Association is at the root of all types of learning, even the simplest. Without the association between things already known present in the memory and the comparison with new experiences, human thought would not be possible.
Consider the conditioned reflex : it is a very simple and automatic response not only for humans, but also for a large part of the animal kingdom. From our point of view “something new” enters in the reign of “already known”. Two different facts like a bell ringing and food being available create a link between them for the simple fact that they happen one after the other. The most important function that association fulfils is to bring the unknown into the domain of the known. It is a powerful ability of our mind, it is pervasive and seldom we are aware of its extent. I repeat it, but the concept must be clear: not all thoughts can be reduced to the concept of association, but association is at the basis of all forms of thought and memory. Consequently, creating new and suitable associations strengthen memory.
Bringing the “unknown” into the "container" of the “known”
The strategy is always to connect new things to others already known; or insert new information in a group, or in a category already well defined for us. This is basically what all dictionaries do: define particular things with concepts or more general words with the meaning presumably already known to the reader. The more particular the meaning that we attribute to things (i.e. specific and well defined in detail) and subjective (i.e. emotionally significant for us), the greater the grip on the memory that we will get. The same reasoning can be done to sequences of letters that do not form any word. If we extend the reasoning by individual entries in speeches (or theories) incomprehensible to us, the issue becomes more complicated, because the memory cannot “understand” in the place of the intellect, although the principle of memorization remains the same.
Assign meaning to any new information
Not always does the information we receive have a full meaning, or it has one so abstract that it (the meaning) does not mean hardly anything definite; as happens for numbers when they are considered only for themselves. What's the mnemonic-eidetic value of 2543 if not the repetition of an imagined unit (as could be the representation of an apple) 2543 times. While representing the number with apples, we could hardly get the precise image of a set of 2543 fruits. In all the cases in which a meaning of a new word is unknown, or difficult to be traced directly to an image, it is necessary to rework the knowledge that we want to acquire semantically and iconographically in order to make it more familiar. For example, 2543 could be the password to my computer; an alternative might be to divide the irrelevant set of digits into meaningful segments: 25, as the house number of the street where I live, and 43 the number of stairs in my building. A similar strategy can be used to remember a set of letters that doesn’t form any possible word, or to memorize an acronym: we need to divide the letters into significant segments of letters to which can attribute a meaning with imagination.
Mnemonics and dynamic mental scheme
One mistake that many people make is to believe that mnemonics are methods for remembering things. This is only partly true; to be precise (but it is a necessary clarification) the mnemonics do not aim directly at the memory, but to building a mental order in which we can remember things. So the direct and primary objective is not the memory, but the order – and not a static order, but a dynamic one. Only in this way can the secondary objective be achieved, which is precisely the memorization; but it is a ‘secondary’ result only in the sense that, if we get the first, accordingly the second follows almost naturally. If the mnemonics (and memory as a whole) are more dependent on the order than of the imagination, it is an old issue and it will always remain without a definitive solution. Nevertheless, we can say that the adjective "dynamic" attributed to the noun "order" goes, at least, to mediate the two opposing factions (the one that sees in the imagination the mainstay of the memory and the other which instead attributes the mainstay to the order); because I mean the adjective “dynamic” as the element that can change some characteristics of the subject “order”. A factor which can be structured in consideration of the imagination and of its phenomenology.
The order is the sequence, the network and the constellation of associations
The correct order, however, is guaranteed by the correct sequence of associations. So, from my point of view, the contrast between order and imagination is a false question and it depends on the learning style of each individual to give more importance to one element rather than the other. Imagination and order don’t mean anything separately: imagination always produces a chain of associations between images, therefore it always produces an order. It is obvious that not all orders are equal: there are chains of associations of images and concepts that are more functional than others to memorization. But imagination is always something organized, otherwise it would be nothing. Those who give more importance to imagination do not realize that it is always and immediately organized; the others that believe that the order is more important fail to see the order in the imagination. They abstract and transfer on a theoretical level some provisions and features that are exclusively theirs. Indeed, the order is the sequence, the network and the constellation of associations.
In the history of philosophy and psychology there have been many schools of thought that saw in “the association of ideas” the element able to explain all human thinking. This was all in all a rather superficial way of understanding things and now no one believes that human thinking can be reduced to a simple chain of thoughts. However the importance of the association as a psychological phenomenon goes beyond the philosophical theories that have been built above it. The psychological process of association is crucial to the functioning of human thought and – with regard to the purposes of mnemonics – it cannot be reduced to other phenomena nor split into even more elementary processes.
One way, but not the only, in which we can understand the association process is like the ‘shift’ of an image from one place to another, such as the transit of an image, or a set of images, by representations that contain it/them to others that “will contain it/them”. Association and dissociation considered then as an approach or moving away of images with each other in a given context. This is an important element that we must take into account in order to understand figures of speech well (metaphor, metonymy, synecdoche etc.) which are also figures of thought. Associate means to relate things, concepts, images or parts of them. What is the significance of association of the colour green to a sweater? Obviously I attribute the green to the sweater. The association, therefore, may also be related to only a part (however small) that allows my mind to relate, giving similarity to two different things. So, I can associate two sweaters through the green colour even if only one of them has only one green line while the other is completely green. The association in this case is by similarity, that is, for partial identity; but in other cases we can establish other types of association.
Some types of associations are only conventional, i.e. there are no elements that the imagination can naturally “put near”. In these cases, that is when the bond between the things is conventional, our mind performs an effort of abstraction. The rule is: the more a link is conventional the more it is abstract. We make more effort to tie a thing that is concrete, sensible, perceptible to an abstract one than connect two material objects. This is a general rule that can be circumvented in some cases with mnemonic strategies, but it is a principle that has to be always taken into account when we make connections between thoughts. To understand how important it is to avoid making forced associations between concepts, ideas and images, we must pay close attention to what types of connections to use and how to use them. The criterion of the associations defines the order of the mental representations and these last determine the organization of our knowledge. So in the next article we will analyze the fundamental criteria of mental associations.
 For this article the referring text is a work that I published in italian: Paolo Fabiani, Metafora e memoria - Strutture semantiche e processi di apprendimento, memorizzazione e studio, Libri liberi, Florence, 2015.
 In a series of experiments in 1907, Pavlov associated the administration of food in laboratory dogs with some stimuli, such as lights and bell sounds. He shows that after repeated events in which the administration of food was associated with the sound of the bell, he has obtained the salivating of the dog with just the manifestation of the sound of the bell, without administering food. Salivation which originally was a response to the food vision became a reaction to the sound of the bell. The dog had learned to respond to the sound of the bell as if it was the presence of food.