Flexible Versus Fixed Battery

Readers of my blog are familiar with the debate that has been going on for years regarding the validity of the fixed versus flexible neuropsychological batteries. In 2007, Erin D. Bigler, Ph.D. published his article in the Archives entitled “Motion to Exclude”. As outlined in that article, Dr. Bigler used the Archives as a public forum “to inform the field of neuropsychology how attorneys use neuropsychological publications and verbatim quotes in court-filed documents in order to argue their legal position for excluding neuropsychologists’ clinical opinions.” The reason behind Dr. Bigler’s decision to publish this article stemmed from a case in which he served as a plaintiff’s expert and had his methodology of using a flexible battery approach attacked by defense counsel who utilized articles published by Hom (2003) and Russell, Russell & Hill (2005) to support the argument that the Halstead-Reitan battery was the only acceptable neuropsychological measurement to be used in the courtroom.

In response to Dr. Bigler’s outstanding article, Russell (2007) and Hom (2008) wrote commentaries “critiquing” Dr. Bigler’s article. This new November/December 2008 issue contains Dr. Bigler’s response to the Russell and Hom commentaries. Bigler makes clear that the flexible test battery approach is scientifically valid and certainly would meet the scientific validity standard of either Frye or Daubert.

Also contained in this outstanding issue of Archives is an article by Glenn J. Larrabee, Ph.D. entitled “Flexible versus Fixed Batteries in Forensic Neuropsychological Assessment: Reply to Bigler and Hom.” In this article, Larrabee discusses the use of both a flexible approach and the Halstead-Reitan battery and its admissibility in forensic cases. Larrabee concludes in his article that “the flexible battery would certainly meet the general accepted standard of Frye and that both approaches should meet the main Daubert criteria.”

These two articles, along with the recent New Hampshire Supreme Court decision in Baxter v. Temple should put this debate to rest and motions to exclude the testimony of those neuropsychologists who utilize the flexible battery approach should end.

For neurolaw attorneys who retain neuropsychologists who utilize a flexible test battery approach, these two articles are a must read. Halstead-Reitan Neuropsychological Battery – Does it Meet Daubert?

While the Bigler and Larrabee articles discussed above support both the use of the flexible battery approach as well as the Halstead-Reitan fixed battery in forensic neuropsychology, the issue is still swirling as to whether in fact the Halstead-Reitan neuropsychological battery in today’s world does and would in fact meet the Daubert challenge.

As Dr. Bigler discusses in his most recent article, the HRB was “developed, standardized and validated in an era that can only be described as rudimentary.”

When the HRB was developed, subjects utilized had known neurological and neuropsychological deficits medically verified. At the time that HRB was developed, it was the accepted medical view that those who sustained mild traumatic brain injury, a term not even recognized back then, fully recovered shortly after being concussed. Since these patients with mild traumatic brain injury were obviously excluded, the HRB is clearly less sensitive to patients with MTBI. Since the development of the original HRB method, “there has been no re-norming, no re-standardization nor any co-norming by contemporary neurodiagnostic methods.” (Bigler, 2008.)

According to a study by Sweet (2006), referenced in the Larrabee article, a survey of practicing neuropsychologists regarding their basic assessment approaches found that 76 percent used a flexible battery while only 7 percent used a standardized battery such as the HRB. Thus, one can make the strong argument that the HRB is not a widely-accepted approach in the neuropsychological community. The Larrabee article also makes a strong argument that there is no known error rate for the HRB for many patients who sustained traumatic brain injury, raising the question of whether it would satisfy Daubert.

As stated earlier, while both Larrabee and Bigler do not suggest that the HRB would fail the Daubert standard, their articles strongly support that argument.