Humans manufacture various types of fast-retrieval systems, such as computers and books. A simple book with page numbers and an index is a fast-retrieval system, allowing you to get information about some topic very quickly. Below are seven things typically found in fast-retrieval systems.
Characteristic #1: Addressing or Position Notation
Addressing is some setup where particular spots in a system have addresses or coordinates. In a book addressing is implemented as page numbers. Without such page numbers, you could never use the index of a book to very quickly find information in the book. The index of the book only works when there are numbered pages that the index can refer to. Computers also use an addressing or position notation system. Every little spot on a computer's hard drive has an address or positional coordinate that can be used internally by the computer.
Conversely, brains have no addressing system, no position notation system, and no coordinate system. Neurons don't have neuron numbers or neuron coordinates, and synapses don't have synapse numbers or synapse coordinates.
Characteristic #2: Indexing
Indexing is some setup that allows a fast retrieval of information using addresses or coordinates or numbered positions. An index typically uses a sorted list. For example the index of a book contains a sorted list of topics in the book, with a page number or page numbers next to each of the topics. Computers also use indexing, and online services such as Internet search engines make very heavy use of databases that rely heavily on indexes.
Conversely, there are no indexes in the brain.
Characteristic #3: Sorting
Sorting is used in indexes, but sorting can be used by itself to allow fast retrieval of information. When I was a boy long before the Internet was invented, a key resource I used was a multi-volume encyclopedia set such as the Encyclopedia Brittanica. The set consisted of many volumes, with the first volume covering topics beginning with A, and the last volume covering topics beginning with Z. Each volume was alphabetically sorted. So, for example, in the A volume the article on aardvarks came near the beginning, and the article on the Aztecs came near the end. With such a sorted arrangement of topics, it was easy to quickly find information on almost any topic. Computers also make use of sorting to allow quick retrieval of information.
Conversely, there is no sorting going on in the brain. Neurons and synapses have fixed positions in the brain. There is no way for a brain to sort its neurons or synapses, and no sign that any brain components are sorted.
Characteristic #4: A Nondestructive Position Focus Mechanism
A position focus mechanism is some mechanism allowing information to be read from some position that is the current reading position that can be changed. The setup of a book (with a binding and many pages) allows a nondestructive position focus. You simply open the book to one of its pages, and that is the current reading position. Computers with hard drives also use a position focus system. They have a read/write head that can be moved to a spot on a spinning disk. That spot is the current reading position. A good position focus mechanism is one that is nondestructive, allowing you to move to any reading position without damaging information in the system.
We can imagine information storage systems that would fail to have a nondestructive position focus mechanism. You could write information on all the dried leaves in your backyard. But then if you tried to read from some particular position, you would have to step on many leaves, and mess up the information in them. Or, you could write very much information using your fingers, on the wet sand of a beach. But if you were to try and read from a particular spot, you would walk over the lines, and destroy some of the information. Similarly, it would not work to store information by putting pages in a big bag. There would be no position focus mechanism allowing a fast retrieval.
Brains have no known position focus mechanism. There is nothing like a neural cursor that travels from one position in the brain to another, implementing something like a current reading position. There is nothing in the brain like a read/write head of a computer. Eyes have a physical mechanism allowing them to focus on one particular spot, but there is no sign in the brain of any mechanism allowing a physical focus to occur on one small set of neurons, something like a position focus mechanism.
Characteristic #5: Hierarchical Organization
In something like a printed encyclopedia set, information is stored using a hierarchical organization. The organization goes like this: pixels are organized into characters, which are organized into words, which are organized into sentences, which are organized into paragraphs, which are organized into topic articles, which are organized into volumes. Such an organization facilitates the fast retrieval of information.
Something rather similar goes on in computers. Computers use a folder system or directory system that can be hierarchically organized. So, for example, in the screen shot below we see a file called stdole.dll that is in the subdirectory within an stdole directory that is within a GAC directory that is within an assembly directory that is within a Windows directory. When there are very many files on a computer, it is much faster to find files with such a hierarchical organization than if all of the files were in the same directory or folder.
Characteristic #6: Places for Permanently Storing the Fast-Retrieved Information
Fast-retrieval systems such as books and computers have places for permanently storing information. The printed pages of a book will store information for more than a century. A computer will store information for many years, even if the power is turned off.
Conversely the brain seems to have no place suitable for the storage of fast-retrieved information. The main theory of memory storage in the brain is that memories are stored in synapses. But synapses are physically unstable. On a molecular level, the proteins that make up synapses are short-lived, having average lifetimes of two weeks or shorter.
On a larger structural level, synapses are unstable. Synapses are so small that it's almost impossible to track the lifetime of an individual synapse. But we know that synapses are attached to larger units called dendritic spines, rather like sewer lines or electrical lines are attached to a house. Dendritic spines are large enough to be observed with high-powered microscopes. Such observations tell us that dendritic spines are pretty short-lived.
Characteristic #7: Use of a General-Purpose Encoding System
Books and computers both use a general-purpose encoding system, capable of storing an almost infinite variety of information. In books the encoding system is the alphabet of a particular language. In computers the encoding system involves multiple protocols such as the ASCII protocol by which English characters are represented as decimal numbers, and a decimal-to-binary protocol by which decimal numbers can be represented as binary numbers such as 0000000000001110.
No one has ever discovered any type of general-purpose encoding system in the brain. The only known encoding system in the brain is the genetic code, a very limited type of encoding system under which certain triple combinations of nucleotide base pairs stand for particular amino acids. The same system is used in all parts of the body, including your feet. No one has ever discovered any type of encoding system by which something such as English text could be represented as stored information found in neural states or synapse states. No one has ever found a single English word or a single image stored in a brain after examining brain tissue with a microscope.
A scientific paper notes the lack of any encoded information permanently stored in synapses:
"Synapses are signal conductors, not symbols. They do not stand for anything. They convey information bearing signals between neurons, but they do not themselves convey information forward in time, as does, for example, a gene or a register in computer memory. No specifiable fact about the animal’s experience can be read off from the synapses that have been altered by that experience.”
Conclusion
The human brain bears no physical resemblance to a device for the fast retrieval of information, and has none of the main characteristics of systems that are devices for the fast retrieval of information. But we know that humans can retrieve information at instantaneous speeds. This is routinely shown on the show Jeopardy, where contestants retrieve information and speak an answer (stated in question form) pretty much the instant that the host finishes reading a question (stated in answer form). Any performer singing a Gilbert and Sullivan patter song will be retrieving information at a speed of roughly three words per second, and I can mentally recall some of their songs at a rate of five words per second.
(1) the US phone system if no one's phone number had ever been published;
(2) a vast post office with countless post office boxes, none of them numbered;
(3) a city in which none of the streets were named, none of the buildings had an outside identifier, none of the apartments had apartment numbers, and none of the houses had street numbers.
Imagine how hard it would be in any of such things to navigate to a precise location -- a particular post office box, a particular phone, a particular chapter of a particular book, or a particular apartment. That's the kind of situation that should exist in a brain storing abundant memories, because there is no coordinate system in a brain, and neurons don't have neuron numbers or something like a brain longitude and latitude. Instantaneous recall of rarely recalled memories and rarely recalled facts should be impossible if our memories are stored in brains. The fact that we routinely perform such instantaneous recalls is strong evidence our memories are not mainly stored in brains.
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