On Neuroethics and Law Blog (here) there was reference to a paper giving evidence that scan images do not have the effect on juries that has been reported. Let us hope this is true – scans are far too new and difficult to understand in context, to be used in court if they wield undue influence. I have encountered the opposite view, that scan picture have great influence, but it was with out any evidence, at least where I saw it.
Here is the abstract:
Recent developments in the neuropsychology of criminal behavior have given rise to concerns that neuroimaging evidence (such as MRI and functional MRI [fMRI] images) could unduly influence jurors. Across four experiments, a nationally representative sample of 1,476 jury-eligible participants evaluated written summaries of criminal cases in which expert testimony was presented in support of a mental disorder as exculpatory. The evidence varied in the extent to which it presented neuroscientific explanations and neuroimages in support of the expert’s conclusion. Despite suggestive findings from previous research, we found no evidence that neuroimagery affected jurors’ judgments (verdicts, sentence recommendations, judgments of the defendant’s culpability) over and above verbal neuroscience – based testimony. A meta-analysis of our four experiments confirmed these findings. In addition, we found that neuroscientific evidence was more effective than clinical psychological evidence in persuading jurors that the defendant’s disorder reduced his capacity to control his actions, although this effect did not translate into differences in verdicts.
Schweitzer,N.J., Saks, Michael J., Murphy, Emily R., Adina L., Sinnott-Armstrong, Walter, Gaudet, Lyn M. (2011). Neuroimages as Evidence in a Mens Rea Defence: No Impact Psychology, Public Policy, and Law, 17 (3), 357-393