the safety of people having frequent scans as well as dangers if MRI scanners are not used properly.
Schafer said use of the technology in areas outside of medicine and research had so far been mostly limited to countries outside Europe.
But he added: "It is only a question of time before this also becomes an issue in the UK."