Bloomberg Businessweek - USA (2019-06-24)

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June 24, 2019

A screendisplaysa greenpathwaywith

a bluerectangleattheend.Asthemouse

beginstoruninplace,tryingtoapproach

thebluerectangle,it muststeercare-

fullytostayonthevirtualpathway.Like

humans,themicetakeona glassy-eyed

castastheyplay.Thesessionslastabout

a half-hourbeforetheyloseinterest.

Themicroscopespeeringintotheir

brainsrecord anincredible amount

ofinformation.“Wecan covermost

alloftheirsensory,motorcortex,and

decision-makingareasatthesametime,”

Mathissays.Theresearcherssometimes

changethegames’rulesandcontrols—

for instance, by making joystick pulls

result in zigzag motions instead of

straight ones—then look for differences

in how the neurons light up. Mathis has

also been working to shut off subsets of

neurons, such as the nodes associated

with learning, to check how the remain-

ing ones react. One early insight: When

it comes to decoding motion, the sen-

sory cortex seems to play a larger role,

alongside the motor cortex, than previ-

ously thought. “These neurons are doing

a lot more than engaging in one specific

thing,” she says.

One of her primary motivations is to

learn more about how animals rapidly

adjust to changes in their physical envi-

ronment. When you pick up an object

of unknown weight, for example, your

brain and body quickly compute what

kindofforceisneededtodealwith

it.Robotscan’tcurrentlydothat,but

oneinfusedwiththeneuronallearn-

ingpatternsof a mousepotentially

could.Miceareanunusuallystrong

candidate tohelp bridge the gap,

Mathissays.Theirbrainsarecomplex

enough to demonstrate high-level

decision-makingbutsimpleenough

fortheresearcherstodeducethecon-

nectionsgivenenoughtime.

We’veonlyrelativelyrecentlydevel-

opedcomputerspowerfulenoughto

capture,process,andanalyzethevol-

umeofdataproducedbya subsetofthe

averagemousebrain’sroughly 75 mil-

lionneurons.Andit’sonlywithinthe

lastcoupleofyearsthatAIsoftwarehas

advancedfarenoughtoautomatemuch

oftheresearch.Mathisandherhusband,

AlexMathis,a fellowneuroscientist,

havedevelopedopensourcesoftware

calledDeepLabCuttotracktheirsub-

jects’movements.Theapplicationuses

imagerecognitiontofollowa mouse’s

tinydigitsasit playsa gameandtrack

itsreactiontothesugar-waterreward.

Scientistsusedtodothistypeofwork

manually,jottingdown everysip of

waterintheirnotebooks.Thesoftware

nowperformsinminutestasksthatonce

requiredweeks’ormonths’worthof

attentivehumanlabor.“There’sa paper

onprimatesfrom 2015 wheretheytrack

quitea fewbodyparts,likeknucklesand

limbsandonearm,andthemonkeyhas

differenttasks,likereachingforthings

andholdingthem,”Alexsays.“Thefirst

authorofthepaperwrotemeandsaid

hisPh.D.couldhavebeentwoyears

shorter.”Morethan 200 researchcen-

tersnowuseDeepLabCuttofollowall

mannerofanimals.

Thistypeofsoftwaredevelopment

andanalysisattractstechcompaniesto

neuroscientistsjustasstronglyastheir

insightsaboutanimalcognition.The

modernbrainresearcherhastoknow

howto codeandworkwithincred-

iblevolumes ofinformation, much

asan AIstafferat Google wouldto

improveanadvertisingalgorithmorthe

lane-mergingabilitiesofa self-driving

car.Animal-centric neuroscientists

are also accustomed to working with

unconventional ideas. “You tend to get

creative people that are a little bit cow-

boy,” Mackenzie says. “People who are

willing to bet their career on trying to

study a black box.”

TimOtchydoesn’tdomice.He’sa bird

man.A researchassistantprofessorat

BostonUniversity,Otchysportsatattoo

of a zebra finch on his right forearm.

It shows the short, squat bird with a

bright orange beak sitting on a branch

and gazing pensively at the sky. “I do

really like birds,” he says, sitting in an

office filled with books—The Cellular

Slime Molds, Nonlinear Dynamics and

Chaos, and Principles of Brain Evolution,

to name a few.

While Otchy was majoring in mechan-

ical engineering at the Georgia Institute

of Technology in the late 1990s, he also

worked for a company that specialized

in automating factory systems. His job

was to teach robots to identify things,

whether gadgets or auto parts, and sort

them as they came down a conveyor

belt. “It was just astounding to me how

difficult it was,” he says. “These were

tasks that children do.” His frustrations

lefthimdetermined touncoverthe

innerworkingsofperception,decision-

making,andlearning.Heleftthefac-

torylineand,eventually,madehisway

toneuroscience and the zebra finch.

Songbirds such as the zebra finch

have an unusual skill set. Whereas

most creatures know instinctively how

to make noises, songbirds learn to imi-

tate what they hear, then vary the tunes,

demonstrating some semantic under-

standing of their songs. Decades of

research have pinpointed the structure

in the finch’s brain, what’s known as the

song nucleus, responsible for this behav-

ior. Studying this area has led to rich

insights into how neural circuits func-

tion, in turn informing other research

around how humans move, feel, and

emote. Figuring out how the birds imi-

tate one another could help explain how

we do the same thing, which could prove

important in, say, teaching language

skills to a machine.

Otchy works with about 300 birds

at a BU aviary. For one experiment,

elpingresearcherspuzzle
out the secrets of neural netwo rks

THIS SPREAD: PHOTOGRAPH BY CASSANDRA KLOS FOR BLOOMBERG BUSINESSWEEK