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Our future, our universe, and other weighty topics


Sunday, March 29, 2015

New Study Suggests Memory is a Great Unknown

I often hear inaccurate claims about what neuroscience states or what neuroscience knows or what neuroscience has proven. These type of misstatements take several forms. One very common type of misstatement is when people confuse the opinions of neuroscientists with neuroscience itself. The two are not identical. Neuroscience consists of the observations and experiments that have been published in neuroscience journals. Neuroscientists may hold quite a few opinions that are not justified by such observations and experiments, largely because such opinions are expected within their particular intellectual set. Such opinions should not be classified as neuroscience, but as the typical opinions of neuroscientists.

Another common type of misstatement is when someone glibly claims that neuroscience has proven some particular claim, when in fact neuroscience may have merely hinted at such a thing as a possibility. One example may be claims that memories are stored in synapses that link together brain cells. In fact, we have no real understanding of how memories are stored.
A synapse is shown in blue

A recent article in the online version of Scientific American seems to highlight how little neuroscientists really know about this matter. The article starts out by telling us that the standard doctrine has been that memories are stored in the synapses that connect brain cells. The article puts it his way: “The idea that synapses store memories has dominated neuroscience for more than a century, but a new study by scientists at the University of California, Los Angeles, may fundamentally upend it: instead memories may reside inside brain cells “

Neurobiologist David Glanzman at U.C.L.A is quoted as saying this work “implies to me that the memory wasn't stored in the synapse.” The article then suggests that perhaps memories are really stored inside a brain cell itself.

Such a development should cause us to have little confidence in either the claim that memories are stored in synapses or the claim that memories are stored in brain cells. Similarly, if scientists one day suddenly announced that the sun gets its power not through thermonuclear fusion but through some process called photon transduplication, then we should doubt very much that either explanation is valid. In general, when someone changes his story to some different explanation, it is best to be skeptical about the new explanation for quite a while.

Rather than claiming we have some clear understanding of the relation between the brain and memories or consciousness, it would be more candid and honest for us to admit our profound ignorance about the topic. There are many facts and findings that conflict with the simplest assumptions one can make about the brain, that it is some kind of machine that is the sole cause of your consciousness and the sole storehouse of your memories. I have written two previous blog posts (here and here) discussing some of those facts and findings.

Rather than repeating any of these items in this post, I will discuss additional things not listed in those posts. The first is the strange case of Phineas Gage. Gage was a railway worker who in 1848 had a three feet long javelin-like piece of iron (one and a quarter inches or 3.2 cm. in diameter) accidentally spear through his skull, passing right through his brain, and producing a 2-inch exit wound. His brain suffered about the same onslaught a brain would suffer if you held two 45 caliber pistols barrel to barrel, one in your left hand and one in your right,and then fired them into someone's skull. The path of entry was entirely through the brain, not merely on the edges of his brain.

But Gage did not die, and apparently did not even lose consciousness (or perhaps suffered only a short loss of consciousness). A medical report in 1850 reported that Gage was “quite recovered in faculties of body and mind.” It's true that after the injury people reported that he became rude, profane, and capricious, but such problems are rather trivial compared to the results we would expect from such an injury: death, loss of all memory, or a great loss of intellect.

How is it that we can reconcile the case of Phineas Gage with the assumption that your brain is the sole source of your consciousness? It is not at all clear.

Here is another very strange fact to consider. According to scientists, the male human brain has 6.5 times more grey matter than the female brain. But the female brain has 9.5 times more white matter. Scientists say that grey matter is a lot more involved in thinking. So the theory that your brain is the sole producer of your consciousness would seem to predict that there should be the most radical difference between the male intellect and the female intellect – like the difference between two species on two different planets, or perhaps the difference between a man and a squirrel. But there is no such difference. The differences are instead relatively trivial. We see males doing about 10% better on the SAT Math tests, but according to the difference in grey matter, we might expect that to be a 600% difference.

This is a huge paradox, and there are many other paradoxes involved with the brain. The Paradoxical Brain is a 466-page book published by the Cambridge University Press. According to the summary on www.goodreads.com, “The Paradoxical Brain focuses on the phenomenon whereby damage to the brain can actually result in enhancement of function, questioning the traditional belief that lesions or other negative effects on the brain will result in loss of function.” How are such paradoxes compatible with the simplistic assumption that your consciousness is nothing but a by-product of your brain?

If you give such paradoxes and anomalies some careful consideration, then the next time you hear some dogmatic neurologist claiming to understand your consciousness or your prospects of survival after death, you can ask yourself: does this person really understand these profound mysteries, or is he merely a pretentious “knowledge poseur” who is claiming to understand matters far beyond the ken of any human?