In 1979, the state of Arkansas found Charles Laverne Singleton guilty of murder, and sentenced him to execution. While on death row, he began to show signs of schizophrenia. That led to a stay of execution, as the U.S. Supreme Court had ruled that executing the mentally insane was unconstitutional because they could not understand the reality of, or reason for, their punishment. The decision was made to medicate Singleton, restoring him to "sanity" and thereby making him competent to be killed. He was finally executed by lethal injection in 2004.
These cases and others like them, fascinate scholars who look at the relationship between responsibility and mental capacity. It is a field of law that is evolving rapidly, as research on the brain accumulates.
"Diminishment of mental capacity", is why we don't expect a person with a brain injury, a senior with dementia, or a person with intellectual disabilities, to be fully responsible for their behaviour. But if that capacity is restored does that then make the person responsible again? Also, drugs that affect the brain are being used not just as treatments for disorders, but also for "cognitive enhancement" - to make people "smarter". Would they make people even MORE responsible for their behaviour?
Nicole Vincent has been "obsessed" - her word - with the idea of responsibility for fifteen years. She is associate professor of philosophy, law and neuroscience at Georgia State University. For four years, she was chief investigator on a research project called "Enhancing Responsibility: the effects of cognitive enhancement on moral and legal responsibility", at Delft University of Technology in The Netherlands. She is the editor most recently of Neuroscience and Legal Responsibility, a collection of scholarly essays published by Oxford University Press.
To hear a Ted Talk given by Nicole Vincent on cognitive enhancing drugs and responsibility click here.