Detecting Mens Rea in the Brain

Abstract

What if the widely used Model Penal Code (MPC) assumes a distinction between mental states that doesn’t actually exist? The MPC assumes, for instance, that there is a real distinction in real people between the mental states it defines as “knowing” and “reckless.” But is there?

If there are such psychological differences, there must also be brain differences. Consequently, the moral legitimacy of the Model Penal Code’s taxonomy of culpable mental states – which punishes those in defined mental states differently – depends on whether those mental states actually correspond to different brain states in the way the MPC categorization assumes.

We combined advanced functional brain-imaging technology with new artificial intelligence tools to see if the brain activities during knowing and reckless states of mind can ever be reliably distinguished.

As our experiment indicates, the answer is Yes. So here we provide an overview of our brain-scanning experiment, discuss important implications, and detail several necessary precautions, so our results won’t be over- or mis-interpreted.

Keywords: mens rea, criminal law, mental states, responsibility, culpability, punishment, neuroscience, Model Penal Code, knowing, reckless, fMRI, brain, brain states, brain imaging, brain scan, decision making, cognitive, psychology, neurolaw, law and neuroscience, cognitive

JEL Classification: D87, D81, K14, C91