Putting your brain on the witness stand

This New York Times article explains that although advances in neuroscience have made some changes in the American legal system, those changes only scratch the surface of what is being investigated. In 1992, the defense counsel for a man charged with killing his wife attempted to introduce testimony suggesting that the defendant "should not be held responsible for his actions because of a mental defect — namely, an abnormal cyst nestled in his arachnoid membrane." The judge permitted the defendant to "tell the jury that brain scans had identified an arachnoid cyst, but they couldn’t tell jurors that arachnoid cysts were associated with violence." Since then, brain scans have been admitted to mitigate sentencing in capital punishment cases. Furthermore, as this article sets forth, researchers are using neuroscience to refine functional M.R.I.lie-detection technology so that it can be admitted in court or using such technology to "revolutionize the way jurors are selected." The article ends with these troubling questions: "Can the police get a search warrant for someone’s brain? Should the Fourth Amendment protect our minds in the same way that it protects our houses? Can courts order tests of suspects’ memories to determine whether they are gang members or police informers, or would this violate the Fifth Amendment’s ban on compulsory self-incrimination? Would punishing people for their thoughts rather than for their actions violate the Eighth Amendment’s ban on cruel and unusual punishment?" Scary stuff.