backyard brains

I’m going to make a con­fes­sion, get some­thing off my chest that has gnawed at my con­science for many years (ok, just the occa­sion­al pang these days, but still).  Elec­tro­phys­i­ol­o­gy was a bit of an obses­sion for me as a kid, though I didn’t know the word.  Cer­tain small mam­mals were dis­sect­ed on our din­ing room table around age 7–9, and the “gal­van­ic exper­i­ment”— using bat­ter­ies to make recent­ly dis­em­bod­ied mus­cles twitch— was a big thrill.  Then I became fix­at­ed on doing the oppo­site— mea­sur­ing sig­nals elec­tron­i­cal­ly from liv­ing sen­so­ry recep­tors.  But how to do it?  There were some attempts, includ­ing a rather grue­some one with a gar­den lizard’s head, all fail­ures.

One evening, I over­heard an adult say­ing some­thing sage about the extra­or­di­nary sen­si­tiv­i­ty of cat whiskers, how they can “see” in the dark with them.  (It turns out this is true for rats, but not for cats, whose whiskers are about as use­ful as ours.)  I imag­ined some kind of mys­te­ri­ous action at a dis­tance, an elec­tro­sta­t­ic effect maybe, and sly­ly shift­ed my gaze under the table, where our very sweet Siamese was curled into a ball of unsus­pect­ing mono­chrome fur, nap­ping.  I picked him up, took him into my bed­room, closed the door, snipped off a whisker, then began pok­ing at it with alli­ga­tor clips, try­ing to get a sig­nal on my mul­ti­me­ter as I waved it around the room.  Noth­ing.  Per­haps whiskers only respond to con­duc­tors, or only at very close range?  Still noth­ing.  Of course, because I need­ed to instru­ment the bulb at the root of the whisker, where the nerves would be!  It would have to be care­ful­ly pulled out then, not just cut.

Until this point, the cat had been fol­low­ing my antics with only mild con­cern, but the whisker-pulling was going too far.  Was I an autis­tic child, unable to empathize with my des­per­ate­ly strug­gling pet, who also hap­pened to be my favorite and most loy­al com­pan­ion?  I wish I could say that I was, but I think not.  I knew this would hurt.  It hurts to pull out hair, and a whisker is a lot thick­er and more deeply bed­ded.  But in my excite­ment to mea­sure an elec­tri­cal response I felt that the cat’s objec­tions took a back­seat to the high­er aims of our project.  We were col­lab­o­ra­tors, he and I, and knowl­edge car­ries a price.  One of my ear­li­er attempts had involved cut­ting off a lit­tle flap of skin from my own knee and try­ing to record touch, hot and cold sen­sa­tions from it (unsuc­cess­ful, but could be passed off lat­er as an acci­den­tal­ly skinned knee).  Now that I think about it, it’s curi­ous, the way I don’t remem­ber feel­ing any pain from the knee exper­i­ment at the time, fix­at­ed as I was on the out­come.  Sort of like not laugh­ing when you tick­le your­self.

It’s a pity, adages notwith­stand­ing, that the cat didn’t share my curios­i­ty and its anes­thet­ic qual­i­ties.  Because now I need to relate the most damn­ing part of the sto­ry.  I was per­sis­tent.  I thought I might need to vary my record­ing tech­nique.  I thought some whiskers might be much more sen­si­tive than oth­ers.  I thought per­haps a whisker’s mag­ic prop­er­ties didn’t sur­vive long in the open air.  In short, I believed in try­ing again.  And dear read­er, I did.  I tried until there were no whiskers left.

The cat for­gave me even­tu­al­ly.  Whisker­ton was a heart­break­ing­ly for­giv­ing ani­mal.

*    *    *

Fif­teen years lat­er, Adri­enne and I were doing pret­ty much the same thing in Bill Bialek’s lab, stick­ing elec­trodes into fly brains and record­ing neur­al spikes.  That was a beau­ti­ful and clas­sic exper­i­ment.  The fly was immo­bi­lized in a blob of wax, watch­ing an oscil­lo­scope screen with mov­ing bar pat­terns, with a lit­tle cup under its pro­boscis full of sug­ar water to keep it alive.  Think “A Clock­work Orange”.  The elec­trode was in one of the large stereo­typed neu­rons com­mon to all flies, H1, which encodes wide-field hor­i­zon­tal motion.  It’s diode-like, emit­ting a flur­ry of spikes when the world moves in one direc­tion, remain­ing silent when it moves in the oth­er.  There’s a “left” and “right” H1.  You could tell when you had the right neu­ron by plug­ging the elec­trode ampli­fi­er into a speak­er and lis­ten­ing for the clicks.  Wave your hand in front of the fly in one direc­tion, and it sound­ed like a Geiger counter over Cher­nobyl milk.  In the oth­er direc­tion, noth­ing.

The flies lived about as long plugged into this appa­ra­tus as they would have in the wild.  You could record from them day after day.  Adri­enne and her lab­mates for some rea­son thought it com­pas­sion­ate to go into the lab and drop­per some more sug­ar water into the cup on Fri­day night, even if the fly was unlike­ly to make it through the week­end.  It’s curi­ous, how an ani­mal one wouldn’t think twice about swat­ting into a Rorschach blot becomes an object of empa­thy when one has spent an hour embalm­ing it in can­dle wax and care­ful­ly pok­ing a wire into its brain.

*    *    *

Anselm and Eliot are sweet­er chil­dren than I was, for sure.  Anselm was intrigued but a bit hes­i­tant about the Back­yard Brains kit he got for Christ­mas.  Yes, a pair of rogue neu­ro­sci­en­tists have done it— they’ve made an inex­pen­sive mail-order ampli­fi­er so that kids can record neur­al spikes at home.  No, this isn’t a New York­er car­toon.  You can buy it assem­bled or just get the raw cir­cuit board and DIY.  (Should have done that, Anselm’s almost 9 and I think it’s time for him to learn to sol­der.)  There’s a small speak­er built in, or you can hook the amp up to your iPhone and make an oscil­lo­scope.  (!)  Mail-order cock­roach­es are extra.  The won­der­ful hand­writ­ten man­u­al cheer­i­ly notes that the cock­roach will be “just fine” after you snip off a leg, and adds that it’s a good idea to dab Vase­line on to pre­vent it from dry­ing out (the leg first, then the stump).

We didn’t order the cock­roach­es.  Even­tu­al­ly Anselm found a dying bee­tle out­side wav­ing its legs in the air, so this seemed like fair game.  I had to do the snip­ping.  With the elec­trodes in the leg, we were get­ting quite a bit of noise in the record­ing, but it looked like there were spikes in there.  The chat­ter seemed to increase when we rubbed the lit­tle hairs on the leg.  We tried apply­ing cur­rent too, and were grat­i­fied by a Franken­stein­ish gal­van­ic mus­cle twitch.  Well, I was very grat­i­fied, and Anselm was most­ly grat­i­fied.  His curios­i­ty and his almost eeri­ly intense eth­i­cal sense were clear­ly in con­flict.  There was a cer­tain ick fac­tor.

Lat­er that evening, we had a long con­ver­sa­tion about whether insects have feel­ings, how they might expe­ri­ence pain, and whether a lin­ger­ing death on the side­walk or a quick one at the kitchen table would be prefer­able, before rang­ing more broad­ly into the hin­ter­lands of bioethics.

The five-legged bee­tle spent its last earth­ly hours bel­ly to the heav­ens in our gar­den.

What is the nat­ur­al state of a child’s ethics?  Is this 19^th cen­tu­ry ques­tion even mean­ing­ful with­out social con­text?  I remem­ber plen­ty of vio­lence and bul­ly­ing on the play­ground, a lot of squashed bugs and frog dis­sec­tion antics.  Anselm and his class­mates are a lot more civ­i­lized— per­haps at some lev­el more civ­i­lized than I am at 35.  This seems hope­ful with respect to, say, avoid­ance of future geno­cides.  Then again, are sen­si­tiv­i­ty and squea­mish­ness the same thing?  Is it good to be afraid of worms, or to not know whether a snake’s skin is wet or dry?  In Mark Twain’s Mis­sis­sip­pi, chil­dren trad­ed stiff-limbed dead cats for mar­bles.  They also wit­nessed lynch­ings.  Roald Dahl thought noth­ing of putting a dead mouse in his pock­et; but he got a thor­ough can­ing for the sub­se­quent use of it.  Today the kids use a pen­cil eras­er to turn over a dead grasshop­per, and spank­ing is more or less con­sid­ered child abuse.

Acci­dent or design?  The cou­pling in our heads of the “ick” response, which seems suit­ed most­ly for avoid­ing taint­ed food, with the empath­ic shud­der, which seems fun­da­men­tal­ly about the­o­ry of mind and the avoid­ance of pain in oth­ers, seems to me like one of the odd­er hacks in our evo­lu­tion.  Per­haps it was once a design short­cut, like Volkswagen’s spare-tire-pow­ered wind­shield wash­er.

As we civ­i­lize our­selves, this curi­ous acci­dent seems to be simul­ta­ne­ous­ly bring­ing us clos­er to each oth­er as sen­tient beings, and fur­ther away from the nat­ur­al world, from the embod­ied in all its elec­tro­phys­i­o­log­i­cal messi­ness.