The routes of memory
Although Paul Simon bestowed the praises of its slower sibs, I was a devotee of Ektachrome, way back in the day. The time of life in which there are children to photograph drove my transition to print film and, up until then, I had amassed a collection of more than 7,000 slides. These sat for 35 years; in closets in Indiana, in an attic in Pennsylvania, and now in a basement in Vermont. About a year ago I admitted that something needed to be done, for if I did nothing the collection might get lost or discarded, perhaps after I was gone, or it would deteriorate to the point where individual images could not be resuscitated. Using an Epson V500 I have, to date, scanned 4905 images. I hope to be done before spring. I have enjoyed looking at the images, as they are processed, and do not remember having taken many of them. There are a very few, however, which I do remember. Clearly. Especially the one below, taken more than 25 years ago. You may not like the way I’ve presented it but that way was intended to show what my memory of the experience is like, in my head, now. I have discussed this fascinating topic of memory before and thought about how a simple image may evoke experiences of long ago. I like to think about how sensory input can influence neural circuits. It’s not so much the neurons themselves, but stimulation of the connections between and among them, which may create the response we call memory. I imagine that when I originally experienced the moment at the beach, tens if not hundreds-of-thousands of neurons had been stimulated. Visual neurons, auditory neurons, perhaps even neurons that responded to temperature, touch, and taste. My point is that the very specific experience may be characterized by the summation of all of these modality inputs and their influence on my brain. That influence must be characterized by the very specific pathways taken by the inputs and the ensuing connections made between and among neurons as information made its way to higher processing centers. It is, perhaps, the pattern of information flow which forms the experience, and, by extension, the memory. So, when an image from the past is presented, those same neural paths, those connections, are somehow stimulated once again and the memory resolves into consciousness. Does it bother you that I have suggested a neurophysiological basis for memory? How could it be otherwise? Would you have preferred that I argue for the action of some ineffable, unknowable, agent? No, I believe that explaining memory as a side-consequence of the neural substrate of the brain is much more satisfactory.