Memory as a Source of Knowledge: The Case of an Alzheimer Patient

Few things are more fascinating that the human brain. Throughout history, in all fields of studies, magnificent minds such Plato, Einstein or Mozart have excelled in their respective areas and have demonstrated the wonders the humankind can achieve. But if there is a particular feature from our brain that despite thousands of pages of investigation we are not even close to understand completely is memory. And like most of the important questions, at some point in history has been addressed by philosophy. In this brief article we will explore how can memory be a source of knowledge highlighting different theories from different authors and we will stress the importance of memory taking the example of what happens when we lost our memory faculties due to an illness such as Alzheimer.

When we analyze memory as a source of knowledge we come across immediately with two big problems: 1) what it is “knowledge” and 2) “how we obtain it”? The way you understand the latter will have a significate influence on whether you consider the memory a source of knowledge or not, and in what way.  If we are empiricists, that is to say, we are sceptics on acquiring knowledge through the intellect and we claim that all knowledge comes through the senses our view on memory must necessarily be different to that of the rationalists or sense sceptics, for whom all our knowledge comes from the intellect. To illustrate such differences we will take a look at the views on memory of a reputed empiricist such Locke and the vision on memory by a rationalist such as Descartes.

Starting with Descartes, we cannot explain his account on memory without introducing the concept of the pineal gland and how he understood it worked. The pineal gland or pineal body is a small gland in the middle of the head. It often contains calcifications (“brain sand”) which make it an easily identifiable point of reference in X-ray images of the brain. The pineal gland is attached to the outside of the substance of the brain near the entrance of the canal (“aqueduct of Sylvius”) from the third to the fourth ventricle of the brain.^[1]  Although fairly recent discoveries has been made, before that philosophers and physicians alike could only but speculate on its functions.

        In his “Treatise of Man”, Descartes attempts to describe conceptual models of man, not man as such, and regarded the bodies of such hypothetical men as nothing but machines, whose working could be understand in mechanical terms. He moved away from the scholastic philosophy who would explain”… the reception by the external sense organs of light, sounds, smells, tastes, heat and other such qualities, the imprinting of the ideas of these qualities in the organ of the ‘common’ sense and the imagination, the retention or stamping of these ideas in the memory…,” by referring to the soul.  Certainly, for Descartes, “it is not necessary to conceive of this machine as having any vegetative or sensitive soul or other principle of movement and life, apart from its blood and its spirits, which are agitated by the heat of the fire burning continuously in its heart—a fire which has the same nature as all the fires that occur in inanimate bodies”. It is in that context that the pineal gland has a very important role, since it involved sensation, imagination, bodily movement and what it is important for us: memory.

Descartes' mechanical explanation of memory was as follows. The pores or gaps lying between the tiny fibers of the substance of the brain may become wider as a result of the flow of animal spirits through them. This changes the pattern in which the spirits will later flow through the brain and in this way figures may be “preserved in such a way that the ideas which were previously on the gland can be formed again long afterwards without requiring the presence of the objects to which they correspond. And this is what memory consists in”. This view was further explained in his “The Passions of the Soul”, where he takes the views expressed on the “Treatise of Man” and introduces the concept of the soul. With regards to memory of recollection, we can read: “Thus, when the soul wants to remember something, this volition makes the gland lean first to one side and then to another, thus driving the spirits towards different regions of the n until they come upon the one containing traces left by the object we want to remember. These traces consist simply in the fact that the pores of the brain through which the spirits previously made their way owing to the presence of this object have thereby become more apt than the others to be opened in the same way when the spirits again flow towards them. And so the spirits enter into these pores more easily when they come upon them, thereby producing in the gland that special movement which represents the same object to the soul, and makes it recognize the object as the one it wanted to remember.

The most important thing of all the above is that you can see how he refers to ideas and not perceptions, he does not rely on the senses and memory depends on how the mind recollects from the pineal gland pre-existent ideas. This is because from a rationalist point of view, the memory depends on the interaction between the information received by the subject and that which he already knows. The affects and meaning are, according to this view, fundamental factors in the constructions of memories. They would not therefore be mere copies of ideas or images from the past but an active construction of the subject. This would explain why when asked to some relatives memories of the day of your birth, for instance, each one of them would give you different accounts, each one highlighting one aspect or another. This can also applied to an account of the crime scene on a court case by the different witnesses or whatever different people from a congregation remember from the Gospel readings the previous Sunday.