Volume 63, Issue 6, 1627-1644
Functional Magnetic Resonance Imaging (“fMRI”) technology produces a four-dimensional map of brain activity, such as perception, memory, emotion, and movement. fMRI scans track the flow of blood to the various regions of the brain in real time and reveal the subject’s response to particular stimulus. For example, an fMRI scan might reveal blood flow to a subject’s memory center in response to a picture of the house in which she was raised. On the one hand, this technology seems to produce a model of a physical attribute and offer insight into the workings of the human brain. On the other, fMRI scans seem to read our minds and disclose our thoughts. The full range of applications of fMRI technology is just emerging, but proponents have already sought its admission in court as a type of lie detector or credibility builder. If fMRI scans are incorporated into the government’s investigatory process, constitutional safeguards should be in place to protect the fundamental right of privacy and an individual’s freedom to decide whether to assist the state. This Note proposes that the results of fMRI scans are testimonial evidence: first, because the scans reveal the subject’s knowledge or beliefs, and second, because this classification ensures that fMRI scan results are afforded the protection of the Fifth Amendment. If fMRI scans are privileged under the Fifth Amendment, the government cannot compel an individual to submit to the scan and reveal the contents of her mind.