It is, unfortunately, a necessity when discussing items of a scientific nature to define certain technical words/phrases that are, let’s face it, going to come up more than once in the upcoming text. In an effort to reduce the clutter of jargon, and quite frankly because I will tire of writing the words, I have assigned several of the more commonly used terms their own Three-Letter-Acronyms (TLAs). Below is a comprehensive list of TLAs and definitions that are necessary, though perhaps not sufficient, for comprehension of the following text, which should be referred to when appropriate:
***
EPI =Episodic Memory: narrative memories, or memories that possess a where, what and when.
HIP =Hippocampus: sea-horse shaped body of neurons central to Episodic Memory.
CTX = Cortex: the great majority of the mammalian brain, responsible for higher cognitive function.
DBD = Degenerative Brain Disorders: disorders that degrade the neural machinery and cognitive functions that this machinery supports.
***
Though often perceived as robotic automatons, scientists are, when you come right down to it, people. They rely on the same basic structures and functions of daily human life. They eat, they talk, they share stories, and sometimes, they even gossip. There even exist chance occurrences when they do all of the above. This is the story of one such occasion1 in the lab of someone we’ll refer to as Dr. Memoryman,2 expert on memory, and generally acknowledged all-around mensch.
Let’s set the stage. Gathered around the table is a small collection of brain scientists, the master and his apprentices, collectively engaged in what one might generously term “small talk.” What starts as banal banter quickly ascends into the heady territory of Dr. Mem’s own personal philosophical foundations as he, DMM3 himself, begins to relay the story of a sweet old woman who recently contacted him with questions about human memory, which seems apropos given his nom de guerre.
This woman and her story would catalyze the opening of what was for those present a window into the mind of genius. This will take some setup and background knowledge to comprehend in a manner befitting its importance.
The story essentially plays out as follows. A few years ago, the woman came into the great fortune of having her first grandson, seemingly healthy &c. It turns out, however, that the appearance of health was merely that. This grandson, now four years old, was born without a hippocampus (hereafter referred to by its TLA), a vital brain structure required for the formation and reclamation of long-term memories. And so this poor child, this HIPless Grandson, requires nearly constant supervision as he lacks the ability to learn anything aside from basic motor tasks. Naturally perturbed by this series of events, this loving and intrepid Grandmother turned to the scientific literature in an attempt to learn anything she could about human memory in the hope that something could be done to aid her HIPless Grandson. Inevitably, she stumbled upon the name of DMM, aforementioned pioneer of memory research, and reached out personally to ask if there was anything he could do. The answer was, very unfortunately, no.4
As is the want of brain scientists, those present began to hypothesize about the presumptive inner experience of the HIPless Grandson. The question arose, “What must it be like to live your entire life without a HIP?” Of course, any halfway credible answer to this question requires some knowledge of what the HIP does and how it works.
**Interpolation **
DMM is only one of many intrepid researchers currently exploring how memories are created and stored within animal and human brains. As a group, these researchers have discovered many basic elements that are worth reviewing. First, that the HIP is necessary for the creation of new memories. Second, that the HIP is not in-and-of-itself sufficient for memory creation and storage, which also requires the HIP to interact with the CTX. Third, and perhaps most importantly, that neurons in the HIP and CTX don’t fire all alone, but instead fire in packs, grouped together in rhythms of different frequency. These different rhythms partition off subgroups of neurons in the HIP and the CTX that share information with each other. This isn’t trivial stuff. These rhythms seem to be fundamental to the mechanisms underlying memory trace consolidation; the process through which information coming from the CTX modifies networks of neurons in the HIP, or to put it another way, this is how we create and bind memories. These neurons in the HIP store the pathways and connections that link the different elements of events and episodes together. When these self-same networks of cells in the CTX are shocked back into activity by bursts of electricity coming out of the HIP, it reactivates the memories that are (in some sense) stored therein.
Reactivating this network of neurons in the CTX enhances the strength of the connections between the original batch of neurons that stored the memory, increasing the likelihood that a new burst of activity from the HIP will excite this whole batch again, making the whole thing one iterative infinite regress. The unfolding of which slowly constructs these things that we call ‘stable long-term memories.’ These memories are of a specific flavor, EPI memories. They are narrative memories, that take place in space and time, which it should be noted is very different than the flavor of memory that supports learning simple motor tasks, like walking, or remembering simple facts about your world, such as the fact that EPI memories take place in space and time.5 People who have damaged HIPs, either from external brain damage or DBDs, are, to put it mildly, significantly impaired. Many lose EPI memories that haven’t completed the transition to ‘stable long-term memories’, and, as if that wasn’t enough, they also lose the ability to form new EPI memories, which one can imagine is crippling in all sorts of ways.
**End of Interpolation**
And so in response to this question (see above), DMM extrapolates what he thinks lies at the very center of human experience: that we create a ‘self’ through a process of continuous personal narrative.6 And that the process by which we construct this narrative is the same process by which we construct our EPI memories. At that very lunch table, DMM makes the not-so-obvious leap that these same brain areas and these same mechanisms are the basis of our most persistent illusion: our selves.7 That in essence, for the HIPless Grandson, it is unlikely that there has ever been any recognition of self.
What struck those present as particularly significant about this statement wasn’t the nearly unimaginable nature of a human being without self-recognition, though to be honest that seems significant. What struck them was that in the end, our precious selves boil down to little more than a collection of patterns, formed and reformed by a continuous dynamic process. And that the set of points in the process where these patterns can be corrupted reaches numbers that for all practical purposes can be treated as infinite. And that as the infinite enters, assigning low probabilities to events (specifically the probability of corruption) ceases to mean much of anything. Leading one to doubt very much the fidelity of any beliefs or memories one might currently be entertaining, or truthfully the very purpose of leaving one’s perfectly comfortable bed, as the only thing that can be trusted to be semi-believable is the incoming information in this moment that has yet to be warped and transmuted by this process. And to be quite honest, that information is leading yours truly to think that perhaps it would be easier to just go back to sleep where none of this existential angst matters much.8
It’s pretty much unnecessary to point out that those assembled remained nearly silent for the rest of the lunch, as all involved contemplated what it truly meant ‘to be.’ Of course, humans have been contemplating this question for centuries. And we’ve told ourselves millions of stories in an attempt to try to explain it to ourselves and to others. It’s doubtful that any of these stories are correct, but in essence, it doesn’t matter. Telling the stories is what matters. Telling stories is the only thing that matters.
1. With the omission of gossip. ↩
2. Real names have been omitted due to various minutiae that are neither very interesting, nor very relevant to the narrative hereafter. ↩
3. The author wishes to apologize for introducing yet another TLA that the reader must remember throughout the piece, though the author also suggests that since the subject of the piece is itself memory, there is some meta-objective serviced in forcing the reader to engage with his-or-her own. ↩
4. The author wishes to clarify that this perfunctory answer is not meant to be a flippant dismissal of the dire desires of the sweet old woman to help her HIPless grandson, which are tragic and heart-tugging &c., but instead is a brutally realistic assessment of the nascent state of human neuroscience, which is, to be honest, in it’s own toddling stages. ↩
5. Or the myriad TLA’s that your author has asked you to remember for the duration of this narrative.↩
6. As a point of fact, the very structure of this narrative (and by this I mean this one that you are reading) can be considered a form of ‘self’-creation, with the ‘self’ here being some amalgamation of me, your author, and the inimitable DFW himself. ↩
7. The author should point out here that this point remains controversial, and requires the accrual of a significant pile of evidence before one can state it with anything other than obfuscating equivocation. Which, of course, the intelligent reader would have discerned is precisely the function that this footnote serves.↩
8. Although, of course, the very chain of thoughts that led yours truly to these conclusions can hardly be trusted for the very same reasons as mentioned above, which realization, surprisingly, does little to lessen said angst. ↩
[Inspired by the inimitable David Foster Wallace]
Alex studied computational visual neuroscience at NYU and received his Ph.D. in the spring of 2018. He now works at Apple.