13 December 2011

Scientists’ growing understanding of the brain will definitely impact on the law in the future however at present the use of some neuroscientific findings as evidence in a court of law should be approached with great caution according to a report published by the Royal Society.

The Royal Society looks at where neuroscience might be able to offer insights to the law and current limits to its application. The authors emphasise the need for a forum in the UK which would bring together neuroscientists and legal professionals to discuss advances and identify practical applications.

Areas of interest considered in the report include the use of imaging studies as independent evidence of the severity of someone’s pain for civil cases, the possibility of using brain scans to ‘read minds’ and determine if someone is telling the truth, and how neuroscience might add to the evidence base in cases of Non-Accidental Head Injury (NAHI) or Shaken Baby Syndrome (SBS) in infants. The report also raises concerns that the age of criminal responsibility in the UK is unreasonably low.

Brain Waves Module 4: Neuroscience and the Law, which was written by a group of experts in neuroscience, law, psychology and ethics, says that claims that murderers can be identified by imaging studies of their brains before committing the crime, or that there is a gene ‘for’ psychopathy or for violent and antisocial behaviour are completely wide of the mark. It does however suggest that neuroimaging and behavioural genetics may in the future be used, together with existing approaches, as part of risk assessments when determining sentencing and probation for convicted individuals.

The report discusses how neuroscience is providing new insights into brain development revealing that changes in important neural circuits underpinning behaviour continue until at least 20 years of age. This raises important issues related to the age of criminal responsibility in England which is ten. The report notes that some experts in the field of neuroscience are concerned that this is unreasonably low.

According to the report, functional imaging methods now make it possible to identify which brain regions become active during a painful experience and allow us to relate this to an individual’s specific pain experience. The authors say that whilst these technologies are not at present able to tell us whether a particular individual is genuinely experiencing pain or is malingering, they are close, and it is important that developments are relayed to the legal profession and to medical expert witnesses. Such techniques are currently being used for diagnostic purposes to guide treatment and surgery so it is conceivable that this information will one day be used in courts of law.

The potential to detect deception is one of the more commonly cited areas in which neuroscience may impact on the law. The report’s authors point to functional imaging experiments with students which have shown differences in neural activity when they are telling the truth and when they lie but give a number of reasons why for the foreseeable future reliable functional MRI (fMRI) lie detection is not a realistic prospect, including the fact that people can be taught countermeasures that will defeat an fMRI lie detector.

A key recommendation of the report is that further research be undertaken to characterise Non-Accidental Head Injury (NAHI), or Shaken Baby Syndrome (SBS) and distinguish it from natural causes. Current neuropathological research suggests that existing methods of forensic diagnosis may be insufficient in determining causation and has also identified potential indicators to strengthen diagnoses.

Professor Nicholas Mackintosh FRS, chair of the working group that wrote the report and Emeritus Professor at the University of Cambridge, says:

“Understanding how the brain works gives us an insight into the mental processes that underpin human behaviour and as the law is primarily concerned with regulating people’s behaviour it make sense that the one may influence the other at some point down the line.

There’s no doubt neuroscience will provide some startling revelations about human behaviour but we can’t be allowed to get ahead of ourselves. At this point, our priority needs to be making sure that advances in neuroscience that may have impact on the law are communicated properly to professionals at all stages of the legal system so that when it becomes appropriate, neuroscience is used in court to the benefit of all involved.”

Read the full report.