Sunday, September 6, 2020

In Neuroscience Papers Bluffing Is More Common Than Candor

The Cornell Physics Paper Server at arxiv.org is mainly useful for finding papers on physics, but it also includes many papers on quantitative biology and computer science. Below are some observations I made after searching for papers with "memory" or "thought" in the title.

Occasionally a neuroscience paper will have a little candor regarding the vast gulf between the claims neuroscientists make and the low-level data they observe. One paper gives us some indications that what neuroscientists observe on a low level is something totally different from the stability we see in long-term memories.  We read the following, in which "turn over" refers to demise and replacement:

"The building blocks of the brain are in constant flux at the subcellular, cellular and circuit level. Synaptic and non-synaptic proteins are mobile [] and rapidly turn over on the scale of hours to days []. Individual synapses continuously change their size and strength both in vitro and in vivo []. Most notably, however, the mature brain appears to continuously rewire itself, even without experimental intervention [,]. This is evident from the perpetual turnover of dendritic spines, small protrusions from the parent dendrites of most cortical neurons that are commonly used as proxies for excitatory synapses. Depending on the cell types and brain regions investigated, dendritic spines are gained and lost at rates ranging from approximately 1% per day in primary visual cortex [] over approximately 5% per day in the CA1 region of hippocampus [] to up to approximately 15% per day in primary somatosensory cortex [] (but see [,,] for potential pitfalls of these quantifications)." 

Another paper refers to it as a "fundamental enigma" that memories can last for even weeks (which is not surprising, given the facts above). Using the acronym LTM for long-term memory, the paper says, "A fundamental enigma is how the physical substrate for storage of LTM can nonetheless be preserved for weeks, months, or a lifetime.
"

The paper here suggests that there is no understanding of how a brain could ever translate episodic experience or learned knowledge into neural states. The paper errs only in using the term "largely" when it should have used the word "totally." We read this:

"Codifying memories is one of the fundamental problems of modern Neuroscience. The functional mechanisms behind this phenomenon remain largely unknown."

The paper "Long Term Memory: Scaling of Information to Brain Size" by Donald R. Forsdyke is a paper of unusual candor.  We read the following about patients whose brain regions consisted almost entirely of watery fluid rather than neurons:

"The journal Science, under the title 'Is your brain really necessary?' (Lewin 1980), described a series of 600 cases with residual ventricular enlargement that had been studied in Britain by paediatrician John Lorber (1915-1996). Again, while long-term memories were not directly assessed, intelligence quotients (IQs) were. Amazingly, in 60 of Lorber’s cases, ventricular fluid still occupied 95% of cranial capacity. Yet half of this group had IQs above average. Among these was a student with an IQ of 126 who had a first class honours degree in mathematics and was socially normal....The drastic reduction in brain mass in certain, clinically-normal, hydrocephalic cases, seems to demand unimaginable levels of redundancy and/or plasticity – superplasticity. How much brain must be absent before we abandon these explanations and look elsewhere?...Regarding the human brain’s 'massive storage capacity' for object details, Brady et al. (2008) have also challenged 'neural models of memory storage and retrieval.' ...The unconventional alternatives are that the repository is external to the nervous system, either elsewhere within the body, or extra-corporeal. The former is unlikely since the functions of other body organs are well understood. Remarkably, the latter has been on the table since at least the time of Avicenna and hypothetical mechanisms have been advanced (Talbot 1991; Berkovich 1993; Forsdyke 2009; Doerfler 2010). Its modern metaphor is 'cloud computing.' ” 

But such candor and willingness to challenge fossilized dogmas is rare. What is more common is for neuroscience papers to give us bluffing, in which an author pretends to have something he doesn't have, like a poker player with a weak hand acting as if he has a royal flush.  An example is the paper "Neural origins of self-generated thought: Insights from intracranial electrical stimulation and recordings in humans."  The paper would have us believe that it is presenting some evidence that brains produce thinking.

But when we look at the visuals, we see no substantial evidence for such a thing.  Figure 1 and Figure 2 gives us the usual deal in which some tiny difference in signal strength is shown in a very bright color such as bright red or bright blue.  But in Figure 3 we get some hard numbers. We have some graphs showing brain signal differences during thinking, and we can see from the visuals that the percent signal change was never more than a tenth of one percent, never more than 1 part in 1000.   Of course, such a tiny difference in signal strength is no robust evidence at all that brains are producing thought, but is merely the kind of difference we would expect from chance variations.

A recent example of a bluffing neuroscience paper is the 21-page paper "Memory Systems of the Brain," which seems to be bluffing us in the sense that it provides no compelling evidence for such systems.  We have no discussion of how a brain could translate learned knowledge or experiences into neural states or synapse states. We have no discussion of how a brain could store a memory for decades, or even for a single year. We have no discussion of how a brain could retrieve a memory. 

How does the paper manage to fill up 21 pages without any such things? The paper follows various space-filling strategies used by similar papers:

(1) An historical approach is taken in which pages are filled up with a discussion of the history of human thinking about memory. 
(2) Lots of space is used up with a discussion of different types of memory. For example, there is a discussion about the difference between short-term memory, working memory and long-term memory. 
(3) There is a discussion of a handful of cherry-picked case histories, carefully chosen to make us believe in neuroscientist dogmas about a brain storage of memories. 

There are innumerable case histories that could be quoted, but neuroscientists tend to spend excessive time citing the cases of patient H.M and patient K. C.  The author of the "Memory Systems of the Brain" paper repeats the incorrect claim so often made about patient H.M, a claim that he was unable to form new memories. The paper states that patient H.M. "became unable to consciously recollect new events in his life or new facts about the world."  This is not entirely correct. 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. 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."

Patient K.C. was a patient who had extensive brain damage in a motorcycle accident, but could still remember learned information well. However, he was unable to provide autobiographical recollections of events before his injury.  But a study of a patient with a similar problem  (patient Y.K.) suggests the possibility that memory of experiences was not lost, but merely the ability to recall such information in the form of a first-person narrative. In one source we read the following:

"For example, one patient (Y.K.) was reported to have some knowledge of remote incidents in his life but was unable to 'remember' them (). Using the Remember and Know procedure (), Y.K. assigned K responses to all of his remote recollections, indicating that he had knowledge of the events as facts but could not actually place himself mentally at the scenes where the events occurred."

The "Memory Systems of the Brain" paper seems to hint that there is no understanding of how a brain could store a memory, when it states this: "It remains unclear how neuronal cooperativity in intact networks relates to memories or how network activity in the behaving animal brings about synaptic modification "  Before stating that, the paper makes this claim: "Clinical evidence indicates that damage to the hippocampus produces anterograde amnesia."  But while there are a few famous cases of patients with impaired recall of past experiences after hippocampus damage, there are vastly more cases of people who could recall previous memories fairly well after the total removal of the hippocampus. 

The "Memory Systems of the Brain" paper conveniently fails to mention the main research paper on the hippocampus and memory: the paper "Memory Outcome after Selective Amygdalohippocampectomy: A Study in 140 Patients with Temporal Lobe Epilepsy." That paper gives memory scores for 140 patients who almost all had the hippocampus removed to stop seizures.  Using the term "en bloc" which means "in its entirety" and the term "resected" which means "cut out," the paper states, "The hippocampus and the parahippocampal gyrus were usually resected en bloc."  The paper refers us to another paper  describing the surgeries, and that paper tells us that hippocampectomy (surgical removal of the hippocampus) was performed in almost all of the patients. 

The "Memory Outcome after Selective Amygdalohippocampectomy" paper does not use the word "amnesia" to describe the results. That paper gives memory scores that merely show only a modest decline in memory performance.  The paper states, "Nonverbal memory performance is slightly impaired preoperatively in both groups, with no apparent worsening attributable to surgery."  In fact, Table 3 of the paper informs us that a lack of any significant change in memory performance after removal of the hippocampus was far more common than a decline in memory performance, and that a substantial number of the patients improved their memory performance after their hippocampus was removed. 

In light of these results, it is objectionable for the "Memory Systems of the Brain" paper to have made this claim:  "Clinical evidence indicates that damage to the hippocampus produces anterograde amnesia."  The paper should merely have stated that there are a small number of famous cases of patients who had both hippocampus damage and anterograde amnesia, but that removal of the hippocampus generally does not produce either anterograde amnesia or even a very severe decline in memory performance. 

We should remember that nothing is proven by a few cases in which a small number of people had some brain damage and also a memory problem. We do not know in such cases whether there is a causal relation between the brain damage and the memory problem. If I scanned enough data in hospital records, I could surely find cases in which someone had a toothache before dying suddenly. But that would not at all prove that toothaches can produce sudden death. 

The "Memory Systems of the Brain" paper presents no good evidence that memories are stored in particular parts of the brain. But it does make this claim that it completely fails to back up with any evidence: "Memories are stored in the brain in a distributed pattern in the outer layer of the cortex, related to the area of the brain that initially processed them."  At the end of this statement, the paper makes a reference to another neuroscience paper, as if such a thing had been established by that paper.  The paper is the paper "Declarative and Nondeclarative Memory: Multiple Brain Systems Supporting Learning and Memory" by Larry R. Squire.  That paper fails to state any such claim that memories are stored in the outer layer of the cortex, and does not at all provide any substantial evidence to back up such a claim. 

The "Memory Systems of the Brain" paper does cite another paper co-authored by Squire, the paper "Structure and function of declarative and nondeclarative memory system." When I examine the paper in question, I find it does not actually make the claim that memories are stored in the outer layer of the cortex, and merely weakly says that the neocortex "is believed to be the permanent repository of memory."  The paper in question  does not establish any claim about a storage place of memory, and  merely mentions some small-effect experiments with monkeys that had damage to various regions of their cortex. None of the monkeys had any more than a small deficit in their memory performance after such damage.  For example, we are told in one case of cortical damage, performance declined from 79% correct to 67% correct, and in another such case  performance declined from 79% correct to 77% correct; and it is noted that cortex-damaged monkeys  "were unimpaired at learning and retaining single-object discriminations."  It is not very unlikely that you might get such results purely because of chance variations, particularly if you were using a small sample size less than 15. 

In this paper "Structure and function of declarative and nondeclarative memory systems" we learn that the authors are relying on absurdly underpowered cortex memory studies. For example, Figure 8 refers us to an experiment using only 5 monkeys with cortex lesions, which is way too few for a reliable experimental result. The minimum for a moderately reliable result is 15 subjects per study group.  


Below are some other examples of weak elements in the "Memory Systems of the Brain" paper:

(1) We are told on page 15 that neuroimaging shows that certain regions of the brain show "common activity" when memories are formed. This is irrelevant, because all regions of the brain are active during normal consciousness.
(2) We are told on page 18 that a paper showed "increased activity in the amygdala" for those who learned better. The paper in question actually only showed that those with higher levels of stress hormones in the amygdala tended to remember more.  But that does nothing to show that the amygdala stores memories, but merely shows we remember better when emotionally aroused. You could do a similar test showing that people remember more what they experience when their heart rate is 130 beats per minute rather than a normal rate of only 65 beats per minute.  But that would do nothing to show that memories are stored in the heart. 
(3) On page 14 we are told, "Imaging studies have also illuminated the contributions of distinct prefrontal regions to encoding and retrieval."  At the end of this statement there is a reference to three papers. The first of these papers used only 6 subjects per experiment, way too small a sample size to be a reliable result (15 subjects per study group has been suggested as a minimum for reliable results, and Kelly Zalocusky PhD hints that 31 subjects per study group may be needed). The second of these papers suffered from the defect of judging strength of memory based on subjective "confidence levels" rather than objective accuracy, and also the very large defect of failing to specify how many subjects were used for the experiments (we are told 14 subjects gave their permission to be tested, but not told how many subjects actually participated; and the graphs suggest that maybe only half that many participated). The third of the papers presents no original research. 

Containing some very dubious assertions, some references to weak research and some troubling omissions (such as no mention of the supremely relevant research of John Lorber or the short lifetimes of synapse proteins), the paper "Memory Systems of the Brain" is an example of a bluffing neuroscience paper (in the sense that its title suggests something the paper does not deliver). The author does nothing to describe a system of the brain capable of encoding memories. He does nothing to describe a system in the brain capable of storing memory information. He does nothing to describe in the brain a system capable of preserving memory information for decades. He does nothing to describe a system in the brain capable of retrieving memories. So he does not describe any such thing as a memory system in the brain.  Nature never told us that brains store memories; it was merely neuroscientists who told us that, without any good evidence for such a claim. 

Friday, August 21, 2020

Young Age of Languages Contradicts Claims of Neural Storage of Linguistic Information

The term “memory” refers to an extremely large set of faculties of the human mind, including all of the following:

Linguistic retrieval: the ability to recall particular stretches of words that have been memorized, and the ability to very rapidly use words you have been learned. The vast human ability for linguistic recall is shown by stage actors who memorize very large roles such as the role of Hamlet. An even greater capacity for recall is shown by Muslims who memorize every word of their holy book. Humans can also use words at dizzying speeds, which may involve people speaking at a clip of more than 2 words per second.

Literary passage recognition: the ability to identify particular literary passages when they are recited. Biblical scholars often show great capacity in this regard, and can often identify the correct biblical book (and often the exact chapter and verse number) when any of thousands of scriptural quotes are recited.

Word recognition: Humans have an immense ability to recognize words very rapidly. We see this going on whenever anyone understands someone talking very rapidly. English speakers with a good vocabulary can instantly recognize and understand more than 50,000 words.

Visual retrieval: the ability to recall in great detail particular visual experiences a person had. Legal testimony shows that humans have a very high capacity in this regard, although accuracy is probably less than for memorized literary information. Court witnesses will often give very lengthy testimony mentioning dozens of visual details of things they saw.

Visual recognition: the ability to identify a place, object or face when someone sees it. Human ability in this regard is very high. The average person can probably recognize 5000 or more objects and 5000 or more faces, even when seeing objects with large amounts of variations. For example, you can not only recognize a single photo of the latest US president, but can also recognize a hundred different photos of such a person, each with its own variations. Visual recognition occurs with blazing speed, often taking less than a fraction of a second. A person may take less than a second to start running away from an animal recognized as a danger, such as a wolf, bear or snake.

Musical retrieval: Humans have extremely impressive capacities for musical retrieval. Such abilities are shown by people such as pianists who can play hundreds of songs from memory, and opera singers who can sing all the notes of very long Wagnerian musical roles such as Tristan, Siegfried or Hans Sachs.

Musical recognition: Humans have an astonishing ability to recognize pieces of music, even when they are performed with variations. We saw this ability on television in the popular TV show Name That Tune.

Fast musical memorization: This very rare ability is shown by some musical savants who have the ability to memorize any piece of music they hear a single time.


There is not a single one of these capabilities that can be explained as products of the human brain. We know of no neural faculties that can explain instant visual recognition.  There is no convincing evidence that any part of the brain works harder during visual recognition than during visual non-recognition. A scientific paper tells us, "Specific complex mental processes cannot be inferred directly from functional brain imaging data." 

The study here is an example of a brain scan study failing to provide evidence that the brain produces visual recognition.  The study has the inappropriate title "Successful Decoding of Famous Faces in the Fusiform Face Area," an idea that is not at all shown by the paper. The paper describes a brain scan study in which 17 people had their brains scanned while looking at famous faces that should have provoked recognition. According to Figure 3, 11 out of 12 brain regions checked showed a 1% or less percent signal change during facial recognition, not more impressive than we would expect to have by chance. A single tiny brain region (called Right FFA) showed a 2% percent signal change, when tested with faces of 2 Israeli prime ministers.  But in a replication experiment using the famous faces of Brad Pitt and Leonardo DiCaprio, this result did not hold up, with the percent signal change being no greater than 1% for any brain region.  The paper does not give any test comparing recognition versus non-recognition.  All in all, this is no compelling evidence that something from a brain is retrieved when people recognize a face. Another paper also gets a result of only about 1% percent signal change when testing face recognition in different brain areas, getting only about a 1% signal difference for this FFA region.  Two other papers (this paper  and this paper) also find less than a 1% signal difference in this FFA region when testing facial recognition.  Another paper finds only a half of 1% signal change in the FFA during face recognition. Another paper using a larger sample size of 26 people reports a signal change of much less than 1% (only a small fraction of one percent) when testing this FFA region with face recognition. 

Such tiny percent signal changes do nothing to establish any reading of information from brains when visual recognition occurs. For one thing, since the sample sizes are mostly small (around 15 people per study), you could easily get a 1% or 2% signal variation by chance (just as you can easily get 55% of your coin flips being "heads" if you only flip 20 or 40 times).  If there is some tiny little signal change in one region of the brain when a face is recognized, that might be something that has nothing to do with reading memory information from brains. For example, it might be a little of an alert effect or an "aha" emotional boost effect caused by the mere fact of a successful recognition. 

But at least someone might argue that there was lots of time for a visual recognition capability to have evolved in a brain, and that if humans have some neural capability for fast visual recognition, such a capability might have very gradually evolved over hundreds of thousands of years, or millions of years. Such a person might argue that there was a big reason why such a capability was vital for survival.  It is at least true that a species will be much more likely to survive if organisms of that species can recognize their own offspring, and instantly recognize another animal as a dangerous threat. 

But in the case of language and musical memory capabilities, we have a totally different situation.  There is no survival-of-the-fittest reason why any organism would have either impressive language memory capabilities or impressive musical memory capabilities. Neither language nor music is needed for an organism to survive in the wild.  

There is a very big reason for disbelieving in a neural storage of linguistic information. The reason is that all of the languages used by humans are relatively recent inventions.  Languages such as the English language that I speak are less than a thousand years old.  There would have been no time for humans to have evolved some language storage capability for a language that has existed for such a relatively short time. 

In ancient times people spoke languages such as Latin and Greek. You can see that the English language is less than a thousand years old by looking at the text of the early English poem Beowolf, which dates from about 700 to 1000 AD.  Below are its opening lines (you can read the full text here):

Hwæt. We Gardena in geardagum,
þeodcyninga, þrym gefrunon,
hu ða æþelingas ellen fremedon.
Oft Scyld Scefing sceaþena þreatum,
monegum mægþum, meodosetla ofteah,
egsode eorlas. Syððan ærest wearð
feasceaft funden, he þæs frofre gebad,
weox under wolcnum, weorðmyndum þah,
oðþæt him æghwylc þara ymbsittendra
ofer hronrade hyran scolde,
gomban gyldan. þæt wæs god cyning.

It is clear from this that the English language as it is now spoken has existed for less than a thousand years.  How could the brain have some elaborate system that allows Hamlet actors to store all the lines of very long English language roles such as Hamlet, when the English language has not existed for more than a thousand years? This seems impossible. 

Could it be that through some miracle of rapid evolution that the human brain has acquired some great neural capability that it did not have a thousand years ago, allowing it to store lots of data from a relatively recent language such as English? All claims of rapid new function evolution are mathematically unbelievable, and there is no evidence of any such rapid change in the human brain or the human genome.  The article here at a major science journal is entitled "Scientists track last 2000 years of British evolution." All that is mentioned is a few minor things such as greater lactose tolerance.  There is no mention of any brain evolution.  It seems that 2000 years ago people had the same brains they have now. There is no evidence that the brain has undergone any change after the birth of Jesus that might allow an ability to massively store (and instantly retrieve) words in a language that is less than a thousand years old.  An article in Scientific American states, "The past 10,000 years of human existence actually shrank our brains."

A similar situation exists in regard to music. Musical notation is a relatively recent invention, an invention so recent that no melodies survive from before the time of Jesus. But Wagnerian tenors are able to memorize not just songs but musical roles that involve hours of very specific singing.  No one can explain how a brain could have acquired such a vast ability in storing and retrieving musical notes given that musical notation is such a relatively recent invention, and given that musical rememberance is a superfluous skill having nothing to do with human survival. 

Monday, August 3, 2020

Study Finds Equal Brain Connectivity in All Mammals

Observational realities frequently conflict with attempts to correlate brain size and intelligence. In a scientific paper a scientist states, "After correcting for body height or body surface area, men's brains are about 100 g heavier than female brains in both racial groups."  After adjusting for size, male brains are 7% larger, but there is not even a 3% difference in intelligence between males and females. Elephants have brains several times larger than human brains,  but elephants are not as intelligent as  humans. Removing half of a human brain in a hemispherectomy operation has no major effect on intelligence, as discussed in the posts here.  Crows have high intelligence despite tiny brains, and a lack of a neocortex. 

Sometimes it is argued that the real measure of cognitive ability is brain connectivity (the degree to which brain cells are connected with each other).  It has been suggested that maybe humans are smarter than other mammals because our neurons are better connected. But a new study indicates that the brains of humans are not better connected than the btains of other animals. The study is announced on the Science Daily web site with this headline: "MRI scans of the brains of 130 mammals, including humans, indicate equal connectivity."

We read the following:

"Researchers at Tel Aviv University, led by Prof. Yaniv Assaf of the School of Neurobiology, Biochemistry and Biophysics and the Sagol School of Neuroscience and Prof. Yossi Yovel of the School of Zoology, the Sagol School of Neuroscience, and the Steinhardt Museum of Natural History, conducted a first-of-its-kind study designed to investigate brain connectivity in 130 mammalian species. The intriguing results, contradicting widespread conjectures, revealed that brain connectivity levels are equal in all mammals, including humans." 

A Professor Assaf is quoted as stating, ""Many scientists have assumed that connectivity in the human brain is significantly higher compared to other animals, as a possible explanation for the superior functioning of the 'human animal.'" But it turns out that this assumption (a natural one from the idea that your brain is the source of your mind) just isn't true. 

So we have the brain connectivity of mice, the brain connectivity of cows, the brain connectivity of sheep. This is another reason for believing that the human mind (so vastly superior to the mind of such animals) is not produced by the human brain. 

Tuesday, July 21, 2020

Preservation of Mind and Memories After Removal of Half a Brain

The idea of a crucial experiment or critical experiment is an old concept in the world of science. Such an experiment is supposedly one that leaves one particular hypothesis standing, and rules out all rival explanations or rival hypotheses. The idea that there are such experiments has been criticized by some. A simpler idea is the idea of a sink-or-swim experiment. A sink-or-swim experiment is one that either leaves some hypothesis standing as a viable hypothesis (the “swim” situation) or causes the hypothesis to be discredited (the “sink” hypothesis).

Scientists have very often claimed that the human mind is produced by the brain, and that memories are stored in the brain. A very interesting question is: could you do a sink-or-swim experiment testing such hypotheses? The experiment has actually been done, not just once but many times. I will here use the term “experiment” for medical procedures that were usually done for medical reasons such as stopping very bad brain seizures in patients. Although the doctors who did such procedures may not have considered them experiments, we can consider them as experiments in the sense of testing a particular hypothesis about the brain.

The sink-or-swim experiment for the hypothesis that the brain makes the mind and the hypothesis that the brain stores memories is to surgically remove half of the brain, and see what the effect is on the mind and memory. Such an experiment has been done many times. Almost every time the result has been that there was no major effect on consciousness, no major effect or intelligence, and no major effect on memory. The memories of people who had half of their brains removed usually preserved the knowledge and life memories they had acquired.

This is a “sink” result for this sink-or-swim experiment. The results of such surgical operations decisively refute claims that the mind is the product of the brain and claims that the brain is the storage place of memories. But addicted to materialist dogma that the mind is merely the product of the brain and that memories are stored in brains, virtually no neuroscientists have paid attention to the results of these sink-or-swim experiments. In this regard, they are like fundamentalists who keep believing that the Earth is 6000 years old despite observational results indicating our planet is billions of years old.

I have in five previous posts (here, here, here, here and here) listed very much data relating to such experiments. In this post I will not restate that data showing that intelligence is well-preserved after removing half of the brain, but will mostly cite some data and cases I have not previously discussed.

I can start with the 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 re moved 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. Here are eight people who had half of their brains removed. Yet the people showed “no observable mental changes,” and “their memory was unimpaired for immediate and remote events.” The people could read, write, compute and learn just as if nothing had happened, and “there were no personality changes.”

A 1966 paper was entitled “Long-term changes in intellect and behavior after hemispherectomy.” The paper refers to operations in which half of a brain is removed, often to stop very bad brain seizures. This paper gives very detailed “before and after” IQ score data on 11 people who had half of their brains removed. Eight of the 11 people had the left half of their brain removed, and the other three had the right half of their brain removed. Every single one of the 11 people was able to get an improved IQ score on at least one of the tests taken after half of their brain was removed, a score better than a corresponding score they had got before half of their brain was removed.

Patient 1 (a P.G.) had an IQ of 128 before half of his brain was removed. After half of his brain was removed, he scored 142 on an IQ test. The paper tells us that this man with half a brain “obtained a university diploma after operation” and “has a responsible administrative position with a local authority.”

The same paper refers to previous results when removing half of a brain, and notes data suggesting that such an operation has little negative effect on intelligence. Referring to intelligence, we are told that McKissock reported “short term improvement in 13 of 17 cases,” that another researcher found “significant improvement in verbal intelligence scores in a variety of tests after operation in five of 35 cases, with temporary deterioration in two, the remainder unchanged.” We are also told that White “reports improvement in personality in 80% of 134 cases” in which half of the brain was removed.

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. 



In an article in the New Yorker magazine, we are told of a Christina Santhouse who had half of her brain surgically removed: “When I met her, she had taken her S.A.T.s and just finished high school, coming in seventy-sixth in a class of two hundred and twenty-five.” If your brain makes your mind, how could you finish in the top 34% of your class with only half a brain? The same article tells us of someone who had half of the brain removed, but made the dean's list in college, a list of the top-performing students on campus.

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.' ”

On page 59 of the book The Biological Mind, the author states the following:

"A group of surgeons at Johns Hopkins Medical School performed fifty-eight hemispherectomy operations on children over a thirty-year period. 'We were awed,' they wrote later of their experiences, '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.' " 

There is a reason why we can be confident that removal of half of a brain in hemispherectomy operations does not cause any major loss of learned memories.  If there was a case of any such thing happening, you can believe that it would be endlessly recited by those who wish for us to believe that memories are stored in brains.  But there is no such case, so we never hear materialists telling us about some person who suffered some dramatic loss of learned knowledge after having a hemispherectomy operation in which half of his brain was removed. 

Our professors very often make biology claims that are contrary to the low-level facts of biology. The table below lists various cases in which the fantasy biology of academia dogma diverges from biology reality. 

FANTASY BIOLOGY VERSUS BIOLOGICAL REALITY
Dubious Biology Claim Biological Reality
Brains store memories, probably in synapses or dendritic spines. Neither synapses nor dendritic spines last for even a tenth of the longest time that humans can remember things, and both are made up of proteins with lifetimes of only a few weeks.
DNA stores a blueprint or recipe for making the human body. DNA does not specify the physical structure of any of these things: an organism's body, its organ systems, its organs or its cells. 
Visible biological innovations arise from a combination of random mutations and natural selection, which improves the DNA of a species. It has not been proven that any visible complex biological innovation ever appeared because of random mutations and natural selection, and we know of a reason why mere DNA mutations could never produce a complex visible biological innovation: that visible physical structures are not specified in DNA.
Life appeared because of a lucky combination of random chemicals billions of years ago. Neither a living thing nor any of the building blocks of a living thing (proteins and nucleic acids with genetic information) has ever been produced through any experimental process that  realistically simulated early Earth conditions.
The building blocks of life have been found in outer space. No one has found in outer space either of the two actual building blocks of life: proteins or nucleic acids with genetic information.
Brain scans show your brain makes your mind. Brains scans actually show signal differences of less than 1% during thinking or recall, what we would expect from random variations.
Brain signals are real fast. Synaptic delays, synaptic fatigue and relatively slow dendritic transmission mean that signals in the cortex must be real slow.
The common descent of all life from a single ancestor is a fact. A shortage of transitional fossils and the lack of DNA corresponding to old fossils (because of DNA's half-life of 521 years) make the doctrine of common descent very unproven.
Chemically humans are almost exactly like chimps. 80% of proteins are different between humans and chimps.
Our minds can be explained neurally. There is no credible neural explanation for any of the main features of the human mind: memory, self-hood, consciousness, abstract thinking, and imagination.
We kind of understand how a speck-sized egg can progress to become a full-sized baby. We have no understanding of how this occurs (given a lack of a body plan in DNA), and do not even understand what causes cells to reproduce.
Memory and intelligence depend strongly on brain status. A person can lose half of his brain in a hemispherectomy operation, with little effect on memory or intelligence.

The image below reproduces the table above. 


biology myths

Thursday, July 9, 2020

Gender Differences in Brains Help Discredit Prevailing Dogmas About Brains

Many people are interested in differences between the brains of males and the brains of females, and differences between males and females in IQ tests and memory tests. A careful examination of this area provides some evidence against the claim that the brain is the source of human intelligence, and the claim that memories are stored in synapses of the brain.

The brains of males are significantly larger on average than females -- about 10% bigger. But we know that females tend to be shorter and weigh less than males. Some say that the relative size of female brains (female brain sizes compared to female body sizes) is no smaller than the relative size of male brains.  But in a scientific paper a scientist states, "After correcting for body height or body surface area, men's brains are about 100 g heavier than female brains in both racial groups."  That difference of 100 grams is about 7% of the total weight of a male brain (about 1350 grams). 

So using the idea that the human mind is produced by the brain, we should expect that males do about 7% better at school and about 7% better in IQ tests.  But this is not at all the case. Males and females do about the same on IQ tests, with a difference of less than 1% or 2%.  In the United States females tend to get just as high academic grades as males.  In this regard, the claim that the brain is produced by the mind fails the observational test. 

Now let's consider human memory. The standard academic dogma (unsupported by any facts) is that memories are stored in the synapses of brains. The persistence of this dogma is mystifying, given what we know about the instability of synapses. Humans can reliably remember things for longer than 50 years, but individual synapses do not last for years. The proteins that make up synapses are very short-lived, having an average lifetime of only a few weeks. 

Wikipedia.org states, "Multiple studies[22] [23] have found a higher synaptic density in males: a 2008 study reported that men had a significantly higher average synaptic density of 12.9 × 108 per cubic millimeter, whereas in women it was 8.6 × 108 per cubic millimeter, a 33% difference." The 2008 study mentioned is the study "
Gender differences in human cortical synaptic density" you can read here

Now, this 33% difference is quite a big difference, much bigger than the brain size difference previously mentioned. Under the assumption that synapses are the storage place of memory, we should expect (given this 33% greater synapse density in males) that either males tend to have stored much more memories than females, or that males are better at remembering things than females. But  such things are not true. 

There is no evidence that males store more memories than females. One good way of testing whether males store more memories than females is simply to look at academic scores. If males tended to store more memories, they would tend to have higher academic scores than females. But females do just as well as males in tests of learned information. 

Below is a quote from an article in the New York Times indicating that boys do not do better than females (on average) in school tests:

"The study included test scores from the 2008 to 2014 school years for 10,000 of the roughly 12,000 school districts in the United States. In no district do boys, on average, do as well or better than girls in English and language arts. In the average district, girls perform about three-quarters of a grade level ahead of boys. But in math, there is nearly no gender gap, on average. Girls perform slightly better than boys in about a quarter of districts...Boys do slightly better in the rest."

Here are some quotes from the scientific paper "The Role of Sex in Memory Function: Considerations and Recommendations in the Context of Exercise": 

"Females tend to outperform males in episodic memory function....Females tend to perform better than males in verbal-based episodic memory tasks, as opposed to spatial-based memory tasks []. Females generally access their memories faster than males [], date them more precisely [], and use more emotional terms when describing memories []. Superior verbal memory for females also appears to be independent of intelligence level []. Additionally, females also have greater specificity for events imagined to occur in the future []. In general, females outperform males on autobiographical memory (particularly with high retrieval support via verbal probing []), random word recall [], story recall [], auditory episodic memory [], semantic memory (driven by superiority in fluency) [], and face recognition tasks [,]."


So the paper is telling us that female memory performance is better than male memory performance in all these areas. But how can that be, if males have a synaptic density 33% greater? We have here additional evidence that there is no truth in the common claim that memories are stored in human synapses. 

Sunday, June 28, 2020

Long Article Tries to Show Neural Memory Storage, but Gives No Real Evidence for It

In Discover magazine, there was recently a long article entitled “What Happens in Your Brain When You Make Memories?” An article like this is an attempt to convince us that scientists have some good understanding of how a brain could store memories. But the article completely fails at such a task, and provides no substantial evidence for any such thing as neural memory storage.

We are told the following: “In the 1990s, scientists analyzed high-resolution brain scans and found that these fleeting memories depend on neurons firing in the prefrontal cortex, the front part of the brain responsible for higher-level thinking.” There is no actual evidence that the front part of the brain is responsible for high-level thinking. You can read here for evidence that specifically contradicts such a claim. 

The quote above includes a link to a brain scanning scientific paper. That paper provides no evidence that memories depend on neurons firing anywhere. In any type of brain scanning study, the two main questions to ask are:  how many subjects were used, and what was the percent signal change detected during some supposed activation of some brain region? The paper does not tell us either of these things. It mentions some brain scanning study, but does not tell any details of how many subjects it used, or what percent signal change was detected. We can only assume that the study was one of those ridiculously common studies that either: (1) used too small a sample size to get a result of good statistical power, or (2) detected only meaningless signal changes such as less than 1%, the type of differences we would expect to get by chance, or (3) had both of these problems. When scientists use impressive sample sizes or when they get impressive brain scanning results regarding percent signal changes, they almost always tell us about such a thing. When there is a failure for a paper to mention either of these numbers, we should assume it is because the numbers were not impressive, and not good evidence.

The article then states the dogma that memories form when synapses are strengthened: “When a long-term memory is formed, the connections between neurons, known as synapses, are strengthened.” There is no evidence that this is true. When stating the sentence above, the article has a link to a paper that provides no evidence that memory storage involves synapse strengthening.

In fact, there are reasons why it cannot be true that memories are formed by synapses being strengthened. The first is that synapses are too unstable to be a permanent storage place for memories. The proteins in synapses have an average lifetime of only a few weeks. But humans can accurately remember things for 60 years, which is 1000 times longer than 50 weeks. Synapses do not last for very long. The paper here says that half-life of synapses is "from days to months." 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). 

The second reason is that humans are able to instantly form permanent new memories at a rapid clip. This was shown in an experiment in which humans were able to remember fairly well images they were only exposed to for a few seconds. The experiment is described in the scientific paper “Visual long-term memory has a massive storage capacity for object details.” The experimenters showed some subjects 2500 images over the course of five and a half hours, and the subjects viewed each image for only three seconds. Then the subjects were tested in the following way described by the paper:

"Afterward, they were shown pairs of images and indicated which of the two they had seen. The previously viewed item could be paired with either an object from a novel category, an object of the same basic-level category, or the same object in a different state or pose. Performance in each of these conditions was remarkably high  (92%, 88%, and 87%, respectively), suggesting that participants successfully maintained detailed representations of thousands of images."

Let us imagine that memories were being stored in the brain by a process of synapse strengthening. Each time a memory was stored, it would involve the synthesis of new proteins (requiring minutes), and also the additional time (presumably requiring additional minutes) for an encoding effect in which knowledge or experienced was translated into neural states. If the brain stored memories in such a way, it could not possibly keep up with remembering most of thousands of images that appeared for only three seconds each.

In the Discover magazine article, we are then told an inaccurate legend of scientific achievement: “ In a 2012 Nature study, Tonegawa and researchers at MIT and Stanford University used optogenetics to demonstrate that our memory traces do indeed live in specific clusters of brain cells.” No, Susumu Tonegawa and his colleagues did not do any such thing. In the post here you can read a rather lengthy discussion of various memory-related papers authored by people working at Tonegawa's MIT memory laboratory. These papers suffer from a common defect of using too-small sample sizes. Again and again when looking up the memory-related papers authored by people working at Tonegawa's MIT memory laboratory, I found papers that used sample sizes so small that were not good evidence for anything. In a neuroscience experiment, the absolute minimum for a somewhat compelling result is 15 animals per study group (and in most cases the number of animals per study group should be much higher, such as 25 or more). But again and again when looking up the memory-related papers authored by people working at Tonegawa's MIT memory laboratory, I found papers that used sample sizes of 10 or smaller. Such papers are not good evidence for anything.

In the Discover magazine article, we have a clear description of the utterly fallacious experimental technique used by Tonegawa, a technique that has given him the wrong idea that he has found a memory in brains. Here is what the article says:

"In the paper, the research team describes how they pinpointed a particular group of neurons in the hippocampus, a part of the brain involved in the formation of long-term memories, that start firing under certain conditions. In this case, the researchers did so by having mice explore an unfamiliar cage. '[Then] you give [the mouse] mild electric shocks to their footpads,' says Tonegawa. 'And the mouse will immediately form a memory that this cage is a scary place.' The next day, says Tonegawa, when the mice were placed in the cage without being zapped, this conditioning led them to fear that environment. The researchers later injected the rodents with a protein that can trigger brain cells — specifically, the neurons in the hippocampus that the scientists were targeting — by flashing them with blue light. ''These proteins have a chemical property to activate cells when light of a particular wavelength is delivered,' adds Tonegawa. Then, when the scientists flashed the mice with pulses of light in an entirely different environment, the neurons in the hippocampus they had labeled with the protein sprung into action — and the mice froze in place. The researchers think the animals were mentally flashing back to the experience of being shocked. 'That’s the logic of the experiment,' says Tonegawa. 'You can tell that these neurons, which were labeled yesterday, now carry those memory engrams' ”

There are two reasons why this technique is fallacious and unreliable, and does not provide any evidence at all that memories are stored in the brains of these mice. The first is that when the brains of the mice are being flashed with pulses of light, this is a stimulation effect that itself may be causing a freezing effect causing a mice to “freeze in place,” even though no fearful memory is being recalled by the mice.  In fact, it is known that stimulating many different regions of a rodent brain will cause a mouse to “freeze in place.” A science paper says that it is possible to induce freezing in rodents by stimulating a wide variety of regions. It says, "It is possible to induce freezing by activating a variety of brain areas and projections, including the hippocampus (Liu et al., 2012), lateral, basal and central amygdala (Ciocchi et al., 2010); Johansen et al., 2010; Gore et al., 2015a), periaqueductal gray (Tovote et al., 2016), motor and primary sensory cortices (Kass et al., 2013), prefrontal projections (Rajasethupathy et al., 2015) and retrosplenial cortex (Cowansage et al., 2014).”  Therefore there is no reason at all to assume that the “freeze in place” is actually being caused by a recall of a memory. The “freeze in place” effect could be caused simply by the stimulation being delivered to the brains of the mice, without any recall occurring.

The second reason why such an experiment is no evidence at all for memory storage in a brain is that “freezing behavior” in mice is very hard to reliably measure. In a typical paper, judgments of how much a mouse froze will be based on arbitrary, error-prone human judgments. The reliable way to measure fear in mice is to measure their heart rate, which goes up very suddenly and rapidly when mice are afraid. But inexplicably, neuroscientists almost never use such a technique. Since scientists like Tonegawa do not use reliable techniques for determining whether rodents are afraid, and since the experiments depend on assumptions that the animals were afraid,  we should have no confidence in the results of experiments like those described above.


freezing behavior in rodents

The Discover magazine article then proceeds to describe some work by neuroscientist Nanthia Suthana, in which epilepsy patients had their brains scanned when using video games.  We are told that some evidence was found that some kind of brain wave called theta oscillations was more common during memory recall. But we are not told how large an effect size was found, and have no way of knowing whether it was merely some borderline result unlikely to be replicated. We are not given a link for any paper that has been published,  and we are told that there are merely two papers "in peer review." We have no mention of how many subjects were used.   And memory retrieval is something quite different from memory storage.  These are all quite a few reasons why such an experiment is not anything like substantial evidence for any neural storage of memories.

The last gasp of the Discover article is to claim that "Sah and his colleagues used optogenetics in rats to identify the circuitry in the brain that controls the return of traumatic memories."  The "return of traumatic memories" refers to memory retrieval, which is an entirely different thing from memory storage.  We are given a link to some study behind a paywall, and the abstract mentions no actual numbers, meaning we have no basis for any confidence in it.  Given the rampant sample size problem in experimental neuroscience, in which too-small study groups are being used in most studies, we should have no confidence in any study if we merely can read an abstract that does not mention how large a study group was used.

Despite its long length, the Discover article fails to give us any solid piece of evidence suggesting that memories are stored in brains.  The Discover article is a kind of Exhibit A to back up my claim that scientists have no actual evidence basis for believing that memories are stored in brains.  Their "best evidence" for such claims are "house of cards" studies that do not meet the requirements of compelling experimental science.  We have no solid scientific basis for believing that memories are stored in brains, but we do have good scientific reasons for believing that memories cannot be stored in brains.  One such reason is that people do not suffer substantial losses of learned information when half of their brain is removed in hemispherectomy operations.  See the paper here for a discussion of 8 people who had "no observable mental changes" after removal of half of their brains. The paper specifically mentions "their memory was unimpared."  The second reason is that the proteins that make up the synapses of the brain have average lifetimes 1000 times shorter than the maximum length of time (60 years) that humans can retain memories.