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Daubert and Frye: Neuroscience in the Courtroom?

I recently found myself thinking about how we would allow evidence dealing with neuroscience into the courtroom. The question interested me because I wanted to know how our judicial system would differentiate between real and useful evidence versus what may seem no better than allowing a Shaman enter to argue a point based on “evidentiary mysticism”.  What I found was that there are two different legal rules for allowing use of neuroscience evidence. The first is the Frye rule and the second is the Daubert rule. Daubert applies in Federal Courts and in States that have adopted it, while the Frye rule applies in all other courts.


The difference between the texts of the standards can seem nuanced but presents two different outcomes judicially. Joseph T. Walsh has a great primer on the two rules if you would like to explore them more, but the issue that I would like to deal with here is simple and does not require a complete knowledge of both rules. Basically you just have to understand the common interpretation of both rules.

For our purposes Frye states that: “Where novel scientific evidence is at issue, the Frye inquiry allows the judiciary to defer to scientific expertise precisely as to whether or not it has gained “general acceptance” in the relevant field. The trial court’s gatekeeper role in this respect is conservative, thus helping to keep “pseudoscience” out of the court”.

On the other hand Daubert states that: “General acceptance is an austere standard absent from and incompatible with the Rules of Evidence. “Scientific knowledge” must be derived from scientific method supported by “good grounds” in validating the expert’s testimony, establishing a standard of “evidentiary reliability”.

What we are concerned with is that under the latter rule the trial judge acts more as a gatekeeper. In this role s/he acts to keep evidence out of the courtroom, regardless of whether society has deemed it generally acceptable, because lay jurors should not consider neuroscience evidence unless it is deemed relevant and reliable by the judge. At first glance the change in rules stands against the beliefs that I hold. This is because, like most people, I believe that every American citizen is supposed to be guaranteed a right to a jury trial, but with our newer rule a judge can simply toss evidence out based on his subjective valuation of the evidence presented before him. This in effect denies someone a trial on that evidence.

Political beliefs aside we should still evaluate the rules objectively and neuroscience is but one method of looking at them. So what does neuroscience tell us about the two rules? Is a judge better suited to deal with judging neuroscientific evidence than a jury? To me the answer is a clear “yes”. The evidence I have found points to a jury being susceptible to being fooled by such evidence. For example, Weisberg et al. found that non-experts who are given the task to choose between two explanations for a problem view explanations with irrelevant neuroscience information as more satisfying than explanations without (1). McCabe and Castel published similar findings when looking at the effect that actual brain images had on our reasoning. They found that, when presenting articles summarizing cognitive neuroscience, articles featuring brain images received higher ratings with regards to scientific reasoning “as compared to articles accompanied by bar graphs, a topographical map of brain activation, or no image.” (2)

This effect is explained by Jonathan Marks who issued a warning against what J.D. Trout has termed “explanatory neurophilia.” (3) In coining this term Trout warns us that when faced with evidence, of any kind, “the promise of cognitive tractability enhances fluency, but not necessarily accuracy.”(4) Marks uses Troudt’s view to criticize the use of neuroscience in the national security apparatus and issues a warning against the fact that brain images are partly open to interpretation by experts and are ripe for misuse by government officials as a tool of interrogation (5).

Although I find Mark’s and Troudt’s arguments interesting I do not believe that we should be completely dissuade from using neuroscientific evidence in a court of law. This is because as Weisberg et al. found there is a limit to the impact that superfluous neuroscientific information can have on our judgments, and there is also a noticeable benefit to be gained from extended and specific training on the judgment of such explanations (6).  It is clear that neuroscience provides us with a clear-cut case in which the Frye rule as a standard is not as efficient as that of Daubert. This is because Daubert allows the judge to play a greater gate-keeping roll when allowing evidence into the courtroom. The judge, who we hope is an expert in dealing with such evidence, is less likely to face the same explanatory neurophilia which jurors and laymen are victim to. The Supreme Court agreed with this assessment in Allison v. McGhan Med. Corp., 184 F.3d 1300 (1999) when it stated that:

“While meticulous Daubert inquiries may bring judges under criticism for donning white coats and making determinations that are outside their field of expertise, the Supreme Court has obviously deemed this less objectionable than dumping a barrage of questionable scientific evidence on a jury, who would likely be even less equipped than the judge to make reliability and relevance determinations and more likely than the judge to be awestruck by the expert’s mystique.”

Even though giving the judge ultimate deciding authority supports the centralization of decision making in our court system, I wholeheartedly agree with the decision made in the Allison vs. McGhan Med. Corp. case. While as an individual, I typically advocate for a more democratic court system I believe this is a clear-cut situation in which my philosophical beliefs stand against reality.

With that said, however, I am curious. Faced with my arguments above, what do you, the reader, make of it all? Was moving away from Frye a good idea based on what we know of how our brains work? Can you suggest a more efficient way of evaluating scientific evidence?

–Jamie Witter (Guest Writer)

Law Student, Georgia State University

Want to cite this post?

Witter, J. (2012). Daubert and Frye: Neuroscience in the Courtroom? The Neuroethics Blog. Retrieved on
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1. Weisberg, D. S., Keil, F. C., Goodstein, J., Rawson, E., & Gray, J. R. (2008). The seductive allure of neuroscience explanations. Journal of cognitive neuroscience, 20(3), 470-7. doi:10.1162/jocn.2008.20040

2. McCabe, D. P., & Castel, A. D. (2008). Seeing is believing: the effect of brain images on judgments of scientific reasoning. Cognition, 107(1), 343-52. doi:10.1016/j.cognition.2007.07.017

3. Marks, J. H. (2010). A Neuroskeptic ’ s Guide to Neuroethics and National Security. Defense, 1(2), 4-12.

4. Trout, J. D. (2008). Seduction without cause: uncovering explanatory neurophilia. Trends in cognitive sciences, 12(8), 281-2. doi:10.1016/j.tics.2008.05.004

5. Marks, J. H. (2010). A Neuroskeptic’s Guide to Neuroethics and National Security. Defense, 1(2), 4-12.

6. Weisberg, D. S., Keil, F. C., Goodstein, J., Rawson, E., & Gray, J. R. (2008). The seductive allure of neuroscience explanations. Journal of cognitive neuroscience, 20(3), 470-7. doi:10.1162/jocn.2008.20040

Editor’s note: For more information on the McCabe & Castel article, please see our post here.  

Also, the Emory Neuroscience Graduate Students in partnership with Emory’s Neuroethics Program will be hosting a symposium on this topic on May 25th: The Truth About Lies: the Neuroscience, Law, and Ethics of Lie Detection Technologies featuring  Drs. Hank Greely, director of the Center for Law and Biosciences at Stanford Law School, Daniel Langleben, a professor of Psychiatry at University of Pennsylvania and pioneer of using fMRI to detect lies, and Steven Laken, founder, president, and CEO of Cephos; a company that markets the use of fMRI for courtroom lie detection. Stay tuned for more information.


  1. This is a very good summary of a complicated process. What this always brings up for me is the general divide between scientists and laypeople- for example, the Daubert rule assumes that the great majority of people selected for jury duty simply will not have the general scientific knowledge necessary to avoid being "fooled" by scientific evidence. It may be a good rule to follow given the studies you have cited on explanatory neurophilia (and I know there have been similar studies done on other types of forensic science).

    However, as an educator, it doesn't really sit well with me as a long-term solution. First, it creates a gap between the educated judge and the (presumed) less-educated jury. This assumption is fine if we are thinking about legal education, i.e. following the portion of Daubert which says the judge is really determining relevance, which s/he is trained to do. Yet the justification here verges on saying that laypeople, generally, simply do not see as much science in their daily lives as judges do. So, the argument goes, let's just not give them more science they don't understand. This is the second problem- arguments about the admissibility and effect of scientific evidence in jury trials often reinforce the gap between scientists and non-scientists: a gap which exists amongst educated people at all levels.

    So really, the question this raises for me is, is it reasonable to hope that this gap could be closed? Is using the Daubert standard giving up, or is it just a measure we adopt for now until the level of general scientific knowledge and exposure is such that explanatory neurophilia might disappear?


  2. Cyd,

    I'm glad you liked it.

    With regards to your comment about whether or not the Daubert standard was us giving up, or whether or not it was a temporary measure; I wanted to point out that the current solution in the law is never a long-term solution.

    The goal should be progress not perfection as they say, but even with that said how different people measure "progress" differs.

    So to answer your question, based on the values I hold, I believe that the new standard is here to stay until the context in which the legal system resides changes enough to require a new rule. Whether this will be due to the general level of scientific knowledge of society changing is yet to be determined. This is because cultural opinions and other values not based in objectivity can also affect what standards courts adopt.

    As for the gap between scientists and non-scientists I have one suggestion that may serve to assist us in getting around this. Before I get to it though, let me preface it with saying it's just an idea and i'm actually not an expert on civil/criminal procedure.

    I believe that we should have jurisdiction based also on subject matter. For example I envision a system in which we have judges and courts that are specifically charged/trained with judging issues dealing with scientific evidence among other things.

    So for example the Frye rule was first applied to modern neuroscientific evidence in the case of Brian Dugan on October 29, 2009. Dugan was charged with and found guilty of raping and killing: a 10 year old girl in 1983, a 27 year old Nurse in 1984 and a 7 year old girl in 1985. With this guilty verdict in hand the lawyers representing Dugan tried to use fMRI imaging technology in his sentencing hearing. Dugan's lawyers were attempting to use expert testimony to mitigate his sentencing so that he would not be subject to the death penalty.

    The prosecution, in attempting to keep Neuroscientific evidence out of the court room, made the argument that allowing fMRI scans as evidence might bias the jury.

    Faced with concerns along the same lines of Marks and Trout, mentioned in the blog post above, the judge in Dugan's case ruled that the jury would not be allowed to see Dugan's actual brain scans. Instead he/she allowed an expert witnesses, aided by bar graphs and depictions of cartoon brains, to describe them and how he interpreted them.

    In the end Dugan was sentenced to death after the jury returned a unanimous vote against him.

    Unfortunately since the jury deliberations are private, we do not know what role the Neuroscientific evidence played in the jury returning their verdict.

    Taking the Dugan case as an example I believe that the second the challenge was made the primary case should have been put on hold and then there should have been a second case in a court specifically designed to handle evidentiary questions such as this.

    This would give the plaintiff and the defense to then hire council who is also just as specialized to plead their case regarding the evidence.

    The difference between my suggestion and what we have at present in the form of evidentiary/preliminary hearings is the role of the judge. He/She would, at this point, be specifically trained for this kind of issue with emphasis on the judge's scientific background.

    Now a central goal of the judicial system is efficiency so my suggestion would be problematic. This is because litigation would take ages. Fortunately it may also increase the amount of lawyers that are needed in society which would in turn help me to find employment after graduation.

    I hope that helps, but i'm just curious. If you designed a system from scratch what would it look like?


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  4. neuroscience in courtrooms require lengthy discussion to properly understand a case. you might as well hire the services of doctors expert about the topic. this, of course, is complicated for lawyers to understand.
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  5. I agree with Mark's argument, brain images are interpreted by experts and are ripe for misuse by government officials.
    However, neuroscience evidence should not be completely dissuaded in the court of law because we could also get benefits from it.
    There are certain cases which need pieces of neuroscience evidence that is why it is right for the judges to serve as gatekeepers– to keep or toss the evidence out of the courtroom.

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