Weighing the admissibility of fMRI technology under FRE 403: for the law, fMRI changes everything - and nothing.

• Author: Amirian, Justin
• Position: Introduction through III. fMRI Under 403 A. FRE 702's Probative Value Factors, p. 715-743 - Functional magnetic resonance imaging; Federal Rules of Evidence

Introduction I. Background A. Lie Detection 1. Executive Function 2. Anatomy of a Lie 3. Deception Detection Techniques B. Lie Detection Technology 1. Polygraph 2. Brain Imaging a. Lesser Used Technologies b. Functional Magnetic Resonance Imaging (fMRI) II. Relevant Evidentiary Rules A. Rules 1. Authentication 2. Rule 702 3. Rule 403 B. Technology's Evidentiary Significance 1. The Polygraph 2. Brain Imaging III. fMRI under 403 A. FRE 702's Probative Value Factors 1. Testability 2. Peer Review 3. Known/Potential Rate of Error 4. Existence/Maintenance of Standards 5. General Acceptance in the Scientific Community B. Unfair Prejudice: Will the Jury Overvalue This Evidence? 1. Jurors Will Not Overvalue Neuroimaging Evidence a. Gurley & Marcus (2008) b. Weisberg et al. (2008) c. McCabe & Castel (2008) d. McCabe et al. (2011) e. Greene & Cahill (2012) f. Schweitzer et al. (2011) 2. Jurors Currently Overvalue Other Types of Evidence a. Eyewitness Testimony b. Forensic Evidence C. Confusing the Issue 1. Juror Problems 2. Judge Problems 3. No Problem: Jurors Are on the Same Page as Judges 4. Paternalism 5. The Great Legal Engine: Cross-Examination D. Misleading the Jury: The Jurors Are Already Misled 1. Credibility Assessment a. Credibility Assessment Using Demeanor b. Credibility Assessment Using Context IV. fMRI May Change Everything, but FRE 403 Changes Nothing A. fMRI Images Remain Innocent Until Proven Guilty B. Jurors Overvalue Other Types of Evidence C. Justice Thomas's Scheffer Opinion Is Not Binding D. The Jury Needs Whatever Help It Can Get E. Additional Suggestions to Lessen Potential Harmful Impacts of fMRI Deception Detection F. The Admission of fMRI Will Only Improve Its Reliability Conclusion INTRODUCTION

Assuming that society and the justice system possess an inherent interest in truth, (1) what social benefit justifies what would arguably be the most intimate invasion of privacy possible? (2) What is the role of the jury, and what purpose does it serve within the larger confines of our justice system? (3) Is it possible to utilize lie detection technology without displacing the jury's role and purpose? (4)

What does it mean for evidence to be reliable? How reliable must evidence be before we allow it to be considered by the jury? Would that level of reliability be different if the evidence was only shown to a judge? Does the requisite level of reliability differ for different kinds of evidence? (5) In determining reliability, why must a judge use scientific norms to assess legal relevance? (6) If lie detection becomes sufficiently reliable under legal standards, will it be admissible in court?

These are but a few of the questions that the advent of deception detection using functional magnetic resonance imaging (fMRI) has raised. This Note only purports to definitively answer the last of these questions: whether lie detection, if it becomes sufficiently reliable under legal standards, will be admissible in court, while shedding light on at least some of the others. As an established scholar in the field of neuroimaging recently pointed out, the comparisons of this technology to the mind-reading lore of 1984, Minority Report, and Inception are premature, generating debates that are "too untethered from scientific reality." (7) This technology, however, is more likely than any others that have come before it to reliably distinguish a person's truthful statements from deceptive ones. (8)

Part I of this Note provides an overview of the anatomy of a lie and the technologies used to detect them. Part II discusses the relevant evidentiary rules governing the admissibility of such technology, as well as the evidentiary significance of these technologies under these rules. Part III considers the admissibility of fMRI deception detection technology once it becomes reliable enough to satisfy the standards governing scientific expert testimony. Part IV concludes the discussion, finding that this technology's probative value will not be outweighed by any potential for undue prejudice, or to confuse or mislead the jury.

1. BACKGROUND

   1. Lie Detection

      Humans have sought the ability to distinguish the truth from a lie from time immemorial. Lies take many different forms, and different techniques and technologies have been developed to try to measure these different lies. The most famous lie detection technology is the polygraph, but new technology that measures the brain's activity now offers the greatest potential to be of use for the legal system.

      1. Executive Function

         Evolution has endowed humans with several capabilities that separate us from our animal kin. Of these, perhaps the most important is the growth of a part of our brains called the prefrontal cortex, which has grown at a faster rate in homo sapiens than in the rest of the animal kingdom. (9) The prefrontal cortex is the crux of what separates humans from our evolutionary brethren, (10) allowing us to engage in a broad range of behaviors encapsulated by the term "executive function." (11) These behaviors include problem-solving, modifications in behavioral responses to stimuli, planning, and behavioral inhibition--allowing humans to conform to society's expectations. (12) Although deception predates the evolution of language, (13) the evolutionary growth of the brain's prefrontal cortex, and consequential advent of language, led to an "efflorescence of [deception] complexity." (14) This executive function system works in conjunction with other parts of the brain, such as those that deal with instincts like breathing and sleeping. (15) Crucially, for the purposes of this Note, the executive function interacts with the parts of the brain that deal with memory. (16)

      2. Anatomy of a Lie

         Truth is not a binary concept--it lies on a wide spectrum. (17) There are theoretically three types of lies. (18) First, when a subject, who knows of some fact X, is asked if he knows of X, and he feigns ignorance of this fact, that is called "guilty knowledge." (19) The second category is when a subject makes a genuine assertion of truth that is not objectively true--these assertions are sometimes "mistakes" or "delusions." (20) The third, and possibly most important, category is when a subject knows of some fact X, yet when asked if he has any knowledge of X, he instead responds with some falsehood Y. (21) The key difference between the latter two categories is the intent of the subject to deceive in the third category, as compared with the honest assertion of subjective truth in the second. (22) In this third category, the subject must suppress truth X from his memory, while simultaneously constructing falsehood Y. (23)

      3. Deception Detection Techniques

         The first of two techniques commonly used to detect deception is the Control Question Test (CQT). (24) This test theoretically allows an examiner to detect deception by comparing a subject's physical responses to different types of questions. (25) An examiner usually asks an innocuous "control question," such as the subject's name, to get a baseline reading of the subject's physical response while being honest and truthful. (26) Then the examiner asks pointed and relevant questions, which have to do with the topic of the test. (27) Deception is inferred when physical reactions are stronger or different in the "relevant" condition than in the "control" condition. (28)

         Another commonly used method to detect deception is the Guilty Knowledge Test (GKT), (29) which is also referred to as the...