Issues in Interdisciplinarity 2019-20/Truth in Lie Detection through Neurolaw

Neurolaw combines law andneuroscience and explores how neuroscientific findings are applied legally. At the centre of neurolaw lies the human brain as a critical factor in legal decision making and policy. Thus, neurolaw uses neuroscientific data for a better understanding of human behaviour to achieve a more accurate legal system. Within a law context neuroscience is applied in subfields such as health law, constitutional law, employment law, or criminal law. Issues addressed range from potential implications of cognitive impairment on sentencing tonootropics to questions regarding techniques employed to gather neuroscientific data.

Introduction

Techniques in Neurolaw

Neurolaw predominantly relies on brain imaging methods such as PET and fMRI. These techniques explore aspects of human cognition including intention, morality, and decision making. PET and fMRI acquire data about brain activity during a specific perceptual or cognitive task. Both measure time-dependent changes in local blood flow to determine the most active brain areas.

Lie Detection

Brain areas implicated in deception

Since the legal system often relies on witness accounts, it is important that those accounts are credible. Thus, central to the field is differentiating truth from lies and finding appropriate methods to do so. Different technologies for lie detection such as polygraphs and more recently fMRI data have since been considered. A polygraph is a device measuring autonomic body responses including heart rate, respiration, blood pressure and galvanic skin reactions in response to specific questions presented to a person. fMRI lie detection rests on the assumption that cognitive processes, including deception, are reflected by brain physiology. Brain regions such as the IFG, IPL, MFG and SFG have been implicated in lying.

However, the controversy about using neuroscientific lie detection technology is ongoing and it is likely that interdisciplinary epistemological differences concerning truth lie at the centre of the debate.

Truth in Neuroscience & Law

Truth in Neuroscience

Neuroscience uses positivism and interpretivism when approaching truth.

Positivism asserts that truth is exclusively verifiable through experimentation, observation and logic. Neuroscientists conduct research through observing brain activity using MRI scans, computerised 3D models and experiments involving cells and tissues to develop new treatments. As neuroscientists approach truth objectively by observing and experimenting, neuroscience is predominantly positivist.

Interpretivism emphasises qualitative analysis, employing various methodologies to reflect multiple aspects of an issue. For example, as feelings reflect the ability to subjectively experience states of the nervous system, it is difficult to study them empirically as direct metrics cannot quantify changes unambiguously. Thus, indirect methods based on theoretical inferences are used. The subjective nature of interpretivism facilitates the understanding of subjective phenomena.

Truth in Law

While law uses positivism, it also relies on social constructionism when approaching truth.

Positivism is used in judicial decision making. In a court of law, evidence is introduced to a judge or jury as proof; with admissible evidence being reliable documents, testimony and tangible evidence relevant to the case. Empirical facts and logic are important legally, such as the proof of a defendant's guilt beyond reasonable doubt.

Social constructionism emphasises that "truth" is constructed by social practices, human interactions and language use. In criminal law, the legality of behaviour lies in its social response rather than its content, with behaviours criminalised through social construction. The legality of behaviour can be changed by social movements; while criminality is perceived differently across cultures and time. As crime is constructed socially, social constructionism is useful in understanding truth in law.

While neuroscience and law both use positivist views, the interpretivist aspects of neuroscience are distrusted in a legal context, resulting in debates such as the admission of fMRI lie detection evidence in court.

Conflicting Truth in Lie Detection

Case Study

Example of fMRI images of the brain

United States v. Semrau illustrates the difference in interpreting truth between law's positivism and neuroscience's interpretivism. To convict the plaintiff of defrauding the healthcare benefit programme, it was necessary to prove that Semrau acted knowingly. Semrau’s appeal presented a fMRI lie detection test, testified by Dr. Steven J. Laken, CEO of Cephos Cooperation, a company that claims it uses “state-of-art-technology that is unbiased and scientifically validated” in its investigation services.

Tension in Views of Truth

United States v. Semrau shows that using fMRI data as evidence to verify the credibility of people's accounts is controversial. In this case the plaintiff's fatigue affected his brain scans causing inconsistencies in results. This reflects a more general issue of using fMRI data in a legal context. Research on lie detection and conclusions gathered from it are usually generated in a controlled experimental setting. However, the conditions under which people try to detect lies in court are very different from the conditions usually employed in scientific experiments. Therefore fMRI data may not have sufficient external validity in court. For instance, there is no perfect correlation between deception and physiological response, data gathered from arousal patterns can result in false positives and, as it was the case in United States v. Semrau, a person's condition can affect the results. Thus, the possibility of falsifying true narratives through erroneously interpreting empirical data raises legal liability.

Consequently, how truth is presented and interpreted is limited by legal admissibility. The prevailing tension in whether legal or neuroscientific standards should be used to determine the admissibility of brain-based lie-detection in courtrooms stems from the extent to which brain scans can demonstrate that they indeed identify what they claim to be measuring. Brain images have no inherent significance without interpretation. However, when presented as evidence to the jury in the course of a trial, they raise questions regarding the concept of truth in the legal system.

The decision to use fMRI data to prove one's innocence depends on the extrapolation between laboratory results and real life lie detection. If the laboratory results match real life lie detection, the jury may place higher evidentiary value on that fMRI data. In United States v. Semrau, fMRI evidence was excluded due to inconsistencies in tests administered to the convicted and the lack of real world examination of fMRI technology

Conclusion

United States v. Semrau illustrates the controversial views on truth from neuroscience and law: the courts deemed fMRI as lacking in reliability. In law, only evidence that is reliable and relevant is admissible. In neuroscience, interpretivism is necessary to relate the observed phenomenon to human subjective will. Lie detection evidence, which is partially based on interpretivist assumptions, is potentially inaccurate in analyzing people’s behaviors and thoughts, whereas courts require firm empirical evidence for the judicial process.

The interpretivist aspect of lie detection affects its judicial credibility. Thus, the distrust of interpretivist truths in law may be the main cause of the current dilemma: lie detection technology, as an upcoming product of neuroscientific development, is not yet an acceptable method to provide admissible evidence in the legal system.

Nevertheless, as techniques of gathering evidence improve, neuroscientific lie detection may reach a level of reliability that permits its use in judging criminal cases in the future.