Memory: The Link Between Past and Future
What is the Point of Memory?
Memory has evolved, no doubt, because it is a benefit to survival. This is quite clearly evident in many different ways: We remember where food is; we remember who is a friend and who is a foe; we remember details; we remember stories and narratives that give us place and culture; we remember fears; and we remember pleasures. We remember many things to help us be safer and more successful in the future. I say “the future” because that is what memory is all about—holding the experience of the present in such a way that it can be useful in the future.
Colloquially, we say that we “learn from our experience”. This actually means that memory is not just a benign storing of information, but a resource that can be accessed; it is something that is encoded, stored, and then retrieved (Baddeley, Eyesenck, & Anderson, 2009). What occurs in the present is encoded by biological processes and stored somewhere. This recording of the present soon becomes an artefact of the past but, once retrieved, returns to the present again. Memory is something of a time machine. It is a link between what was and what might be. Memory can—and does—influence what we will do in the next moment.
Memory is a powerful thing.
The Way We Live
Our behaviour, our responses, our actions, are affected by a number of inbuilt qualities and quantities that we bring with us into this world as the building blocks of our ongoing development, or nature. Many things contribute to our “nature”, including: instinct (Winston, 2003); temperament (Kagan & Snidman, 2004); evolutionary genetic “hardwired” patterns (Watson & Crick, 1953); gene mutations and polymorphisms (Bull, 2000); neural architecture (Oschner & Gross, 2007); and immediate levels of demand by the inner and outer environment (Lovallo, 2005). How these elements function together is a product of one more vital element: ongoing experience (Narvaez, Panksepp, Schore, & Gleason, 2013).
We enter this world with all these elements ready and able to develop in response to experience (the nurturing of our potential), and to allow the individual that each of us eventually becomes to emerge. Each individual is an extraordinary symphony, unique in melody, tone and key, even though we all use, pretty much, the same instruments. Each life is a unique expression of the complex interplay of nature and nurture. We live and learn—and remember (Kandel, 2006).
A Multitude of Memories
We generally think of memory as a neurological process, and this is usually how we experience it, in our thoughts. Nevertheless, memory is a ubiquitous quality that manifests in many places and many ways throughout our biology.
Some memory is explicit, in our conscious, reflective awareness. This kind of memory is mostly brain-based and comes to us as facts, details, stories, images, sounds and smells, in such a way that we are able to think about the memory and consider how best to utilise it. But much of our memory is implicit, beneath our conscious awareness, when we find ourselves acting out behaviours and emotions and feelings, even when we don’t really know why we are doing that action, or feeling that emotion (Schacter, 1987). This is a fundamental issue in therapy: We often need to help clients bring memories that are implicit into the explicit, where they can employ conscious thinking to bring about a beneficial effect. Implicit memory is stored in various brain areas such as the amygdala (fears and emotion), the striatum (habituated thoughts and behaviours), as well as the cerebellum (automatic procedural actions) and fusiform gyrus (face recognition), all as described by Squire (2004). But there is much more.
Neuronal circuits are just one form of memory—what we might think of as a macroscopic form of memory. There is much going on at the microscopic, molecular level too. For example, one of our most important biological memories are the “antibodies” developed by our adaptive immune systems as a memory of the bacteria and viruses that we encounter along the way. Then the next time that pathogen invades our body we are ready for it—we remember it—and we are protected (Agerberth & Gudmundsson, 2006).
One of the most fascinating forms of memory, and one which has become a hot topic in the past decade, is the epigenetic process whereby biochemical markers are written directly onto DNA structure for the specific purpose of altering the way in which genes are expressed. These alterations are “tweaks” that an individual organism makes in response to experience, in the anticipation that that experience will occur again, in preparation for the future.
It is easy to forget that gene expression is the first step in everything that happens in our biology. It is through gene expression that the proteins—the building blocks of all our biological matter—are created. Thus, when we talk about neurotransmitters like serotonin and dopamine, or peptide hormones like oxytocin and corticotrophin-releasing hormone (CRH), we are in fact talking about bio-chemicals that are created through the stimulation of gene expression. Equally important are the receptors for these neurotransmitter and peptide hormones, which are also created by gene expression. Our biology essentially functions through the interplay of these chemicals and their receptors (Lodish et al, 2000). Nevertheless, although epigenetic processes are needed to alter the balance and flow of that interplay (in response to a present experience), so that we are better prepared for future experience, epigenetics is just the tip of an iceberg of a multitude of memories.
Understanding that we constantly prepare ourselves (in advance of experience) through a number of memory systems can help us deliver better and more effective therapeutic interventions. One of the many fascinating new discussions about how we can affect memory—in addition to established knowledge of things like Pavlovian conditioning and memory extinction, and the opposite concerns of amnesia and aphasia—is memory reconsolidation. For the most part, therapy has looked to behaviour to provide the insight into what is going on with our client; now, however, the modern neuropsychotherapist will be able to—indeed, will need to—look deeper, understand more, and seek to effect change on many more levels of human functioning.
I hope we will remember that.
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Baddeley, A., Eyesenck, M. W., & Anderson, M. C. (2009). Memory. Oxford: Psychology Press.
Kagan, J., & Snidman, N. C. (2004). The Long Shadow of Temperament. Cambridge, MA: Harvard University Press.
Kandel, E. R. (2006). In Search of Memory: the emergence of a new science of mind. New York: W.W. Norton.
Lodish, H., Berk, A., Zipursky, S. L., Matsudaira, P., Baltimore, D., & Darnel, J. (2000). Molecular Cell Biology (4th ed.). New York: W. H. Freeman. Retrieved from http://www.ncbi.nlm.nih.gov/books/NBK21475/
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Oschner, K. N., & Gross, J. J. (2007). The neural architecture of emotional regulation. In J. J. Gross (Ed.), Handbook of Emotion Regulation (pp. 87-109). New York: Guilford Press.
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Watson, J. D., & Crick, F. H. C. (1953). Genetical Implications of the structure of Deoxyribonucleic Acid. Nature 171, 964-967.
Winston, R. (2003). Human Instinct: How our primeval impulses shape our modern lives. New York: Bantam Publishing.