Whether neuroimaging, specifically fMRI, as lie detector technology, would be admitted in courts, either federal or state in Virginia through expert testimony

Admissibility of FMRI

Introduction

In 1993 , the Supreme Court suggested four questions that judges should consider in determining whether expert testimony on scientific evidence will be admissible in the courtroom or not . The following are the test questions

Is the evidence based on a testable theory or technique

Has the theory or technique been peer reviewed

Does the technique have a known error rate and standards controlling its operation

Is the underlying science generally accepted

This will discuss neuro-imaging , specifically functional magnetic resonance imaging , as a lie detector

test and its admissibility in evidence

What is FMRI

Functional magnetic resonance imaging , or FMRI , is a technique for measuring brain activity . It works by detecting the changes in blood oxygenation and flow that occur in response to neural activity - when a brain area is more active it consumes more oxygen and to meet this increased demand blood flow increases to the active area . FMRI can be used to produce activation maps showing which parts of the brain are involved in a particular mental process (FMRIB Center

This is how it works : oxygen is delivered to neurons by haemoglobin in capillary red blood cells . When neuronal activity increases there is an increased demand for oxygen and the local response is an increase in blood flow to regions of increased neural activity . Haemoglobin is diamagnetic when oxygenated but paramagnetic when deoxygenated . This difference in magnetic properties leads to small differences in the MR signal of blood depending on the degree of oxygenation . Since blood oxygenation varies according to the levels of neural activity these differences can be used to detect brain activity . This form of MRI is known as blood oxygenation level dependent (BOLD ) imaging (id

It is claimed that through this process , FMRI can be used as a lie detector test . The question now arises that should the FMRI be used as a lie detector test , will the results be admissible in evidence in our courts of law in light of the Daubert ruling ? This will try to answer this question by testing FMRI against the four questions set up by the Supreme Court in the said decision

Is FMRI a testable technique

The Supreme Court , in discussing how evidence should pass this test the judge must ascertain whether the reasoning or methodology underlying the testimony is scientifically valid and of whether that reasoning or methodology properly can be applied to the facts in issue . A key question to be answered in determining whether a theory or technique is scientific knowledge that will assist the trier of fact will be whether it can be (and has been ) tested (92-102 . The main concern of the Supreme Court here is the reliability of the technique and reduction of falsifiability

FMRI is one of the most recently developed forms of neuroimaging but the idea underpinning the technique - inferring brain activity by measuring changes in blood flow - is not new (FMRIB Center . The technique , however , is relatively new . FMRI still has not gained acceptance...