Who Speaks for Neuroscience? Neuroimaging Evidence and Courtroom Expertise

This 2018 law review article by Jane Campbell Moriarty and Daniel D. Langleben examines the critical question of which professionals are qualified to testify about neuroimaging evidence in court. Using criminal mental health cases as a template, the authors analyze the complexity of expertise requirements across medical, scientific, and legal dimensions, offering policy recommendations for better regulating neuroimaging testimony through clearer qualification standards.

This is a legal and policy analysis employing interdisciplinary examination of legal precedent, medical practice standards, and scientific principles. The authors review expert testimony standards, analyze medical specialization requirements, examine criminal cases involving neuroimaging in mental health contexts, and develop policy recommendations grounded in both legal requirements and clinical expertise.

This interdisciplinary analysis addresses the overlooked question of expert witness qualifications for neuroimaging evidence in courtrooms. The authors examine legal standards under Federal Rules of Evidence 702, medical specialization requirements, and criminal cases involving neuroimaging in mental health contexts. They find no clear standards exist for determining professional qualifications to interpret brain scans, creating risks for justice and scientific integrity. The paper offers policy recommendations to address expert competence issues as neuroimaging evidence increasingly enters criminal and civil cases.

The lack of clear qualification standards for neuroimaging expert witnesses poses significant risks to legal proceedings and highlights the need for policy reform to ensure appropriate expertise guides jury interpretation of complex neuroscientific evidence.

Background & Context

As neuroimaging evidence—including functional MRI (fMRI), PET scans, and SPECT imaging—increasingly enters courtrooms in criminal and civil cases, a critical but often overlooked question has emerged: Who is qualified to testify about this evidence? This 2018 article by law professor Jane Campbell Moriarty and psychiatrist Daniel D. Langleben explores the issue of proper qualifications necessary for expert witnesses who testify about structural and functional neuroimaging evidence, using criminal cases involving mental health as a helpful template to discuss the issues and offering modest policy suggestions to address the question of expert competence.

The paper addresses a significant gap in legal and scientific practice. While courts have developed standards for admitting scientific evidence through cases like Daubert v. Merrell Dow Pharmaceuticals, there are ongoing concerns about neuroimaging evidence: issues related to the quality of the underlying science; the potential for an inferential leap from data to courtroom evidence; the lack of recognized clinical use of some neuroimaging technologies; and the problems of appropriate expertise. The question of who should interpret brain scans for juries—radiologists, neurologists, psychiatrists, psychologists, or other professionals—has profound implications for justice and scientific integrity.

This work is part of a broader scholarly dialogue between the authors, who previously collaborated on seminal analyses of fMRI lie detection and neuroimaging admissibility. Published in a symposium honoring evidence scholar Paul C. Giannelli, the article reflects growing recognition that neurological evidence is increasingly used in criminal cases to argue that a defendant is less responsible for their behaviour, is not competent to stand trial or should receive a reduced punishment for the crime, yet neurologists are rarely involved in such cases despite having the expertise to help inform these decisions in court.

Research Design & Methodology

This is a legal and policy analysis rather than an empirical study. The authors outline the nature of the problem and explain some of the complexity of the question of expertise as a matter of medicine, science, and law, using criminal cases involving mental health as a helpful template to discuss the issues. The methodology involves interdisciplinary examination drawing on legal precedent, medical practice standards, and scientific principles.

The paper employs several analytical approaches to address expert qualifications:

• Review of legal standards for expert testimony under Federal Rules of Evidence 702 and relevant case law
• Analysis of medical specialization and training requirements across neuroscience-related fields
• Examination of criminal cases involving neuroimaging evidence in mental health contexts
• Comparative assessment of different professional qualifications (radiologists, neurologists, psychiatrists, neuropsychologists)
• Policy recommendations grounded in both legal requirements and clinical expertise

The authors bring complementary expertise to this analysis: Moriarty is a leading evidence law scholar who has extensively written on forensic science and neuroimaging admissibility, while Langleben is a psychiatrist at the University of Pennsylvania with dual training in radiology and nuclear medicine who pioneered fMRI lie detection research. This interdisciplinary collaboration allows examination of the qualification question from both legal and medical-scientific perspectives.

Results & Key Findings

The central finding is that there is no clear standard for determining which medical or scientific professionals are qualified to interpret neuroimaging evidence in court, creating significant risks for both legal fairness and scientific accuracy. The authors identify multiple dimensions of this qualification problem that courts must navigate.

The paper highlights several critical insights about expert qualifications in neuroimaging testimony:

• Specialization matters: Different types of neuroimaging require different expertise—structural imaging (CT, MRI) versus functional imaging (fMRI, PET, SPECT) demand distinct interpretive skills
• Clinical use differs from forensic application: Expertise in clinical neuroimaging does not automatically translate to competence in forensic contexts, where retrospective determinations about mental states are required
• Multidisciplinary knowledge gaps: No single medical specialty possesses complete expertise spanning image acquisition, neural interpretation, psychological inference, and legal application
• Current practice is inconsistent: Courts admit neuroimaging testimony from professionals with widely varying qualifications without systematic evaluation of task-specific competence

The authors provide thoughts about better regulating neuroimaging evidence by focusing on the qualifications of experts and offer modest policy suggestions to address the question of expert competence. The analysis emphasizes that qualification standards must match the specific "task at hand"—whether identifying structural abnormalities, interpreting functional activation patterns, or making inferences about behavior and mental states.

Discussion & Significance

This paper makes an important contribution by shifting focus from the admissibility of neuroimaging evidence itself to the qualifications of those interpreting it. While much scholarship has debated whether neuroimaging meets Daubert reliability standards, Moriarty and Langleben argue that even valid scientific techniques can be misapplied by unqualified experts. Their work suggests that courts' gatekeeping function under Federal Rule of Evidence 702 must extend beyond methodology to expertise.

The significance extends beyond neuroimaging to broader questions about interdisciplinary expert testimony in complex scientific cases. The chapter provides a detailed consideration of neuroscience and neuroimaging evidence in US federal and state courts, while detailing ongoing concerns including issues related to the quality of the underlying science, the potential for an inferential leap from data to courtroom evidence, the lack of recognized clinical use of some neuroimaging technologies, and the problems of appropriate expertise. The authors demonstrate that as forensic science becomes more technologically sophisticated, traditional professional boundaries become inadequate frameworks for determining competence.

The paper's policy recommendations have practical implications for legal practice, medical professional organizations, and judicial education. By advocating for clearer qualification standards tied to specific testimonial tasks, the authors provide a roadmap for improving the reliability of neuroscience evidence while protecting defendants' rights and maintaining scientific integrity in legal proceedings.

Limitations & Considerations

As a legal and policy analysis rather than empirical research, this paper does not provide quantitative data on expert qualification patterns across jurisdictions or measure outcomes associated with different expert qualifications. The recommendations are normative and aspirational, requiring uptake by courts, professional organizations, and legislatures to have practical effect.

Several considerations limit immediate implementation of the proposed reforms:

• The rapidly evolving nature of neuroimaging technology means qualification standards may quickly become outdated
• Defining "task-specific" expertise requires granular distinctions that may be difficult for non-specialist judges to apply
• Practical constraints in smaller jurisdictions may limit access to ideally-qualified experts
• Professional territorial disputes between medical specialties could complicate consensus on qualification criteria

The paper also acknowledges that other forms of neuroimaging, such as nuclear medicine (PET and SPECT) evidence, are often admitted in civil and criminal trials for various purposes, often without proof of meeting Daubert's reliability standard, suggesting that qualification problems exist within a broader context of inconsistent evidentiary gatekeeping.

Practical Applications

For legal practitioners, this analysis provides a framework for challenging or supporting expert qualifications through voir dire examination. Attorneys can use the task-specific competence framework to probe whether an expert's training and experience match the particular interpretations they offer—distinguishing, for example, between reading structural abnormalities and making behavioral inferences. The paper equips lawyers to ask more sophisticated questions about board certifications, fellowship training, active clinical practice, and familiarity with forensic versus clinical applications.

For judges and policymakers, the work offers guidance for developing qualification standards that balance scientific rigor with practical feasibility. Courts can implement preliminary hearings focused specifically on expert qualifications for neuroimaging testimony, separate from general reliability determinations. Professional organizations like the American Academy of Neurology, American Society of Neuroradiology, and forensic psychiatry boards could develop certification or guidelines for forensic neuroimaging testimony. While this paper does not directly address polygraph testing, its framework for evaluating expert competence across technological and interpretive domains offers valuable lessons for any field where complex physiological data requires specialized interpretation for legal purposes.