Opinion ID: 213950
Heading Depth: 2
Heading Rank: 2

Heading: Brain Imaging Evidence

Text: Montgomery intended to introduce expert evidence that a PET scan and MRI showed that her brain had structural and functional abnormalities consistent with the diagnosis of pseudocyesis. Montgomery contends that the district court erred in excluding the evidence at both the guilt and the penalty phases of the trial. She argues that the evidence met the admissibility standards set forth in Federal Rule of Evidence 702 and the Federal Death Penalty Act. She contends that the evidence was highly probative because it provided support for the pseudocyesis diagnosis, bolstered Dr. Ramachandran's opinion, and rebutted Dr. Dietz's contrary opinion. Montgomery argues that the error cannot be deemed harmless, given the critical nature of the evidence. Moreover, she says, the PET evidence should not have been excluded because of her failure to timely comply with the district court's order to produce certain data from the PET scan centers.
Dr. Gur supervised a PET scan of Montgomery's brain. PET scanners measure the level of activity in different areas of the brain. The results of Montgomery's scan revealed elevated activity throughout the limbic system, particularly in the right limbic regions, which are important for emotion processing and memory formation. The limbic system also detects danger and regulates aggression. Montgomery's PET results also showed increased activity in the somatomotor region, including the hypothalamus. According to Dr. Gur, the somatomotor region collects the body sensation. It tells the brain whether you are hot or cold, whether you are hungry or thirsty. It informs the brain of your sex drive, all those sensations that come from the body. Moreover, heightened activity in the hypothalamus has been shown to produce pseudopregnancy in rats. When asked whether it was significant that pseudocyesis is what is called a somatoform disorder, Dr. Gur replied, That's exactly what my thought was when I saw these findings. Based on the PET results, Dr. Gur opined that Montgomery suffered from functional abnormalities consistent with the diagnosis of pseudocyesis. Dr. Gur testified that the purpose of the PET scan was not to diagnose Montgomery with pseudocyesis or any other condition, but to identify any brain abnormalities that might underlie her extreme behavior. Dr. Gur hesitated to say that Montgomery's brain abnormalities caused her to commit the crime. He testified that her brain abnormalities contributed to her actions and that the brain she has may explain at least part of what happened. Alan Evans, Ph.D., conceded that Montgomery's PET results were not inconsistent with the diagnosis of pseudocyesis, but he testified that no causal connection existed between Montgomery's brain functioning and the diagnosis. According to Dr. Evans, Montgomery's PET profile could be consistent with numerous neurological states, both normal and pathological, and thus it is not particularly relevant or important to say it's consistent with pseudocyesis. It's consistent with many, many, many things. Likewise, Helen Mayberg, Ph.D., explained that a treating physician would not request a PET scan to determine whether the patient had pseudocyesis because its results would not be helpful in making the diagnosis. Although the PET scan indicates brain activity, no PET scan pattern indicates pseudocyesis, and PET results cannot be used to predict behavior. Dr. Mayberg testified that the reliance on the study of hypothalamic activity in rats was misguided. When asked whether PET results could be used to identify or diagnose psychiatric disorders, Dr. Mayberg replied unequivocally, no. Drs. Evans and Mayberg also took issue with Dr. Gur's methodology. They claimed that Dr. Gur had calculated the data from the normative population differently than he had calculated Montgomery's data. They were able to duplicate Dr. Gur's calculations only if they employed one method for Montgomery and a different method for the control group. They also expressed concerns over testing conditions and scanner resolution. Following the Daubert hearing, the district court indicated that it would admit PET evidence regarding abnormalities in the somatomotor region of Montgomery's brain. Although skeptical of its reliability, it found that the PET evidence was relevant to the extent that Drs. Ramachandran and Logan would testify that the results showed abnormalities in the area of the brain where they would expect to find abnormalities in a person suffering from pseudocyesis. It found baseless Dr. Gur's opinions about impulse control or aggression and what he identifies as abnormalities in the brain having any causal effect. It also found that Montgomery had failed to show that the results from a PET scan administered in 2007 would reveal the brain's condition in 2004. As set forth earlier, prior to opening statements the district court decided to exclude the PET evidence regarding somatomotor abnormalities. It stated that the evidence had minimal probative value, that the dispute over Dr. Gur's calculations would confuse the jury, that the government's experts were able to duplicate Dr. Gur's results only when they used an invalid methodology, and that the original data from the PET scan center for the control group was unavailable and thus not produced to the government's experts. At the close of the guilt phase evidence and again at the close of the penalty phase evidence, the district court denied Montgomery's renewed requests to present evidence related to the PET scan. [6] We review the district court's interpretation and application of the Federal Rules of Evidence de novo and its evidentiary rulings for abuse of discretion. United States v. Street, 531 F.3d 703, 708 (8th Cir.2008). We may affirm on any ground supported by the record, even if that ground was not relied on by the district court. United States v. Purkey, 428 F.3d 738, 752 (8th Cir.2005). Moreover, even if the evidence was erroneously excluded, the defendant is not entitled to a new trial if its exclusion was harmless. United States v. Bistrup, 449 F.3d 873, 882 (8th Cir. 2006). An error is harmless if it does not affect substantial rights of the defendant. . . and did not influence or had only a slight influence on the verdict. Id. (internal citations omitted). During the guilt phase of trial, Federal Rule of Evidence 702 governs the admission of expert testimony and requires the district court to serve as a gatekeeper to ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable. Daubert, 509 U.S. at 589, 113 S.Ct. 2786. Accordingly, an expert may testify in the form of an opinion or otherwise if scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue and if (1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case. Fed.R.Evid. 702. Dr. Gur's testimony that Montgomery's PET scan showed abnormalities in the limbic and somatomotor regions of her brain was sufficiently reliable to be admitted. The experts agreed that PET scanners reliably measure brain activity, and we have previously noted that [t]here is also no question that the PET scan is scientifically reliable for measuring brain function. Hose v. Chi. Nw. Transp. Co., 70 F.3d 968, 973 (8th Cir.1995). The government experts did not dispute Dr. Gur's testimony that the limbic system regulates emotion processing and that the midbrain, including the hypothalamus, regulates core functions like sleep and sex drive. [7] That Montgomery's PET scan showed abnormalities in areas regulating emotion processing and core functions had minimal probative value. The abnormalities would have been significant only if they had assisted Montgomery in establishing her insanity defense, which was based on Dr. Ramachandran's opinion that Montgomery suffered from pseudocyesis, that pseudocyesis involves the delusion that one is pregnant, and that she was in a delusional or dissociative state when she kidnapped Victoria Jo and killed Stinnett. The PET scan was not used as a diagnostic aid for pseudocyesis, and as conceded by Dr. Gur, the abnormalities do not predict behavior and they did not cause Montgomery to commit the crime. Accordingly, any error in excluding the evidence that Montgomery's PET scan showed abnormalities in the limbic and somatomotor regions of the brain was harmless. Dr. Gur's opinion that Montgomery's PET results showed abnormalities consistent with a diagnosis of pseudocyesis is another matter. Dr. Gur's opinion does not meet Rule 702's reliability requirement because it was at most a working hypothesis, not admissible scientific `knowledge.' See Tamraz v. Lincoln Elec. Co., 620 F.3d 665, 670 (6th Cir. 2010) (citing Fed.R.Evid. 702). Although Rule 702's inquiry is a flexible one, it requires that the principles underlying the proposed submission be scientifically valid. Daubert, 509 U.S. at 594-95, 113 S.Ct. 2786. Scientific knowledge requires more than subjective belief or unsupported speculation. Id. at 590, 113 S.Ct. 2786. Montgomery failed to show that Dr. Gur's opinion was based on scientifically valid principles. Dr. Gur opined that Montgomery's increased hypothalamic and related activation is potentially a source of vulnerability to pseudocyesis (by history). At the Daubert hearing, he cited the scientific study involving rats as evidence of the correlation between increased activity in the hypothalamus and pseudocyesis. Dr. Mayberg, however, described that study in detail. When rats copulate, their hypothalamus gives a pulse of hormone that causes the pituitary to release other hormones, setting the stage for fertilization. The rats may experience a state of pseudopregnancy within two weeks of copulation. Dr. Mayberg explained that the increased hypothalamic activity is temporary and that the hypothalamus does not have a persistent state of activity in the rat experiments. Accordingly, Dr. Mayberg concluded that, even assuming a correlation between a rat and a human hypothalamus, the study was not applicable because (1) Montgomery had been incarcerated for more than two years and thus had not engaged in sexual intercourse and (2) she was not in a state of pseudopregnancy at the time of her PET scan. Dr. Gur made only a passing reference to the study and did not rebut Dr. Mayberg's testimony, other than stating that PET results remain constant unless the patient suffers a major illness or brain injury. The remaining support offered for Dr. Gur's opinion was the fact that the hypothalamus is located in the somatomotor area of the brain and that pseudocyesis is a somatoform disorder. That similarity, however, is irrelevant in the absence of a showing that somatoform disorders are accompanied by abnormalities in the somatomotor region of the brain. Dr. Gur testified that certain areas of the brain affect certain functions, but he was unable to substantiate the opinion that Montgomery's abnormalities were consistent with the diagnosis of pseudocyesis. The district court expected that the defense psychiatrists would testify that Montgomery's PET results revealed abnormalities consistent with her diagnosis of pseudocyesis, but their expert reports did not clearly state or substantiate that opinion. Pseudocyesis is an extremely rare disorder. As such, it is unlikely that individuals with the disorder will undergo PET scans or that scientists will be able to discern a signature PET scan pattern to diagnose the disorder. Other than his mention of the study on rats, there was no evidence offered to show the scientific reliability of Dr. Gur's opinion. Similarly, no evidence was offered that individuals suffering from other somatoform disorders have somatomotor abnormalities similar to Montgomery's. As stated above, the PET evidence that showed increased activity in the limbic and somatomotor regions of Montgomery's brain and the evidence that those areas are associated with certain functions was reliable and should have been admitted. The opinion that the abnormalities were consistent with pseudocyesis, however, did not rise to the level of scientific knowledge. A hypothesis without support, like the one posited here, is no more than a subjective belief or an exercise in speculation. [I]t thus is not knowledge, nor is it based upon sufficient facts or data or the product of reliable principles and methods applied reliably to the facts of the case. Tamraz, 620 F.3d at 670 (quoting Fed.R.Evid. 702) (internal quotations and alterations omitted). The district court thus did not abuse its discretion in excluding Dr. Gur's opinion during the guilt phase of trial. Montgomery also contends that the exclusion of Dr. Gur's opinion at the penalty phase of the trial amounted to reversible error. We review the district court's evidentiary rulings for an abuse of discretion, and we determine de novo the question of whether Montgomery's constitutional rights have been violated. Purkey, 428 F.3d at 756-57. Even if we conclude that the district court erred, we cannot reverse or vacate a federal death sentence on account of an error that is harmless beyond a reasonable doubt. Id. at 757. During the penalty phase of a capital trial, [i]nformation is admissible regardless of its admissibility under the rules governing admission of evidence at criminal trials except that information may be excluded if its probative value is outweighed by the danger of creating unfair prejudice, confusing the issues, or misleading the jury. 18 U.S.C. § 3593(c). Since the need to regulate the scope of testimony is less at the penalty phase than at the guilt phase of trial, parties may present evidence `as to any matter relevant to the sentence.' United States v. Lee, 274 F.3d 485, 494 (8th Cir.2001) (quoting 18 U.S.C. § 3593(c)); see also Williams v. New York, 337 U.S. 241, 247, 69 S.Ct. 1079, 93 L.Ed. 1337 (1949) (The factfinder at the penalty phase should not be denied an opportunity to obtain pertinent information by a requirement of rigid adherence to restrictive rules of evidence properly applicable to the trial.); Gregg v. Georgia, 428 U.S. 153, 204, 96 S.Ct. 2909, 49 L.Ed.2d 859 (1976) (At the penalty phase, it [is] desirable for the jury to have as much information before it as possible when it makes the sentencing decision.). Under the Federal Death Penalty Act's low threshold for admissibility, Dr. Gur's interpretation of the PET scan was arguably admissible. [8] Whether its exclusion constituted reversible error is another question. We conclude that any error in excluding the proposed testimony was harmless beyond a reasonable doubt. The jury heard extensive testimony from Drs. Ramachandran, Logan, and Kuncel, as well as from Montgomery's treating psychiatrist, about Montgomery's background and psychiatric diagnoses. Dr. Gur's testimony would have informed the jury that Montgomery's brain had certain functional abnormalities, would have offered his minimally probative and scientifically unreliable opinion that the abnormalities were consistent with the pseudocyesis diagnosis, and would have expressed his opinion that the brain she has may explain at least part of what happened and that the abnormalities contributed to her actions. Nevertheless, we conclude that what we said in Purkey is of equal force in this case: [A]lthough we recognize that a jury may be more likely to believe that someone suffers from a problem if its cause is explained, we nevertheless harbor no doubt that considering the minimal probative value of the evidence and the overwhelming evidence and jury findings of serious aggravating factors, its exclusion was harmless. 428 F.3d at 758.
According to Dr. Gur's report, Montgomery's MRI revealed structural abnormalities, including reduced brain volume in the right parietal lobes and right medial gray matter. Right parietal dysfunction, according to the report, manifests itself behaviorally in loss of sense of self, difficulties in emotion processing, attentional neglect and depressed or flat affect. At the Daubert hearing, the experts interpreted a graph in Dr. Gur's report that charted the deviation of Montgomery's MRI results from normal. Montgomery's parietal and medial gray matter regions were less than one standard deviation from normal. Dr. Evans explained that Montgomery's results were within the normal range and that approximately fifty percent of the population would have comparable results. Montgomery's ventrical measurements were one standard deviation from normal, and Dr. Evans stated that approximately thirty percent of the population would have similar results. Drs. Evans and Mayberg testified that Montgomery's deviations were not statistically significant because none of her measurements deviated more than one standard deviation from the mean. Dr. Mayberg also testified that to infer statistical analysis from numbers within the normal range and extrapolate about complex behavior that doesn't have a known brain organization is basically having an opinion that far exceeds both the data we have here and what is known in the literature. Dr. Gur testified that, even if the deviations were not statistically significant, they were nonetheless clinically significant. Dr. Gur compared Montgomery's right parietal and medial gray matter to her left-side counterparts. Based on his eyeball comparison, he determined that Montgomery's right parietal and medial gray matter appeared abnormally low. Dr. Evans testified, however, that Dr. Gur had failed to show that Montgomery's left-right difference was abnormal. The district court did not abuse its discretion in excluding the MRI evidence from both the guilt and the penalty phases of the trial. It found unreliable the methodology underlying Dr. Gur's opinion that the results were clinically significant. Moreover, it found that the MRI results had no scientifically recognized significance. Accordingly, the district court concluded that the results were irrelevant to Montgomery's insanity defense and the mitigating factors she pleaded. The district court thus exercised its authority to exclude, as irrelevant, evidence not bearing on the defendant's character, prior record, or the circumstances of [her] offense. Lockett v. Ohio, 438 U.S. 586, 604 n. 12, 98 S.Ct. 2954, 57 L.Ed.2d 973 (1978) (plurality opinion).