Is a picture worth a thousand words? Neuroimaging in the courtroom.

Neuroimaging has advanced our understanding of how the living brain operates, providing structural and functional images of both healthy and diseased brains. This technology pervades today’s society, particularly affecting the legal arena. Some judges argue that scientific evidence, which offers insight into the offender’s mental state, is crucial because it is the only means of determining whether an offender’s punishment is proportional to his crime. Other judges argue that “objective” evidence does not “wholly determine the controversy,” and focus instead on their duty as gatekeepers to independently evaluate scientific evidence. If courts use brain images to make their culpability determinations more objective and sound, these images must meet pertinent legal standards and shed light on medical conditions. For neuroimaging to meet these legal and medical standards with scientific integrity, scientists must convincingly correlate the dynamic images in a person’s brain with the way the person is thinking or acting at that moment. With respect to understanding the relationship between the brain and certain behaviors, the state of scientific knowledge is nascent, but promising. The more complex and specific the behavior examined, the more speculative the connection. For example, violence is a multifactorial and socially driven behavior that is not likely reducible to a unitary brain function or region. At present, there is no specific area of the brain to which aggression and violence are singularly ascribed. Brower and Price stated, “The evaluation of research on the neurobiology of violence demands conceptual clarity, along with careful analysis of methods and data to prevent misunderstanding and