Hofstadter, Dennett - The Mind's I

A Conversation with Einstein’s Brain 437of our hypothetical mind-brain encounter; every boat leaves a disturbance behindit, its wake, as it travels through its medium. The `hot spot' within the brain, justlike the boat, leaves its own kind of disturbance, or wake, behind: the neurons thatjust fired as the signal came through continue to undergo some kind of internalactivity perhaps chemical in nature-for a few seconds. A permanent change in theneuron is thereby effected. The change is reflected in some of the numbers wehave already spoken of, such as the threshold value for firing, the axonresistances, and so forth. The exact way in which those numbers are modified is,of course, dependent on certain aspects of the internal structure in question-andthese aspects themselves are susceptible to numerical encoding." I might wellchime in at this point, I imagine, saying "Hence it would be of utmost importanceto record those numbers for every neuron, as well as the already-mentionedresistances and thresholds." You would no doubt reply, "An astute remark,Achilles; I had not anticipated you'd see that necessity so quickly. And we mightdo well to give those numbers a name too: the 'structure-altering numbers' seemsadequate to me." To conclude this exchange, I might make the following sort ofremark: "The structure-altering numbers are quite remarkable in that they not onlydescribe how other numbers on the page are to change, but also how theythemselves are to change, next time the neural flash comes passing through!"TORTOISE: Oh, you have captured quite well the essence of what might go on betweenthe two of us in an admittedly hypothetical dialogue. I might well say all thewords you attributed to me; and I have every reason to believe that you too couldcome forth with such utterances as you have just proposed. Thus, what have wecome to? Ah, yes, I recall-in the hypothetical situation set up, I was in possessionof a book, wherein were numerically recorded all the relevant data, neuron byneuron, taken from the brain of Albert Einstein the day of his death. On eachpage, we have: (1) a threshold value; (2) a set of page numbers, to indicateneurons linked to the present one; (3) the values of resistance of the linking axons;and (4) a set of numbers indicating how the wakelike "reverberations" of theneuron, which occur as a result of its firing, will alter any of the numbers on thepage.ACHILLES: By telling me what you have just said, you would have completed your aimof explaining to me the nature of the heavy tome in your possession. So we wouldprobably have come to the end of our hypothetical dialogue, and I can imaginethat we would soon