Erich Harth

ArtandReductionism

Allthinkingisdonebyourbrains.Theyarealsoresponsibleforourfeelingsofloveandhate,andforourabilitytomakeandappreciateart.Butthereisapopu-larreluctancetocreditthebrainwithsomeoftheseso-calledhigherfunctions.Wehavedifficultyassociatingourappreciationofbeautywithelectricalimpulsespropagatingdownnervefibres.Wedon’tseeloveasresidingintheorganthatishiddenawayinsidetheskull,whereitsits,shapedlikeaboxingglove,grey,motionless,andseeminglyinert.Instead,theiconofloveisthatfist-sizedmuscleinyourchest.

Wehavelearnedthatthethreepoundsofgreymassintheheadisthemostdel-icateandliveliestobjectweknowofintheuniverse,andthatbelowitsquiet,non-assuming,exterior,billionsofnervecellsareconstantlytendingtoourmanyneeds.

Fouryearsago,TheJournalofConsciousnessStudiesdevotedtwoissuestothequestion,howartrelatestowhatgoesoninthebrain.Inhiseditorialintro-duction,JosephGoguen(1999)statesthatthelargerquestionconfrontedinthisvolumeis,‘whatdoesitmeantobehuman?’

Theleadarticle,TheScienceofArt,byRamachandran&Hirstein(1999)listedeightuniversals,or‘lawsofartisticexperience’,andassignedneuralmechanismstosomeofthese.Inafollow-upinterview,Ramachandran(2001)respondstofrequentcriticismsofhispaper,by(correctly)callingreductionismthe‘mostpowerfulstrategyknowntoscience’.Hedefinesreductionism(wrongly)as‘explainingaphenomenonintermsofthebehaviourofitsconstitu-entcomponents’,whichinthiscasemeansthespecializedsignallingcellsinthebrain,theneurons.ThesamemisunderstandingcausesDonnyaWheelwell(2000),theharshestcriticofthepaperbyRamachandranandHirstein(1999),tocitethewordreductivealongwithsuchpejorativeadjectivesassuperficial,taw-dry,debasing,offensive,andanti-human.

Iwishtoaddressthisverycommonmisunderstandinginthisbriefnote.

Correspondence:

ErichHarth,Departmentofphysics,SyracuseUniversity,Syracuse,NY13244-1130,USA.Email:harth@physics.syr.edu

JournalofConsciousnessStudies,11,No.3–4,2004,pp.111–16

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ReductionisminPhysics

Physicsisoftenconsideredtobeadifficultsubject,mainlybecauseofitsexten-siveuseofmathematics.Atthesametimeitisconceptuallyoneofthesimpleststructures,asitattemptstoweaveaseamlessfabricofcauseandeffectthattakesusfromthesmallestandmostelementarytothemostcomplex.Drasticallydif-ferentsetsofphenomenaareshowntorestonthesameunderlyingprinciplesandlaws.TheclassiccaseofthisunificationbroughttogetherNewtonianmechanicsandthetheoryofheatthroughtheworkofClerkMaxwellandLudwigBoltzmann.Here,themacroscopicscienceofthermodynamicsisreducedtoastatisticaltreatmentofatomiccollisions.

Thistypeofreductionism,whichtakesusfromthelarge(andcomplex)tothesmall(andelementary),isalmosttheruleinphysics.Ithastodowiththefactthat—withinanimatematter—causalityworksmorestronglyfromthesmalltothelargethanintheoppositedirection.Reductionismseeksouttherootsofthiscau-sality.Itisthenatureoftheatomthatdetermineshowbulkmatterbehaves,butthereislittleeffectgoingtheotherway.Weunderstandwhatmakesanicecrys-talbytracingitsstructuretotheknownpropertiesofwatermoleculesandtheforcesbetweenthem,andweunderstandthewatermoleculeasresultingfromthebindingbetweenatomsofoxygenandhydrogen.Itwouldseemfoolishtoproceedintheoppositedirection.Theatomofoxygeninawatermoleculeisnodifferentfromoneinthemolecularoxygenwebreathe,andthemoleculeofwaterdoesn’tknowwhetheritispartofanicicle,awaterfall,orchickennoodlesoup.Ifwewantedto,wecouldcontinuetodescendtotheconstituentelectrons,protons,andneutrons,andtotheultimateelementaryunits,thequarksandgluons.Becauseofthesearchforthesmallest,elementarycauses,Iwillcallthisprocessatomisticreductionism.

Butreductionismdoesnotalwaysseekunderstandingofthelargebylookingforcausesinthesmall.Large-scalestructuresdoaffectphenomenaonasmallerscale:themassofachunkofU235determinesthelocalcascadeoffissionevents.

Nagel’sDefinitionofReductionism

TheLatinrootreduceremeanstoleadback(notnecessarilytowardsmallerscales).Thereductioadabsurdumdemonstratesafaultyargumentbyleadingbacktotheoriginalassumptionandshowingittobeuntenable.Inphysics,aswehaveseen,reductionmostoftenseeksexplanationinelementaryevents.Butthereareexceptions.What,then,dowemeanbyareductionistexplanation?ThephilosopherofscienceErnestNagel,whodefinedreductionism(1961),seesitastheunificationoftwodistinctfieldsofinquiry.Onehecallstheprimarysciencewhichhasthevirtueofgreaterrangeofapplicability,andagenerallymoreelegant,intellectuallysatisfying,structure.AccordingtoNagel,reductionismconsistsofexpressingthelawsandrulesofthesecondaryscienceintermsofthoseoftheprimaryscience.Inthisway,thesecondaryscienceofthermodynamicswasshowntobeexpressibleintermsoftheconceptsandlaws

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oftheprimaryscienceofNewtonianmechanics.Oftentheelementsofthepri-marysciencearesmaller,moreelementary;butnotalways.Nageliscarefulnottostatethisasageneralrule.Thefieldofopticswasreducedtothemoreall-encompassingelectrodynamics.Botharemacroscopictheories.

Nagelsetdownsomeformal,andverystringent,conditionsfortheprocessofreduction.

Itisanobviousrequirementthattheaxioms,specialhypotheses,andexperimentallawsofthesciencesinvolvedinareductionmustbeavailableasexplicitlyformu-latedstatements,whosevariousconstituenttermshavemeaningunambiguouslyfixedbycodifiedrulesofusageorbyestablishedproceduresappropriatetoeachdiscipline.Totheextentthatthiselementaryrequirementisnotsatisfied,itishardlypossibletodecidewithassurancewhetheronescience(orbranchofscience)hasinfactbeenreducedtoanother.

Later,Nageladmitsthatthis‘idealdemand’isnotalwaysrealizableinpractice.Certainly,Ramachandran’seight‘lawsofartisticexperience’fallfarshortofthatideal.

CausalityinLivingMatter

Thereisaquantitativedifferencebetweenlivingandinanimatematterintherel-ativestrengthsoftheupanddownstreamsofcausality.Justasininanimatemat-ter,soinanorganism,thepropertiesofmoleculesstilldeterminewhathappensonalargerscale.ThedetailsofourbodilystructureanditselaboratechemistryaredeterminedbythemicrostructureofDNA.Thecontrolisdelicateandextendsoverseveralordersofmagnitudeinscale.Buthere,unlikeininanimatesystems,thestreamofcausaleventsfromthelargetothesmallispowerfulandever-present.BertrandRussellremarkedthat‘Nopartofanylivingentityandnosingleprocessofanycomplexorganicunitycanbefullyunderstoodinisolationfromthestructureandactivitiesoftheorganismasawhole’.

Thiskindofunityisonlyoccasionallyseenininanimatematter.Wemen-tionedthecaseofchainreactionsinfission.Also,theintegrityandsizeofastararerequiredtosustainthenuclearfiresatitscore.Whentheycease,wespeakofthedeathofthestar.Anextremecaseoftop-downcontrolwasproposedaboutahundredyearsagobytheGermanphysicistErnstMach.Heattributedtheinertiaofeveryobjecttoitsbeingembeddedinauniverseofobjects.

Inlivingthings,thesourceofsuchtop-downcontrolisnotconfinedtoliewithintheboundariesoftheindividual,butincludesalloftheecologicalenvi-ronmentandextendsbackwardsintime.Overmillionsofyears,countlessmem-bersofthespeciescarriedtheDNAthroughtheirbrieflivesand,withtheirstrugglesforsurvival,helpedshapethemoleculetomaketheindividualbetterabletoevadepredators,outwitprey,andachievedominanceamongitsownkind.

TounderstandthecontentsofaparticularDNAmoleculeandtheirsignifi-cance,itisthereforenotsufficienttotracethephysicsandchemistryofitscom-ponentgroupsandthevalencebondsandhydrogenbondsthatlinkthemtogether,andhowitissynthesizedfromitsparentstructurebycodon–anticodon

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bonding.Wemustsearchthepasthistoryofthespeciesandanalysehowtheenvironmentselectedthegenesthatgavetoday’sindividualsthebestchancetoliveandreproduce.

ReductionismandtheBrain

Thehumanbrainisshapednotjustbythebottom-upinfluencesofourgenes,butalsobyawealthoftop-downeffectsofpastexperiences,includingwhatwegen-erallyrefertoasculture.Accordingly,whatweperceivethroughoursensesisdeterminednotjustbythe‘upstream’transportofinformation—Ramachandraanreferstoitasasensory‘bucketbrigade’,butbyawealthofeventsstoredandanticipatedbythebrain.Whatismore,almostanymacro-scopicphysicaleventthatinvolvestheinterventionbyahumanbraincannotbefullyunderstoodbyjustfollowingthechainofcauseandeffectbeginningwithelementaryneuralevents(Burns&Engdahl,1998).Thereisnomysteryinvolvedinthis.

Toillustrate,considerthisscenariosetinasupermarketintheStateofNewYork.Amongthedifferentitemsselectedbytheshoppers,therewillbeanocca-sionalsix-packofbeer.ButnotonSundays.Toexplainthatphenomenon,whichisevidentlycontrolledbythebrainoftheshopper,onecouldresorttooneofthepowerfulnewmeansofmonitoringbrainactivity.AnfMRImayshowthatcer-tainactivitiesinthemotorcortexthathavetodowiththeretrievalofsix-packsofbeerareabsentonSundays.Theinvestigatormightthenbeencouragedtolookforaselectivemotorinhibitorwithasevendaycycle.Ifweareluckyandfindone,thiswillonlyraisemorequestions.Theapproachappearshopeless.Butthereisasimpleandverysatisfactoryexplanation:TheStateofNewYorkhasalawthatforbidsthesaleofalcoholicbeveragesonSundays.Theshoppersknowit.

ThepointIammakinghereistwofold:1)Toarriveatanunderstandingofaphenomenon,especiallyoneinvolvingthehumanbrain,itisoftennecessarytogobeyondatomisticreductionismandconsidertop-downcausation:2)Asatis-factoryexplanationmayinvolvenon-physicalfactors,suchastheknowledgeoflaws,intheaboveexample,andtheanticipationofbeingstoppedatthecheckoutcounterwheninviolation.Simplystated,eventsinthemind(knowledge,desires,etc.)‘canhavethestatusofscientificentities’,asBrownhasstated(1999),thatis,theycanbepartofanintellectuallysatisfyingcausalframework.Thisisnottodenytheexistenceofaseamlesschainofphysicalcauses,butthedetailsofthesemaybebothinaccessibleanduninteresting.

BeyondtheReflex

Apossibledivisionbetweenwhatisunderstandableinbrainfunctionsintermsofelementaryneuralmechanisms(atomisticreductionism),andwhatisnot,maybefoundinthedifferenttimescalesonwhichtheseprocessestakeplace.Fastperception,includingdiscriminationandselectivemotorfunction,sometimescalledcorticalreflexes,canbecompletedinjustafewtenthsofasecond.Thus,

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ThorpeandFabreThorpe(2001)haveshownhowavisualdiscriminationtaskinvolvespropagationofinformationfromtheretinaviaLGNtotheprimaryvisualcortex,thenalongoneofthebranchesofthevisualpathway,totheprefrontalcortex,thenfromtheretothepre-motorandmotorcortex,thendownthespinalcordtothemotoneuronsthatenervatetheappropriatemuscles.Intheanimalstested,thiswholeprocess,fromeyetoaction,takesplaceinsomethingliketwotenthsofasecond,fromwhichtheauthorsconcludedthatnofeedbackloopsareinvolved.Itisstrictlyfeed-forward,orwhatRamachandrancharacter-izedasthebucketbrigade.

Bycontrast,thedurationofrelevantneuralmechanismsinmostthoughtpro-cesses,includingthecreationandcontemplationofworksofart,ismanytimesthetimerequiredforneuralsignalstotraversetheentirebrain.Weconcludethatthisinvolvessustained,reverberatoryactivitywhichtouchesonapanoplyofstoredinformationandreleasesawealthofassociations,memoriesandemo-tions.Iwanttosuggestthatsuchbrainfunctions—likethoseofthesupermarketshopper—generallydonotallowadetailedanalysisintermsofaseamlesschainofmicroscopicneuralevents.

ReductionismandArt

Weappreciateandenjoyartisticexpression.Someofusalsotrytounderstanditsrootsandphenomenology.TheapproachbyRamachandranandHirstein(1999)andRamachandran(2001),inwhichthecausesofartisticrulesaresoughtinthemicroworldofneuralmechanisms,while‘ignoringthecomplexitiesimposedbyculture’,offerslittlehopeforanysignificantinsightandinvitesthecommoncrit-icismofwhatissometimescalleda‘reductionistapproach’.Thatiswhymostofusderivegreaterintellectualsatisfactionfromagoodarthistory(suchasE.H.Gombrich,1960),thanfromatheoryofartthatattemptstoapplyatomisticreductionismwhileneglectingthe‘complexitiesimposedbyculture’.

Isknowledgeofourbrainirrelevantinrelationtoart?Ofcoursenot,thoughZeki(1999)overstatesthecasesayingthat‘notheoryofaestheticsislikelytobecomplete,letaloneprofound,unlessitisbasedonanunderstandingofthework-ingsofthebrain’.Manymentalstateshaveknowncorrelatesinneuralactivities.Thescienceofseeinghasmuchtotellusabouthowwemakeandviewimages.Visioninthehumanbrainisasystemofloopsandrecurrentpathways(Yingling&Skinner,1977;Felleman&VanEssen,1991)thatlinkperipheralimagesandcentralsymbols,thespecificandthegeneral,sensationandknowledge.Ihavestressedthesignificanceofthesestructuresinouruseofinternalsketchpadsinreasoningandimagery(Harth,etal.,1987;Harth,1993;1995),andthenaturalextensionofthisprocesstothecreationofexternalimages(Harth,1999).

Ultimately,aprofoundevaluationofartisticexpressionmustinvolveboththeworldatlarge,whichisitsinspiration,andthehumanbrain,whichiscapableofbeinginspired.

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