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.