General introduction to word meaning and terminology.
Definitions of Memory
Alphabetical listing of terms.
(provide links to major on-line dictionaries in cognitive science, philosophy, etc.)
 

The memory tangle.
(image source)
General introduction to word meaning and terminology

One way to start thinking about the nature of word meaning is by thinking about a human child learning its first words. A one year old human knows a lot about the world. A baby starts to name objects at about the same time that a baby learns its place in the world (and can recognize itself in a mirror) and begins to be able to perform complex motor tasks (such as pointing at objects). Seeing an object (or hearing a sound) and then responding by speaking a particular word is a complex sensory-motor task. Before a baby is able to name objects, it prepares the brain circuits that are involved by a practice method that involves mimicry, repeating sounds that other people (or animals) make. A child learning its first words already knows a lot about the objects being named. Meaning comes before the words.

It would be ludicrous to claim that a baby knows the meaning of words in terms of other words. Word meaning is built on non-linguistic experience of the world. Yet, by the time children learn to read and write, we start forcing them to make use of dictionaries which attempt to "define" a word's meaning in terms of more words (or if you are lucky, also a picture). We become so familiar with attempts to explain the meaning of one word in terms of other words that we often forget what is going on in a verbal definition of a word. Verbal definitions are just attempts to use a person's existing non-verbal understanding of the meaning of some words in order to suggest the non-verbal meaning of additional words. If you know what "green" and "book" are through your personal experience of green objects and books, I can tell you that "grook" is my word for a green book, and you can understand "grook" even if you have never heard the word before.

Now, "grook" is a made-up example of jargon. Imagine the people who work in libraries returning books to the shelves. Imagine two such workers trying to cooperate in sorting a cart full of books that need to be re-shelved. In the imagined library, the shelves are very high, so one worker goes up a ladder while the other hands the books up. A word like "grook" might be a useful shortened form of "green book"; we can imagine a whole set of jargonistic terms for "big book" (bik), "skinny  book" (skik), "red book" (rook), etc. Some of these new words will present special problems, because they are words that already have existing meanings (for example, "rook").

In exploring memory, we face the problem of dealing with the special jargon that is used by the specialists who study memory. The word "memory" itself is a good example. Speakers of the English language understand the word "memory" in the ways we all use "memory" in every day conversation. However, scientists who study the details of memory (such as how a brain stores a memory) use the word "memory" in special ways that are outside of the experience of most people. Thus, if we start to explore the writings of philosophers, psychologists, and neuroscientists, we will be confronting uses of the familiar word "memory" that are different from what we normally experience in everyday life.

Perhaps the worst thing about the "grook" problem is that specialists seldom take the time to try to explain their jargonistic use of words. Everyone within a particular sub-discipline (such as book re-shelving) may know that a special jargonistic term such as  "rook" means "red book", even if nobody ever bothers to explain this specialized use of the word "rook" to the rest of us. It might be argued that when ever a new meaning for an existing word arises, people should stop and construct a new word so that confusion cannot arise over the multiple meanings of words. Unfortunately, the introduction of new words into a language is more difficult than simply borrowing existing words for new jobs.

The production of new words that can help us avoid confusions about the multiple meanings of words is a tricky problem, it is a distributed and often invisible social process. People who study memory have found that there are many forms of memory. Special terms have to be developed so that memory specialists themselves are not confused by all of their own special jargonistic meanings for the word "memory". A good example of this jargon refinement process is found in the use of the word "atom". Like "memory", "atom" is an ancient word. The ancient Indo-European (IE, abbreviations are another great tool of the jargoneer) root "tem" (meaning to cut or fragment) is one of the IE root words for what was probably among the first words humans developed. The act of cutting is so common and important to human experience that the Indo-Europeans had several words for various types of cutting. For example, there was also also skei, rei, dap and da (see conscious,river, and time).

Since cutting is such a universal human activity, the word "atom" seems like it must have been a strange invention. The idea of something which cannot be cut into smaller parts is a radical thought that is contrary to the common human experience of being able to keep splitting objects into smaller pieces. However, the logical operators "and", "or", and "not" are probably built into animal brains, so familiarity with a physical process such as "fragmentation" is in some sense naturally going to suggest to people its opposite: the possibility of things that cannot be fragmented. For example, the living world provides examples of indivisibility: if you cut an animal into pieces you destroy the "property" of life that was in the intact organism. Also, in normal human experience, our conscious selves are unitary. Multiple personality disorders are rare and aberrant. A unified and indivisible self is experienced by most people and is a fundamental part of their lives. Like many rural people, the Indo-Europeans had an intimate sense of the natural world and their place in it. The Indo-European root word kailo which is the source of both "whole" and "holy" suggests that they thought of holiness in terms of a kind of undivided unity.

These examples indicate that the idea of non-fragmentable essence of life was part of an ancient dualistic view that eventually led into a distinction between an invisible world of the non-material and the visible world of material objects. Non-material objects are of special concern to us here, because memories themselves have often been imagined to be non-material. Explaining the material basis of memory has been one of the triumphs of modern science and is a topic that will be a major focus for us in our exploration of memory. The distinction between animate and inanimate objects is as old as humanity. I suspect that the idea of non-material spirits is more recent. The Indo-European root word ane, to breath, is old. Words like spirit and soul are newer constructions. However, for now, I want to put the important issue of non-material souls off to one side and restrict our thinking to the physical. The idea of physical objects that cannot be cut became popular with ancient philosophers who ignored the evidence of the senses which suggests that in practice we can cut most things into pieces. Philosophers tried to imagine how logic can lead us to an understanding of invisible things. In their search for solid foundations of logical thought, philosophers imagined that there might be physical atoms. The logical alternative to atoms is some kind of infinite regress of stacked turtles or tinier flies upon tiny flies. With pranksters like Zeno going around describing paradoxes arising from infinities, many philosophers felt more comfortable with finite atoms than with infinitely small fragments. So the term "atom" was around for thousands of years before anybody even knew if it was more than a fabrication of nervous philosophers. The word "atom" was a challenge thrown down, a stimulus to reductionism and a search for the bottom turtle of the turtle stack.

When the characteristics and features of the physical entities that we now call "atoms" were finally discovered by physicists, there was already diverse jargon for dealing with different kinds of atoms. This diversification of types of atoms can be traced back into the ancient past. The Greeks thought that earth, air, water, and fire were fundamental substances. Were there specific water atoms, fire atoms, water atoms, etc.? By the time physicists were defining the properties of atoms (And even started splitting atoms! This is a great example of the inertia of words. How can physicists keep using the term "atom" to refer to things that they know CAN be fragmented?), chemists had shown that there are dozens of different types of chemical elements. We have carbon atoms, oxygen atoms, hydrogen atoms, nitrogen atoms, etc. In talking about the structures of molecules the jargonistically correct terminology is to just say "water molecules are composed of two hydrogens attached to an oxygen." For brevity, we leave out the word "atom"  since it is now implicit in the description of water in terms of a combination hydrogen and oxygen. Another example of diversification of terminology is the word "isotope" which refers to different atomic variants of the same type of atom; thus we have hydrogen, deuterium, tritium. This ancient search for the atom brought us to a very strange place, the science of quantum mechanics. It is so strange that Einstein refused to accept it, saying that God would not play dice games in order to make the universe function. After nearly a century of people hoping that they could trust in the "fact" that no matter how strange quantum mechanics is, we at least had the solid ground of atoms under their feet, this seeming vindication of the Greek atomists was never firm (neutrons, protons, electrons, quarks) and it is now being shaken apart. It seems that what we called the "atom" is truly not the bottom turtle. Physicists have been continuing Einstein's search for a unified theory of electromagnetism and gravity. This search has led to the idea of even smaller vibrating "strings" and membranes that are the components of "atoms". Will the digressions ever really end? Is there an end to the cutting? Do REAL atoms exist?

Returning to memory, as for "atom", a similar process of diversification of terminology for dealing with memory is underway. In the next century when a comprehensive theory of the physical basis of memory is in place, we will have neuroscience's equivalent of the chemist's periodic table of the elements and students will memorize not only the names of the different types of chemical elements, but also the names of the different types of memory processes that exist in the human brain. Unfortunately, the biology of memory is still in a rather primitive state, so we are rather like the ancient alchemists, still unsure if water is elemental or a compound substance. Here is a list of some currently recognized memory types:

                                        working memory
                                        short-term memory
                                        long-term memory
                                        implicit memory
                                        explicit memory
                                        procedural memory

This list of memory types is like the ancient Greek's list of elemental types (fire, water, air, etc.) in that it is hopelessly naive. However, until neurobiologists finish working out the details of how parts of the brain produce different types of memory, this short list will have to suffice as a first approximation of the true diversity of memory types. Definitions for these types of memory are given below, in much the same way that the ancient Greeks once defined fire, water, and air.

If our current understanding of memory is really as primitive as I have claimed, then does it make sense to even bother trying to give firm definitions of our terms? Did the Greeks really have any sensible idea of what "fire" is? This is the method of science: start anywhere and keep working until you do get to the end. If the ancient philosophers had not tried to explain the universe in terms of water, fire, air, and earth then the scientific enterprise would never have gotten started. There is nothing wrong with starting a journey in the wrong direction as long as you are able to turn around. This is the power of science; no matter how wrong it is, it has the power to change itself and move towards what is correct.

Defining Memory
Now, having explained that the meaning of "memory" is a complex issue, does it make sense to try to provide a short verbal definition of "memory"? Yes. There must be a common core concept of memory that applies to all of the subtypes of memory or else we would not call them all memory. Here is the core concept of memory, "to recall the past." Notice that it is more of an active PROCESS than is implied by "retention". If I cut the shape of a letter into the surface of a rock, the rock retains the shape of the inscription, but we do not say that the rock remembers what I wrote on it. Related to old roots smer and men?

Technical definition of Memory. "Memory" is a general term used to refer to a broad category that includes as its members a diverse collection of types of memory all of which are functions of the mind by which particular functional states of the mind can be kept in the mind for later use in future functions of the mind.

Note: "memory" is really even more general than the above definition indicates. We can talk about memory in physical systems that are simpler than a mind. However, the original meaning of "memory" is in the context of the human mind, and this is the focus here.

The above definition of "memory" is a technical definition that needs to be put into its proper context. We can begin to do so by comparing the technical definition to a common definition:

Common definition of Memory. The mental faculty of retaining and recalling past experience.

In comparing these two definitions, there are several correspondences that are clear:
    common                                                           technical
"the mental faculty" = "functions of the mind involving particular functional states of the mind"
"retaining"               = "functional states of the mind can be kept in the mind for later use"
"recalling"               = "later use in new functions of the mind"

The most important difference between the common and the technical definitions of memory concerns the unitary nature of the common definition which contrasts with the emphasis on the "diverse collection of types of memory" that is in the technical definition. Historically, "memory" has been used by people in everyday life to refer to whatever type of remembering they have experience with. We all experience several types of remembering, but when we talk about our memories we usually just talk about the CONTENTS of the memories, not our subjective experience of how one memory may feel different from another. Thus "past experience" means the "objective content" of past experience that we want to share with someone else, not the personal subjective feelings of our personal memories.

function, states, mind

brain

categorization

conscience  The mental faculty of knowing right from wrong. Based on the Indo-European root word skei, meaning to cut or split. The Latin word scire, meaning to separate or discern was the source of the word science and its meaning "to know". (See categorization) If we perceive the world as a unified whole, then we can end up ignoring the details of its components. It makes sense for an animal brain to clump things together into functional wholes. You do not want to be distracted by the complexity of motion in a heard of animals when you are sneaking up on the heard. But when you get close enough you do want to be able to spot the important details, like the location of a new-born calf or a lame member of the heard. We become aware of the details of the world by cutting what we perceive into pieces. It is interesting that our language closely links the idea of distinguishing right from wrong to this "cutting" aspect of consciousness. We see this link in the Biblical story of Adam and Eve. Eating of the Tree of Knowledge allows people to know right from wrong; they become conscious of the fact that they are naked. This is a great metaphor for the power of cultural knowledge and folk-ways. In many societies, nakedness is no big deal. Within the Hebrew culture it was. The Hebrews were engaged in a long battle of survival as a rather austere patriarchal society against more settled and earth goddess-oriented peoples. Since there are more Indo-European words for male lineage relations, it is thought that the Indo-Europeans were patriarchal. It is interesting that there are few Indo-European root words for fruits; abel (apple) seems to be the only one.

conscious

consilience

dream  Patterns of weakly-conscious brain activity during sleep. Go to the dream page.

etymology  The origin and historical development of a word. The etymology of "etymology: a compound word combining ETYMON and -LOGY. Etymon is from the Greek etumos (true, real).

future  From the Indo-European bheu, meaning "to be, exist, grow." A derivative word of this root word is bhu-tu, meaning "that which is to be." This origin of the word "future" seems to capture the idea of the future as growing out of the past.

history

idealism

Indo-European  See Proto-Indo-European

knowledge  Physiological definition: what is known by perceptual experience and reasoning, a function of the brain. There is also cultural knowledge, see meme. Indo-European root: gno, to know. In modern times, we often think about wisdom from rationally acquired knowledge, but the word "wisdom" is from a different source having more to do with the senses than with reasoning (see wisdom).

language  (also see script)

learning  Within modern neuroscience, the terms "learning" and "memory" are closely linked by the following conceptual formula: when ever an animal learns something, memories must be stored; what is learned is stored in memory. The English word "learn" is from the Indo-European word leis, meaning to track or follow. Germanic liznon, "to follow a course (of study). Old English learnian, to learn. If there are tracks to follow, we could call the tracks on the ground a kind of memory.

man  I wonder if it is coincidence that we know our species as "man", the same word that means "hand" in Indo-European. When human language was developing, the human hand may have seemed like our most important physical feature. If you look at the sensory and motor maps in the human brain, the number of neurons devoted to the human hand is "striking". Some anthropologists have suggested that the human ability to throw projectiles by hand may have been one of the most important advances in human evolution. Even the crafting of the early stone tools was a type of throwing of a striker against the target stone. In comparison to humans, chimps are very clumsy about throwing. Another Indo-European root word is men, "to think", which is the source of our word "mind". Is it coincidence that this word for "to think" is so similar to the word man? Another similar Indo-European word is med, meaning "to take appropriate measures" and is the root of words like "medicine", one of the first systematized areas of human knowledge.

meme  This is a manufactured word of recent origin. The root word is "gene" in the sense of a biological unit of inheritance and selection. A meme is a cultural unit of inheritance. There is now a field of study of memes called memetics. Here is a major web site devoted to memes. Go here for some speculations on memetic engineering.

memory  See the special section on memory.

mind  The Indo-European root men, meaning "to think"

mnemonic  Usually refers to a technique for assisting people to remember something. From the Greek mnemon, meaning mindful. The claim has been made that there was a Proto-Indo-European word men that had several meanings, one was "to think". Attempts have been made to also trace the English "memory" via a Germanic path to men. The English word "think" seems related to the Germanic thankon and possibly to an Indo-European word, tong, to think or feel. This is just one of many questionable areas of analysis of word origins that seems contaminated by enthusiastic efforts to link Greek via deep connections (pre-Classical Greek) into other Indo-European languages. The fact remains that Greek is no more closely related to English than it is to any other Indo-European language. Many English words originated with Classical Greek and no deeper links can be found. I suspect that Greek was heavily influenced by Minoan and other "lost" languages of the Eastern Mediterranean, such as Minoan, which was non-Indo-European. The term "Mediterranean" is used to refer to languages of the region that existed before the arrival of Indo-Europeans. There is good evidence for the presence of indigenous people of the Mediterranean all during the last ice age and extending back tens of thousands of years. There is an old root word, ters, meaning "to dry". It seems strange that the name of a sea would be given in terms of the surrounding land, but it is thought that the Proto-Indo-Europeans had no great knowledge of large bodies of water. It would be interesting to know what the indigenous "sea people" of the Aegean called the sea. The English word "sea" seems to go back only to Old English and the time when German tribes moved from the mainland to England. There is a legend that says that the Phoenicians circumnavigated Africa and good evidence that they traded for tin in England. The Greeks had the word"okeanos" which referred to a mythical ocean that surrounded all the land of the Earth. I'd like to know if the nau of the Greek naus (boat) is found outside of a Greek origin. Minoan words for boat and sea? The English word "boat" seems to only go back to the Old English. I'd like to know the Celtic word for boat. skipam, ship? The present Flemish word for boat is Coche, and the Welsh word Cwch meaning boat betrays the Celtic origins from which the Cog derived. From the wild world of the net: the word "Titanic" comes from the Celtic words 'Tita'' meaning ‘really big', and 'nic' meaning 'fuckin’ boat’. Titanic, really big fuckin' boat.

myth  The word "myth" can be defined as referring a story of forgotten origin, usually dealing with the concept of divinity, which seeks to explain or rationalize an important aspect of the world or a society. Myths deal with the relationship of humans to the rest of the world.

(source) Originally myths were not expressed in verbal or written form because language was deemed
inadequate to convey the truth expressed in the story. The myths were enacted, chanted, painted,
costumed, danced, sung and imagined, sometimes in hypnotic or hallucinatory states. In this
manner the creative energies and relationships behind and beneath the natural world were brought
into the conscious realm The myth was believed to not only to tell about but to create a chain from
the metaphysical world to the physical one.

Later in historical time myth becomes connected to and often identified with another Greek concept,
that of legend, which stems from the Greek Legion or Logos [logos] meaning word or
language. Myth then became a written form. And Mythos/Logos is the activity of human
consciousness which translates or transfers the underlying forms and powers from the unconscious
to the conscious, from the dream world to the world of activity.

The production of myths continues in the modern age. The discussion of memory at this web site deals with the issue of how scientific knowledge is transformed into the form of myths that can function efficiently as memetic constructs. 

past
The word "past" is thought to have been derived from the Indo-European word pet, meaning "to spread, to spread-out." A Latin word is pandere,which has the past participle form: passus. Our experience of the past through the agency of memory is all tied up with a kind of "spreading-out" of our memories. Unlike computer memory which can be digitally precise and perfectly reproduced, human physiological memory and cultural memory is imprecise.

perception

plasticity  A term used within modern neuroscience to refer to the ability of the brain to be modified structurally and functionally in response to an animal's interactions with its environment. Thus, brain plasticity is the basis of learning and memory.

present
The word "present" seems to be a compound word based on the Indo-European root word esse, meaning "to be" and the prefix "prae" meaning "in front of".

Proto-Indo-European  A reconstruction of words spoken by the original Asiatic people who spread out and influenced the development of many languages from Europe to India. I will often shorten this to Indo-European, and sometimes use the short forms: PIE and IE.

realism The word "realism" has been used for a long time and has several meanings. The English word "real" may have come to us by way of the Latin word "res", meaning thing. The Indo-European root "rei", in its meaning "possession" or "thing" was probably of very ancient origin. What things can we possess and hold? These are the real things. It is easy to use our minds to imagine things that exist only in out thoughts, and we call such imagined objects "unreal" in the sense that they are not objectively real, being able to be found in the world outside of human thoughts.

In addition to the ways in which we use the word "realism" in everyday conversation (we say, "be realistic") there are special jargonistic meanings of the word within art and philosophy. One use of "realism" within philosophy relates to the important theory of of Ideal Forms that is credited to the Greek philosopher Plato. Plato taught that philosophers should pay less attention to the objects of everyday experience (like the chair you are sitting on) and more attention to "universal principles". There is a philosophical sense in which philosophers are not particularly interested in any particular memories, but they are interested in the general nature of memory. Plato was greatly influenced by men like Socrates who had begun their lives by trying to understand worldly things, the objects of our daily experience. Worldly issues such as the possible atomic composition of matter were of great interest to the Greeks, but men like Socrates realized that they did not have the tools that are required to observe and understand things like atoms. Socrates turned away from the specific details of the world we experience, which in retrospect was a wise choice. The tools required for showing the existence of atoms were still thousands of years in the future. Socrates wisely turned to the study of abstractions, creations of the human mind that are accessible to the study of all philosophers. Plato is credited with the famous analogy of The Cave, in which shadows on the cave wall are likened to our daily human experiences, while an unseen world of Real Objects exist that produce those shadows. A philosopher must try to move beyond the shadows and think his way to an understanding of abstractions, of imagined Ideal Forms that are the "true" reality. This strange mix of idea and reality has had amazing influence on Western Thought for over 2,000 years, and is discussed in more detail in the section of these web pages dealing with philosophy.

Another meaning of the world "realism" centers on the idea that there are natural categories of objects that correspond to the names, the words, that we use to refer to them. This is a meaning of "realism" that can go hand-in-hand with the Platonic doctrine that abstractions should be the objects of study of philosophers. We can imagine that an Ideal Form like The Perfect Circle we can imagine is the prototype for a category of objects, all of the imperfect circles that we find in the world of our everyday experiences.

A third meaning of "realism" centers on the idea that "real" objects have an existence independent of a person who perceives those objects. This contrasts with Idealism.

river  Our word "river" is thought to have been derived from one of the Indo-European words for "cut", the root word rei, meaning to cut in the sense of a river cutting its banks. The Latin word ripa means "that which is cut out by a river". I wonder if the original land of the Indo-Europeans was an arid land where rivers could often go dry, and it made more sense to refer to river channels rather than the water that was only sometimes in a river channel. Look at the surface of Mars.....we can call a dry river valley or a river channel a memory of a previously existing river.

script  A written form of a language. Pictographic, syllabic, and alphabetic are the three main types of symbols or characters in scripts. The word "script" can be traced back to the Indo-European root skeri, which was one of the words for "cut". Early humans would make marks  or cuts on the surfaces of wooden and clay objects in order to mark time or attempt to record events and things. Any given script can be associated with multiple languages and used to form written representations of spoken language. Pictographic characters were the earliest, leading to scripts containing many characters, one for each object or idea that had to be represented. A common innovation was to use a pictograph to represent the sound of the beginning of the spoken word represented by that pictograph. This allowed one pictograph to represent a common syllabic sound in the spoken language which could then be applied to any number of other words. Since many spoken languages have on the order of 8 vowel sounds and 12 common consonant sounds, syllabic scripts with about 100 characters are common, providing a great reduction in the number of symbols from pictographic scripts. Alphabets with around 25 characters are an additional "advance", again lowering the number of symbols to be memorized, but introducing complications of how to represent all of the sounds used in a spoken language. We are familiar with our modern alphabet which includes both vowels and consonants, but the first alphabets were really just simplified syllabic scripts in which the characters usually represented a consonant and a vowel sound, but often the exact vowel sound of the spoken word had to be guessed by recognizing the word.

th xct vwl snd f th spkn wrd hd t b gssd

When the early alphabetic scripts were used to record trade accounts and familiar stories, there was little chance of confusion; the script served as an accounting record for a relatively simple set of known goods or as a mnemonic aid for a story that was well known in the oral tradition of a people. However, these early scripts made it difficult to have the kind of expanding literature we are familiar with in the modern world. The development of a complete alphabet with both consonants and a complete set of vowels seems to have taken place in Western Asia Minor where Greek was spoken. This innovation seems to have combined two linguistic traditions: 1) the semitic alphabetic script of the Phoenicians and 2) the idea of a complete vowel set that was previously known to the Greeks in the Cypro-Minoan script.

serpent  In English, the word "serpent" usually means snake. The Indo-European root word is serp which had two meanings, 1) cycle or hook and 2) to crawl or creep.

snake  Our word "snake" is thought to have originated from an ancient Indo-European word sneg, meaning "creeping thing". This could apply to all reptiles.

synapse

time Our word "time" is thought to have originated from one of the Indo-European root words meaning "to cut". The root word da, meant "to divide". This root word took on the meaning "to make divisions in time" in the form of the German word tidiz. The German word tidan means "to occur in time."

tree The English word tree seems to have come down to us from the Old English treow and the Germanic trewam. The Indo-European root word is deru. Before the English speaking tribes invaded England, the local Celtic people had the term dru-wid, meaning "knower of trees." The word deru had the meaning of "to be firm, solid", so the use of the root deru to refer to trees is probably from the idea of wood being a solid material for building purposes and for tools. In the same way that we still associate "solid" and "true", deru also had a similar meaning of "true". The fact that Indo-European has such a derived source for its word meaning tree and the fact that there are few Indo-European words for specific types of trees, suggests the possibility that these people originated in an arid region.

wisdom  From the Indo-European root word weid, meaning "to see". The Greek word idea is thought to have been derived in the following way: weid to wide to widesya to idea. The Greek word histor meaning, "learned", is also thought to come from weid (see history). The German language had a word wisson, meaning "appearance". Our word "wisdom" thus seems to have originated in "the wisdom of the senses" rather than any more cerebral or rational idea of knowledge. The Sanskrit word Veda, meaning "I have seen, or I know" is also derived from weid, probably through the same word, widtor, that gave rise to the Greek word histor.