At the link here, we have a link to something called the Reference Manual on Scientific Evidence, a document designed to guide judges in the United States who are evaluating claims of scientific evidence. The page gives this description of that manual:
"A joint product of the Federal Judicial Center and the National Academies of Sciences, Engineering, and Medicine, the Reference Manual on Scientific Evidence, Fourth Edition supports judges in managing cases involving complex scientific and technical evidence by describing the basic tenets of key scientific fields and by providing examples of cases in which that evidence has been used. It is intended to assist judges in identifying issues commonly in dispute and to help judges reach an informed and reasoned assessment of those issues based on expert evidence that is faithful to the law and within the boundaries of scientifically sound knowledge."
Alarm bells should go off when we read that phrase "the basic tenets of key scientific fields." Tenets refers to beliefs, not facts. The Merriam Webster dictionary defines a tenet as "a principle, belief, or doctrine generally held to be true especially : one held in common by members of an organization, movement, profession, etc."
In Volume II of the Reference Manual on Scientific Evidence, Fourth Edition (which you can read using the link here) we have on page 1185 a chapter on neuroscience, one entitled "Reference Guide on Neuroscience." We get this description of the two authors:
Henry T. Greely, J.D., is the Deane F. and Kate Edelman Johnson Professor of Law; Professor, by
courtesy, of Genetics; and the Director of Center for Law and the Biosciences, at Stanford University.
Nita A. Farahany, J.D., Ph.D., is the Robinson O. Everett Professor of Law and Philosophy and
Founding Director for the Initiative for Science and Society at Duke University
We have a chapter that is being used to guide the decisions of United States judges when evaluating attempts to introduce neuroscience as evidence; but neither of the authors of the chapter is a neuroscientist (judging from the statements above and online statements of their educational backgrounds, and defining a neuroscientist as someone with a PhD or Master's Degree in neuroscience). The authors make some serious errors in their chapter, and I guess we should not be surprised given their lack of deep expertise in neuroscience. One of the authors (Henry T. Greely) is the author of a book with the very strange title "The End of Sex and the Future of Human Reproduction."
Greely and Farahany start out with groundless bombast by claiming "science’s understanding of the human brain is increasing exponentially" and that "we
know almost infinitely more than we did thirty years ago." To the contrary, there has been little real important progress in neuroscience in the past 30 years. Thirty years ago we knew the basic facts about the brain that we now know. There has been no real progress in proving the main claims that neuroscientists like to make about brains, such as the claim that the brain is the source of the human mind and the storage place of memories. Although there has been lots of use of fancy new technologies, this has not led to any great discovery during the past 30 years. Neuroscientists are still basically where they were 30 years ago, without any real understanding of how a brain could produce thought, self-hood, imagination, learning, recall or the lifelong preservation of memories. The microscopic examination of brain tissue has still failed to discover any trace in brain tissue of anything a human has learned.
In the next paragraph Greely and Farahany say something that contradicts their previous boasts. They confess, "We still remain very far from a deep and broad understanding of how human brains work." But then they make this untrue statement: "If, as neuroscience indicates, our mental states correspond to,
and result from, physical states of our brain, our increased ability to discern
those physical states will have huge implications for the law." Neuroscience does not actually indicate that "our mental states correspond to, and result from, physical states of our brain," although such a belief is widely held in the belief community of neuroscientists. The facts of neuroscience, psychology and medical science again and again contradict the claim that "our mental states correspond to, and result from, physical states of our brain." Among those facts are the following:
- It is a fact that there are many dramatic cases in the medical literature of people who had more or less normal minds even though large fractions of their brain (or most of their brains) were destroyed due to injury or disease, including super-dramatic cases of people with good minds but less than 15 percent of their brains.
There is no understanding of how brains could achieve the instantaneous relevant recall of distant, obscure memories that humans routinely show, when someone is asked a trivia question, given the lack of any coordinate system or addressing or indexing in a brain that might allow some exact position of a stored memory to be very quickly found. There is no understanding whatsoever of how concepts, visual information, long series of words, and episodic memories could ever be physically stored by a brain in any way that would translate all these diverse types of information into synapse states or neuron states. It is a fact that old humans can reliably remember experiences they had more than 50 years ago, an ability that should be impossible given the very rapid molecular turnover and structural turnover in synapses (which neuroscientists typically claim to be the storage place of memory), and given that the proteins that make up such synapses have short average lifetimes of only a few weeks, 1000 times shorter than the length of time humans can remember things. The 2018 study here precisely measured the lifetimes of more than 3000 brain proteins from all over the brain, and found not a single one with a lifetime of more than 75 days (figure 2 shows the average protein lifetime was only 11 days). It is a fact that the microscopic examination of very many thousands of brains of recently deceased people (and the microscopic examination of endless samples of brain tissue extracted from living people) has never produced the slightest trace of learned information, something that would have been discovered in brains 50 years ago if brains stored memories and brains are the source of the human mind.
It is a fact that for more than 50 years numerous people have reported vivid near-death experiences and out-of-body experiences occurring after their hearts stopped and their brains were inactive, during times when their brains had flatlined, and they should have had no consciousness at all (under "brains make minds" assumptions), with many of the observation details they reported seeing during such brain-inexplicable should-have-been-utterly-unconscious experiences being independently verified (as described here).
After some preliminary rhetoric, Greely and Farahany start getting into details. They give us a long discussion of the features and anatomy of the brain, one that is pretty factual and unobjectionable. But on page 1199 they start repeating "old wives' tales" of neuroscience literature. They state that the amygdala "modulates learning and memory." The claim is not well-established, and "modulates" is a rather vague word. More specifically, the authors dogmatically claim that "memories appear to be
stored over much of the cortex." There is no scientific basis for this claim, and the use of the phrase "appear to be" indicates that the authors lack a firm scientific basis. Very much tissue from all parts of the brain has been microscopically examined, including tissue from recently deceased people, and tissue extracted from living people as part of surgical operations. Such microscopic examination has never revealed the slightest trace of anything a human has learned or experienced.
Some surgical operations serve as a test for the claim that memories are stored in the brain. For example, to treat very bad seizures, doctors sometimes remove half of the brain in a radical operation called a hemispherectomy operation. We have quite a few cases of people who had such operations without reporting a loss of memories, and without seeming to suffer a loss of memories. Such cases directly contradict Greely and Farahany's claim that "memories appear to be stored over much of the cortex," and also contradict all claims that memories are stored in the brain. You can read about such cases in my post "Preservation of Mind and Memories After Removal of Half a Brain" here.
Below are some results reported in the American Journal of Psychology, Vol. 46, No. 3 (Jul., 1934), pages 500-503, regarding work of W. E. Dandy, in which he removed half of the brains of patients. You can read the results in the preview here (without doing any registration). We read the following (I have put a few of the sentences in boldface):
“Dandy has completely removed the right cerebral hemisphere from eight patients. He has performed total extirpations of one or more lobes much oftener... There are tabulated below certain generalizations on the effects of removing the right hemisphere.... The operation was the complete extirpation of the right frontal, temporal, parietal, and occipital lobes peripheral to the corpus striatum. The weight of the tissue removed varies, with the pathological conditions involved, from 250 to 584 grm [grams].Coherent conversation began within twenty-four hours after operation, and in one case on the afternoon of the same day. Later examinations showed no observable mental changes. The patients were perfectly oriented in respect of time, place, and person; their memory was unimpaired for immediate and remote events; conversation was always coherent; ability to read, write, compute, and learn new material was unaltered. Current events were followed with normal interest. There were no personality changes apparent; the patients were emotionally stable, without fears, delusions, hallucinations, expansive ideas or obsessions, and with a good sense of humor; they joked frequently. They showed a natural interest in their condition and future. They cooperated intelligently at all times throughout post-operative care and subsequent testing of function.”
It would be rather hard to imagine a more decisive refutation of the claim that the human brain is the source of the human mind, and the claim that the human brain is the storage place of human memories.
In the scientific paper here, we have on page 248 and page 250 before and after test scores for various subjects who had of their brains removed in hemispherectomy operations. The IQ score differences are slight. IQ tests don't involve learned information, but almost any IQ test would be largely a test of memory, as it would be a largely a test of ability to read test questions. On the same pages we have before and after test scores for Peabody Picture Vocabulary Tests given to various subjects who had half of their brains removed in hemispherectomy operations. In these tests, someone is shown picture cards like the one below, and asked to name the words represented by the pictures. These tests are tests of memory retention after removal of half of the brain. On these memory tests there was no decline in the score of 21 subjects mentioned on page 248, and no decline in 7 subjects mentioned on page 250.
An article in the LA Times tells us about memory preservation in a young girl who lost half her brain: “How is it that 8-year-old Beth Usher of Storrs, Conn., can lose her left hemisphere, yet retain her large repertoire of knock-knock jokes? Beth’s memories survived not just the loss of brain tissue, but also the 32 days that she spent in a coma, the result of some brain stem swelling that occurred in response to the trauma of surgery. Shortly after Beth regained consciousness, her father began quizzing her about people and places from her past. Brian Usher didn’t get very far. 'Dad,' Beth interrupted, with a trace of impatience. 'I remember everything.' ”
In a scientific paper ("Why Would You Remove Half a Brain? The Outcome of 58 Children After Hemispherectomy −−The Johns Hopkins Experience: 1968 to 1996") we read about how surgeons at Johns Hopkins Medical School performed fifty-eight hemispherectomy operations on children over a thirty-year period. Eleven of these children had the left hemisphere of their brains removed; most of the rest had the right hemisphere of their brains removed. The paper states this:
"Despite removal of one hemisphere [i.e. one half of the brain], the intellect of all but one of the children seems either unchanged or improved....Although there have been major concerns about loss of language after left hemispherectomy, all eleven of these children have regained virtually normal language....It is tempting to speculate, that the continuous electrical activity of these severely dysfunctional hemispheres interferes with the function of the other, more normal hemisphere. This might explain why motor function improves after hemispherectomy and why language recovers after removal of the dysfunctional left hemisphere, but does not seem to fully transfer before surgery. Perhaps it also partially explains intellectual improvement in these children after removal of half of the cortex. We are awed by the apparent retention of memory after removal of half of the brain, either half, and by the retention of the child’s personality and sense of humor."
The observational results quoted above collectively defy Greely and Farahany's claim that "memories appear to be stored over much of the cortex," and they also dramatically discredit Greely and Farahany's attempt to persuade us that "our mental states correspond to, and result from, physical states of our brain."
On the same page 1199 Greely and Farahany incorrectly state that "the hippocampus is necessary for the creation of many kinds of memory." This claim is debunked in my widely read post "Studies Debunk Hippocampus Memory Myths," which you can read here. On page 1216 the authors try to back up that claim about the hippocampus, offering this widely repeated but untrue claim:
"Our understanding of the role of the hippocampus in creating memories, as one example, was greatly aided by study of a patient known as H.M. When he was twenty-seven years old, H.M. was treated for intractable epilepsy, undergoing an experimental procedure that surgically removed his left and right medial temporal
lobes, including most of his two hippocampi. The surgery was successful, but from that time until his death in 2008, H.M. could not form new long-term memories, either of events or of facts."
The claim is untrue, and at the beginning of my post "Studies Debunk Hippocampus Memory Myths," which you can read here, I cite quite a few examples of this person (H.M.) learning new things after his operation. For example, a 14-year follow-up study of patient H.M. (whose memory problems started in 1953) actually tells us that H.M. was able to form some new memories after his operation. The study says this on page 217:
"In February 1968, when shown the head on a Kennedy half-dollar, he said, correctly, that the person portrayed on the coin was President Kennedy. When asked him whether President Kennedy was dead or alive, and he answered, without hesitation, that Kennedy had been assassinated...In a similar way, he recalled various other public events, such as the death of Pope John (soon after the event), and recognized the name of one of the astronauts, but his performance in these respects was quite variable."
In the same post ("Studies Debunk Hippocampus Memory Myths," which you can read here) I cite a great deal of evidence refuting the claim of Greely and Farahany that " the hippocampus is necessary for the creation of many kinds of memory." For example, A 2020 paper is entitled "Preserved visual memory and relational cognition performance in monkeys with selective hippocampal lesions." The paper states this:
"We tested rhesus monkeys on a battery of cognitive tasks including transitive inference, temporal order memory, shape recall, source memory, and image recognition. Contrary to predictions, we observed no robust impairments in memory or relational cognition either within- or between-groups following hippocampal damage."
Citing a previous study, the paper notes that "formation of new memories in the object-in-scene task, one of the most accepted tests of episodic memory used with nonhuman primates, was found to be unaffected by lesions of the hippocampus itself." It also notes that "There is a concerning lack of clear causal evidence for a critical role of the hippocampus in visual memory, episodic memory, recollection, or relational cognition in nonhuman primates."
After some pages discussing various neuroscience techniques and technologies, Greely and Farahany finally make a claim of relevance to neuroscience and the law. They state on page 1221, "More than fifteen different laboratories have collectively published twenty to thirty peer-reviewed articles finding some statistically significant relationship between fMRI-measured brain activity and deception." This means very little, because the use of way-too-small study group sizes is an epidemic in today's neuroscience.
On page 1231 the authors confess this:
"There are now about twenty to thirty peer reviewed publications that, using fMRI, find statistically significant differences
in patterns of brain activation depending on whether the participants were telling the truth or (typically) telling a lie when instructed to do so. Many of those
publications find patterns that are different from, and often inconsistent with, the
patterns described in the other publications. Multiple inconsistent publications do
not add weight to a scientific method or theory; indeed, they may subtract from it."
The authors make a good point on page 1233 (regarding introducing neuroscience evidence into a court case):
"The time
necessary to introduce such evidence, and to educate the jury (and judge) about
it, will usually be extensive. The possibilities for confusion are likely to be great.
And there is at least some evidence that jurors (or, to be precise, 'mock jurors')
are particularly likely to overestimate the power of neuroscience evidence.37
A high-tech 'picture' of a living brain, complete with brain regions shown in
bright orange and deep purple (colors not seen in an actual brain), may have an
unjustified appeal to a jury. In each case, judges will need to weigh possibilities
of confusion or prejudice, along with the near certainty of lengthy testimony,
against the claimed probative value of the evidence."
On page 1246 Greely and Farahany talk about "retail" use of neuroscience in court cases, and make a bullet list of what they call "the most plausible categories for such retail uses." They include on their bullet list these items:
- "predicting future behavior for sentencing"
- "credibility or deception in current statements"
- "the existence or nonexistence of a memory of some event and, possibly,
some information about the status of that memory (true, false; new, old,
etc.)"
- "the presence of bias against a party"
The authors mislead us by claiming that such things are "plausible categories" for the use of neuroscience in court cases. Neuroscience can do nothing to predict future crimes; neuroscience can do nothing to tell us about credibility of deception in current statements; neuroscience can do nothing to determine "the existence or nonexistence of a memory of some event"; and neuroscience can do nothing to detect "the presence of bias against a party." If any reliable scientific testimony were offered along such lines, it would fall under the category of psychology rather than neuroscience.
Talking about efforts to use brain scans to detect lies (an area that is a morass of junk science), the authors start out well, but then goof at the end, saying this:
"Currently, as far as we know, evidence from fMRI-based lie detection has not
been admitted into evidence in any court, but it was offered—and rejected—in
at least three cases, United States v. Semrau,
99 Wilson v. Corestaff Services L.P.,
100
and a widely publicized murder trial, Maryland v. Smith,
101 in the early 2010s. Since then, efforts to introduce evidence from this technology have largely
disappeared—we find no reported cases about such attempted uses since 2012—
but the story of its rise and fall provides a good example of a path for new neuroscience evidence. And the underlying science still exists and could well end up
in court again."
The underlying science still exists? No, it does not. Greely and Farahany actually make it rather clear in the following pages that there is no solid scientific basis for thinking that fMRI machines can detect lying.
All in all, Greely and Farahany's chapter is not one I can condemn as something that should be trashed and completely replaced by the writing of some other writer or writers. Their chapter is mostly fairly good work, and it deals fairly well with the limitations and weaknesses of today's neuroscience (although not discussing that half as well as it should do to properly advise judges dealing with attempts to introduce neuroscientist work as evidence). But their chapter has some serious errors, and some utterly unnecessary affirmations of groundless neuroscientist dogmas. The chapter could be fixed with a few days' work. I would suggest taking out the false and dubious statements, and adding ten additional paragraphs warning judges of the low standards, bungling methods and very frequent errors in today's cognitive neuroscience, along with the frequent spreading in that field of groundless triumphal boasts. Then add ten other long paragraphs discussing all of the reasons for doubting the dogmas of today's neuroscientists, which are additional reasons why judges should be extremely careful about allowing the introduction of neuroscience evidence in court cases.
The job of properly advising people about the weighty question of whether the brain produces the mind and whether memories are stored in the brain is one requiring years of the deepest study of very many topics including neuroscience, psychology, parapsychology and relevant medical case histories and case histories of exceptional human mental performances. When people whose background is mainly in the law and legal matters offer their opinion on that question, we need not necessarily assume that they have adequately studied the relevant evidence, unless we have evidence of such scholarship.
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