NeuroscienceLettersxxx (2013) xxx–xxx
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Neuroscience
Letters
j o ur na l h o me p a g e :w w w . e l s e v i e r . c o m / l o c a t e / n e u l e t
Word-induced
postural
changes
reflect
a
tight
interaction
between
motor
and
lexico-semantic
representations
Douglas
M.
Shiller
a,b,c,∗,
Nicolas
Bourguignon
a,b,c,
Victor
Frak
d,
Tatjana
Nazir
e,
Q1Geneviève
Cadoret
d,
Maxime
Robert
b,d,
Martin
Lemay
b,daÉcoled’orthophonieetd’audiologie,UniversitédeMontréal,Montreal,Canada bCHUSainte-JustineResearchCentre,Montreal,Canada
cCentreforResearchonBrain,LanguageandMusic,McGillUniversity,Montreal,Canada dDépartementdeKinanthropologie,UniversitéduQuébecàMontréal,Montreal,Canada eL2C2-InstitutdesSciencesCognitives,CNRS/UCBL,UniversitéClaudeBernardLyon1,Lyon,France
h
i
g
h
l
i
g
h
t
s
•Kinematicanalysesrevealacouplingbetweenlexico-semanticaccessandposturalcontrol.
•Listeningtoactionverbs,butnotmental-stateverbs,disruptsthecontrolofquietstanding.
•Theresultssupportoverlapinneuralprocessingofactionwordsandwhole-bodymotorfunctions.
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t
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Articlehistory: Received30July2013
Receivedinrevisedform23August2013 Accepted8September2013 Keywords: Posturalcontrol Languageprocessing Lexicalaccess Embodiedcognition
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Atightcouplingbetweenlexico-semanticaccessandmotorcontrolhasbeenestablishedonthebasis
ofneuropsychological,neurophysiological,andbehavioralevidence.Forexample,sensoryandmotor
corticeshavebeenshowntobeactivewhensubjectslistentowordsdenotingbodilyactions.Kinematic
analysesofparticipants’motoractionsduringtheprocessingoflinguisticstimuliprovidefurtherinsights
intothenatureandtime-courseofthisrelationship.However,suchstudieshavelargelyfocusedon
individualbodyparts,inparticulartheupperlimbs,thusneglectingtheeffectoflanguageprocessingon
lowerorwholebodyrepresentations.Thepresentstudybridgesthisgapbyevaluatingtheinteraction
betweenlinguisticprocessingandwhole-bodyposturalcontrolduringquietstanding.Theresultsreveal
asystematicinfluenceofpassivelisteningtoactionverbs,butnotmental-stateverbs,onmeasuresof
posturalcontrol,pointingtoaclearandspecificneurallinkbetweenwordsconveyingactionconcepts
andwhole-bodymotorfunctions.
© 2013 Published by Elsevier Ireland Ltd.
1. Introduction
Psycholinguistic models positing that words acquire their meaning fromsomatosensory representations in thebrain (i.e., “embodiedcognition”,[1])havebeensubjecttoenthusiasm[1,2] andcriticism[3,4].Supportforalinkbetweenlanguageandaction is basedonneuropsychological, neurophysiological, and behav-ioral data. Reports of an inabilityto execute volitional actions followingverbalcommandsdespitepreservedreceptivespeech[5] suggestthatlanguagemediatesmotorcontrol.Aninabilitytoaccess themeaningofactionverbs(e.g.,“cutting”or“sailing”)following
∗ Correspondingauthorat:UniversitédeMontréal,Facultédemédecine,École d’orthophonieetd’audiologie,C.P.6128,SuccursaleCentre-Ville,Montréal,Québec H3C3J7,Canada.Tel.:+15148155421;fax:+15143432115.
E-mailaddress:douglas.shiller@umontreal.ca(D.M.Shiller).
lesionsinthepremotorcortexindicatesthatthisphenomenonis bidirectional[6].Thiscorrelationhasbeencorroboratedin neu-roimagingstudies,demonstratingthatsomatosensorycorticesare activewhensubjectslistentowordsthatdenotebodilyactions, Q2 suchas“kick”(legrelated)or“lick”(tonguerelated,[7,8];Boulenger etal.,2009)eitherinsinglewords[7]orinsentences[9].
Kinematic analysesof participants’ motor control have fur-ther elucidatedthenature and time-course ofthese correlates. Forinstance,Fraketal.[10]askedparticipantstoholdacylinder equippedwithgripforcesensorswhilelisteningtoactionverbs (e.g.,“write”)ornon-actionconcretenouns(e.g.,“cliff”).Increased gripforcewasrecordedapproximately260msafterhearing action-relatedverbsbutnotafterhearingnon-actionnouns.Similareffects ofword typeonarmmovement havebeenobservedin several otherkinematicstudies[11–13].Theseresultsindicatethatthelink betweenlanguageandmotorcontrolissensitivetosubtle manip-ulationsoflinguisticcontext.
0304-3940/$–seefrontmatter © 2013 Published by Elsevier Ireland Ltd. http://dx.doi.org/10.1016/j.neulet.2013.09.021 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55
tionbetweenlanguageandaction,littleisknownaboutthislink beyondgoal-directedmovementsinvolvingtheupperlimbs.The presentstudyexploresthenatureofthisrelationinthecontext ofwhole-bodyposturalcontrolduringquietstanding.Theneural mechanismsofposturalcontrolinvolveacontinuousprocessingof sensorydatafromthevisual,proprioceptiveandvestibularsystems torapidlydetectself-movement(sway)andgeneratean appropri-atemotorchangestomaintainbalance[14].Thissensorimotorloop providesasensitivecontextinwhichtoexaminetransient modu-lationsinneuralsensoryandmotorprocessing.Interferingwith anycomponentofthissystem,evenbriefly,mayresultinsubtle instabilitythatcanbereadilymeasured(Sensory:[15,16];Motor: [14,17]).
Our goal is to examine the specificity of the link between language and motor functions by contrasting the influence of verbswhosemeaningrelatestophysicalmovement(e.g.,tomber –“fall”;courir–“run”)withverbsreferringtomentalstates(e.g., aimer“love”;decider“decide”).Previous studiesexamining lan-guage–motorinteractionshavecontrasteddifferentwordclasses, suchasactionverbsandconcretenouns.However,itisof inter-esttounderstandtheextenttowhichdistinctclassesbelonging toanotherwise similargrammaticalcategory mayexert differ-enteffectsonmotorcontrol.Priorneurophysiologicalstudieshave founddifferencesinneuralactivitybetweenactionand mental-stateverbs[18,19],whichmaydifferentlyinfluencemotorcontrol. Here,weobserveda systematicinfluenceofpassivelisteningto action-orientedverbs,butnotmental-stateverbs,onmeasuresof standingposturalcontrol,whichrevealsaclearandfunctionally specificneurallinkbetweentheprocessingofwordsconveying actionconceptsandwhole-bodymotorfunctions.
2. Materialsandmethods
2.1. Participants
FourteennativeFrenchspeakersweretested(9womenand5 men,22–32yearsofage),withnohistoryoflanguageorhearing disorder(hearingstatuswasverifiedimmediatelypriortotesting usingapure-toneaudiometricscreener).Participantsreportedno historyofmotororvestibulardisorder,andallobtainedthe max-imumpossiblescore(56)ontheBergBalanceScale.Participants wereallright-legdominant,asverifiedbytheBruininks-Oseretsky testofmotorproficiency.
2.2. Stimuli
TwolistsofFrenchwordswerecreatedforuseinthisstudy: oneconsistingof24verbswhichclearlyconveyactionspertaining tothelowerlimbs,andasecondlistof24verbsassociatedwith changesinmentalstateandconnotenophysicalaction(Table1). The24actionwordswereselectedfromalargersetof45 candi-dateactionverbsonthebasisofalisteningstudyinwhich15native Frenchspeakers(differentfromthoseinvolvedinthepresentstudy ofposturalcontrol)ratedeachwordonascaleof1–5,where1=no associationwithlowerlimbmovement,and5=strongassociation withlowerlimbmovement.The24wordswiththehighest aver-agescoresonthisratingscalewereusedinthepresentstudy.A listof24verbsconnotingnophysicalaction,butratherchanges inmentalstate,wascreatedsuchthatitmatched,onaverage,the listofactionwordsinterms ofusagefrequency,numberof let-ters,numberofsyllables,aswellasthefrequencyofoccurrence of2-and3-consonantclusters(see[10]forasimilarprocedure). Thewordlistsweredigitally recordedat44.1kHz (16-bit)by a singlefemaleFrenchspeakerandamplitudenormalized.Average
ListofFrenchverbspresentedtosubjectsdenotingbodilyaction(leftcolumn)and mentalstate(rightcolumn),alongwiththeirEnglishtranslations.
Action Non-action
French Englishtrans. French Englishtrans. Agenouiller tokneel Accepter toacknowledge
Asseoir tosit Adorer toadore
Avancer tomoveforward Ambitionner tocovet Balader tostroll Aspirer toaspire
Boiter tolimp Choisir tochoose
Bondir toleap Concevoir toimagine Cavaler togallop Consentir toconsent Cheminer towalk Daigner tocondescend Chevaucher toride Décider todecide Clopiner tohobble Désirer todesire Courir torun Détester todetest/hate Danser todance Envisager toenvision Enjamber tostepover Essayer totry Escalader toclimb Hésiter tohesitate Gambader toskip Préférer toprefer Glisser toslip Prétendre toclaim
Marcher towalk Prévoir toforesee
Pédaler topedal Projeter toplan
Piétiner tostamp Renoncer togiveup Promener towalkaround Répugner tobereluctant
Sauter tojump Rêver todream
Trébucher tostumble Songer tothinkdeeply
Trotter totrot Souhaiter towish
Valser towaltz Tenter toattempt
durationofthewordswas0.64s(SD:0.11),withnoreliable dif-ferencebetweenthe24actionwordsandthe24non-actionwords (t[46]=1.63,p>0.05).Thewordswerepresentedtoparticipants overloudspeakers(MSP7,Yamaha,Japan)inanaudiometrictesting boothatavolumeofapproximately60dBSPL.
2.3. Procedure
Eachparticipantunderwenttwoblocksofword-presentation trialsinvolvingtherandomizedpresentationofall48words(24 actionand24non-actionwords),withaninter-stimulusinterval of10s.Participantswereaskedtomaintainaquietuprightposture whilestandingonaforceplate(seedataanalysis)withtheireyes closedthroughoutthepresentationofeachblock.Theirfeetwere placedathipwidthinanaturalpositionandtheirarmswereat theirsides.Datacollectionbeganwhentheparticipantwasstable ontheplatform.A2-minutebreakwasprovidedbetweenthetwo blocksoftrials.
Tomaintainattentiontotheauditorystimuli,participantswere instructedtosilentlycountthenumberoftimesatargetwordwas presentedthroughout eachblockoftrials.A differentrandomly selectedtargetwordwaspresentedtosubjectsimmediatelyprior totheonsetofeachblock.Thetargetwordwasthenpresented 10times,atrandomintervals,throughoutthestimulusblock.Each participantcarriedoutthelisteningtaskoncewiththetargetword selectedfromthelistof24actionwords,andoncewiththetarget wordselectedfromthelistof24non-actionwords(order counter-balancedamongparticipants).
2.4. Dataanalysis
Force in two dimensions (M-L, medio-lateral; A-P antero-posterior)wassampledat100Hzusingaforceplatform(model ACG,AMTI,Watertown,MA)anddigitallylow-passfilteredat6Hz usingasecond-orderButterworthfilter(Matlabv.7.0,Mathworks, Natick,MA)priortothecalculationoftheCenterofPressure(CoP) alongeachaxis(M-LandA-P).CoPreflects,ateachmoment,the spatialpositionatwhichthesumofforcesexertedbythebody actsontheforceplate,andvariationinCoPisacommonlyused 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150
D.M.Shilleretal./NeuroscienceLettersxxx (2013) xxx–xxx 3 2 3 4 5 6 7 8 9 6.2 6.4 6.6 6.8 7 7.2 7.4 Time (Sec)
Range
2 3 4 5 6 7 8 9 20 20.5 21 21.5 22 22.5 23 23.5 24 Time (Sec) 2 3 4 5 6 7 8 9 2.4 2.5 2.6 2.7 2.8 2.9 3 3.1 3.2 3.3 Time (Sec)RMS
Non Action Words Action Words p < 0.05 p < 0.05 (Corrected) A P M L 0 0.2 0.4 0.6 0.8
Range
Axis
A P M L 0 0.5 1 1.5 2 2.5Maximum Velocity
Axis
A P M L 0 0.05 0.1 0.15 0.2 0.25RMS
Axis
A)
B)
Maximum Velocity
Fig.1. (A)Themeandifferencebetweenactionandnon-actionwordconditionsformeasuresofCoPRange(mm),maximumvelocity(mm/s)andRMS(mm).Positive differencescoresreflectalargermeanvaluefortheactionwordsrelativetothenon-actionwords.Starsindicatedifferencescoresthatdiffersignificantlyfromzero(p<0.05) (M-L:Medio-lateral;A-P:Antero-posterior).(B)AveragetimeseriesofCoPrange(mm),maximumvelocity(mm/s)andRMS(mm)measures,averagedovertrialscontaining actionwords(solidlines)ornon-actionwords(dashedlines).Timesarerelativetowordpresentationonset.Stars(*)anddiamonds(♦)indicatetimepointsduringwhich theconditionsdifferreliably(*=uncorrectedp<0.05;♦=Holm–Bonferronicorrectedp<0.05;seetextfordetails).
indexofposturalinstabilityinstanding[14].Threepreviously val-idatedkinematicmeasuresofposturalvariationinvolvingCoP(see e.g.,[20–22])werecomputedinM-LandA-Pdirectionsforthe9-s periodfollowingthepresentationofeachword:(1)range, reflect-ingthetotalexcursionofCoP,(2)peakvelocity,reflectingthelargest suddenchangeinCoP,and(3)root-meansquare(RMS),reflecting theaveragemagnitudeofvariation.Theanalysisdidnotinclude thetimeduringwhichthestimuluswasbeingpresentedinorder toreducetheinfluenceoflow-leveleffectsofauditoryinput,such astheacousticstartleresponse.Foreachparticipant,thethree pos-turalmeasureswereseparatelyaveragedacrossallpresentationsof theaction-wordsandallpresentationsofnon-actionwords.Trials involvingthetargetstimulusforthewordmatching/countingtask wereexcludedfromtheaverage.Foreachofthekinematic meas-ures,thedifferencebetweenthetwowordconditions(actionvs. non-action)wasevaluatedusingapaired-samplest-test.
3. Results
Themeandifferencebetweenactionandnon-actionword con-ditionsisshownforeachoftheposturalcontrolvariablesinFig.1a. Positivedifferencescoresreflectalargermeanvaluefortheaction wordsrelativetothenon-actionwords.Statisticallyreliable differ-enceswereobservedintheA-PdirectionforCoPRange(t[13]=3.27, p<0.05;Cohen’sd:0.17),maximumvelocity(t[13]=2.23,p<0.05;
Cohen’sd:0.19)andRMS(t[13]=2.73,p<0.05;Cohen’sd:0.17).No reliabledifferencewasobservedforanyofthemeasuresintheM-L direction(p>0.05).
Toexaminetheevolutionofthereliableeffectsinpostural con-trolthroughoutthe9-speriodfollowingwordpresentation,theCoP measuresintheA-Pdirectionwerere-calculatedasatime-series using2-stimewindowscenteredateachsecondofeachtrial.For eachparticipant,anaveragetime-serieswascomputedacrossall action-wordandnon-actionwordtrials,permittingacomparison betweenconditionsatsuccessivemomentsintimeusingpair-wise repeated-measurest-tests.Astraditionalcorrectionsformultiple comparisonswillbeoverly-conservativefortime-seriesdatasuch asthesebecausetheycannotaccountfortheautocorrelatednature ofthedata,wepresentresultscorrectedformultiplecomparisons usingtheHolm–Bonferronimethod[23],aswellasuncorrected results.
Fig.1bshowstheevolutionofthethreeCoPmeasurefor tri-als involving action words (solid lines) and non-action words (dashed lines). On average, CoP range showed a transient dif-ference betweenthetwoword conditionsthat wasstatistically reliable(correctedp<0.05)4–5sfollowingwordonset(or4–6s usinguncorrectedpvalues),atwhichpointthetwocurves con-vergeonceagain.TheCoPmaximum velocitymeasurewasnot foundtodeviatereliablybetweenthetwoconditions(corrected p>0.05)atanysingletimewindow,howeverareliabledifference 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198
ues(p<0.05).TheRMSmeasureshowsarobustdifferencebetween wordconditions(correctedp<0.05)thatbeginsearlier(2s)andis observedupto6sfollowingwordonset(or2–7susinguncorrected pvalues).Takentogether,thesetime-seriesindicatethatthe influ-enceofwordmeaningonposturalcontrolmanifestsreliablywithin 2sfollowingwordpresentation,onaverage,andthattheeffectis transient,becomingnon-significantwithin6–7s.
4. Discussion
Thepresentstudyaimedtogainfurtherinsightsintothe rela-tionshipbetween lexicalaccess and motor control.Contrary to mentalstateverbs,verbsdenotingphysicalmovementwerefound toinducesmallbutsystematictransientchangesinwhole-body posture.Thiscomplements existingevidencesupportinga tight couplingbetweenthelexico-semanticprocessingofwords– par-ticularlythosedenotingphysicalaction–andtheneuralcontrolof motorfunction.
Verbsdenotingbodymovementappeartobeassociatedwith increasedneuralactivityoftheirrespectivesomatotopicloci([7,8]; Boulengeretal.,2009)andinterferewithtaskexecution[10–13]. Ourown resultsextendthesefindingsby pointing toalinkage betweenlexicalandbodilyrepresentationsthatalsoencompasses whole-bodyexperience.
Our resultsdifferfrom previousbehavioral studies in terms ofthetimecourseoftheinfluenceofwordprocessingonmotor control.Changesingripforce,forexample,havebeenobserved approximately100msfollowingtheonsetofthetargetword,with theeffectdiminishingafter400ms(e.g.,[10]).Whilenotstudiesof wordprocessing,theintegrationofauditory-sensoryinputinthe planningoflimbmotoractionshasalsobeenshowntooccurat latenciesoflessthan1s(seee.g.,[24]).Incontrast,thevariablesin thepresentstudywereshowntoexhibitchangesthatbeganwithin thefirst2-speriodfollowingwordonsetandlastedupto6–7s.This differenceislikelyrelatedtothenatureofthemotorbehaviorbeing measured.Unlikegripforceandupperlimbmovement,changes instandingpostureresultfromtheaggregateactivityof numer-ousmusclegroupsdistributedthroughoutthebody.Asaresult, whilechangesinorientationmaybesensedrapidly,changes in whole-bodyposture–reflectingtheactivityofspatiallydistributed muscles–aretypicallyobservedafterseveralseconds[15,16]. Pos-turalsway, whichincludesoscillatorycomponentsin therange of0.5–2.5Hz[25,26],lendsitselftoananalysisof variabilityas anindexofposturalcontrol.Becauseofthelonglatencyofthese whole-bodyoscillations,kinematicmeasuresofposturalcontrol requireatimewindowontheorderofsecondstoavoidinstability. Itispossiblethattheonsetofchangesinposturalmuscleactivity occurredearlierthan1sfollowingstimuluspresentation. Incorpo-ratingphysiologicalmeasuresofmotorbehavior,suchasEMG,may provideamoredetailedunderstandingofthetime-courseofthese effects.
Toourknowledge,onlyonestudytodatehastestedtheeffect oflanguageprocessingonposturalcontrol[27].Inthisstudy, par-ticipants’CoPmeasuresweremonitoredastheyproducednouns evokingmotor control(e.g.,tools)or nounsdevoidofanysuch meaning (e.g., cities). Producing words from the former cate-goryyieldedgreaterCoPchanges,demonstrating aninteraction betweenposturalcontrolandwordproduction.Whilethisresult isconsistentwiththose of thepresent study,itsinterpretation iscomplicated bythefact thatthesemantic manipulationmay haveinteracteddirectlywithkinematicparametersofthespeech behavior(includingheadmotion),and thusindirectlywith pos-turalcontrolviathoseparameters[28].Suchdifficultiesarereadily avoidedinthepresentstudy.
ent measures was observed in both A-P and M-L directions followingpresentationoftheaction-words(seeFig.1a),statistically reliablechangesinposturalkinematicswereonlyobservedinthe A-Pdirection.Thereasonforthisislikelybiomechanicalinnature. Inquietstanding,withfeetplacedparallelathipwidth,thebodyis considerablymorestableintheM-LdirectionthanintheA-P direc-tion.Asaresult,M-LCoPdisplacementsaretypicallymuchsmaller (e.g.,[29]).Thiswasreflectedinthethreedependentmeasuresof CoPvariabilityinthepresentstudy,withallthreeshowingaverage magnitudesintheA-Pdirection(Range:12.71,Maxvelocity:31.60, RMS:2.92)thatweremorethantwiceaslargeasthoseintheM-L direction(Range:5.89,Maxvelocity:17.00,RMS:1.26).Aspostural adjustmentsduringquietstandingareprimarilyobservedinthe A-Pdirection,itisinthisaxisthatdifferencesbetweenconditionsare alsomostreadilyobserved.
Aconcernthatmayberaisedinstudiesoflexical–motor interac-tionsisthataction-words,byvirtueoftheirbeingassociatedwith physicalbehavior,mayalsobemoreconcreteandimaginable.At issuehereisthepossibilitythatsubjectsmayhaveinfact expe-riencedsomesort of“motorimagery”(i.e.,covertsimulationof themotoraction)immediatelyfollowingthepresentationofaction words,consequentlyinducinga postural changein responseto theimaginedmovement.Inthepresentstudy,participantswere instructedtostandquietlywhile carrying outa secondary task (identifyingandcountingthenumberoftimesatargetwordwas played).Nomentionofmotoractionormotorimagerywasmade, hencetheideathatthismayhaveplayedarolepresumesthat sub-jectsspontaneously(andinvoluntarily)performedsuchimagery whilecarryingoutthesecondarytask.
Thereareseveralfactorsindicatingthatmotorimagerywasnot thesourceoftheobservedchangesinpostural variability. Neu-roimagingstudieshaveshownthattheearliestfunctionalchanges incorticalmotorareasfollowingthepassivepresentationof action-wordsareobservableat latenciesunder 200ms,indicating that suchmotoractivationislinkedwithlexicalprocessingandnotdue topost-lexicalprocessessuchasmotorimagery(seee.g.,[2]).As notedabove,changesinposturalcontrolareslowbytheir physi-calnature.Inthepresentstudy,weobservedsystematicchanges in postural control for action wordswithin 2s following word presentation.Thislatency,whileslowinrelationtonon-postural behaviors,isconsistentwithobservedkinematic(CoP)and physio-logical(EMG)adaptationsofposturalcontrolinresponsetosimple changesinsensoryinput.Forexample,Sozzietal.[16]observed postural adaptations to the presence or absence of visual and hapticinputatalatencyof0.5–2.2s.Hencethetimingofthe pos-turaleffectsobservedinthepresentstudyisnotlongerthanthat expectedforsimplesensory-mediatedadjustments.
Incontrast,changesinposturalcontrolduetomotorimagery mightreasonably bepresumedtorequirelongerlatenciesthan thoseobservedhere.Thereisnodataonthetimingofpostural responsestomotorimageryofwhole-bodyaction,andinfactit remainsunknownwhethermentalimageryofmovementwould induceanymeasurablechangesinposturalkinematicsatall. How-ever, if we consider the possibility that subjects did carry out suchimageryinvoluntarily,itwouldpresumablyrequiretimefor posturaladjustmentsinadditiontolexical-semanticaccess (deter-miningthemeaningoftheword,observedatlatenciesaslongas 400msforwordspresentedwithoutcontextualcues;e.g.,[30]),as wellasthetimetoinitiateamentalsimulationofthemotor behav-ior(believedtobetemporallysimilartorealphysicalaction;see e.g.,[31]).
Theposturalchangesinthepresentstudyfollowingthe presen-tationofactionverbswereobservedtocontinueforapproximately 6–7s(Fig.1b).Itisthuspossiblethatmotorimageryplayedarole atalaterpointduringthisperiod.Theideaofmotoreffectsarising 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327
D.M.Shilleretal./NeuroscienceLettersxxx (2013) xxx–xxx 5 fromdifferentsources(lexical-semanticrepresentationinmotor
areasaswellasmotorimagery)hasbeenraisedpreviouslyin stud-iesshowingprolongedeffectsofaction-wordpresentationonlimb motorfunction[10],and isapossibilityinthepresentstudyas well.Identifyingthesedifferentpossiblesourcesinfuturestudies willlikelyrequireneuroimagingtechniqueswithgoodspatialand temporalresolution,suchasMEG.
Inthepresentstudy,subjectsstoodwiththeireyesclosedduring quietstandinginordertominimizepossibleinterferencefromthe visualsystem.Posturalcontrolwithoutvisionmayhaveincreased relianceonproprioception,andhencemayhaveenhanced interac-tionswithlexicalrepresentationsofwholebodymovement.Future studiescontrastingposturalcontrolwithandwithoutvisualinput mayfurtherelucidatetheroleofdifferentsensorymodalitiesinthe observedlexico-motorinteractions.
Despiteevidencethatlexico-semanticprocessing“infiltrates” sensory and motor structures in the brain, why and how this phenomenontakesplaceremainselusive.Someresearchershave speculatedthatsuchinteractionsreflecttheuseinhumansofbrain areasthatoriginallyevolvedfortheperceptionandproductionof action(e.g.,themirror-neuronsystem)fortheprocessingof lan-guage,thuspreservingalinkbetweentheperceptionandplanning ofgoaldirectedactionsandtheirrelated lexicalrepresentations (seee.g.,[32]).
Amajorchallengeremainstodevisemethodsthatcan demon-strateacausallinkbetweenthesefunctions.Untilthen,itremainsa valuableendeavortodelineateaspreciselyaspossiblethedomains of language that share a common semantic organization with sensorimotorrepresentations.
Uncitedreferences
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[33–36]
Acknowledgements
WethankIsabelleRobertforassistingdatacollection.Thiswork wassupportedbytheNaturalSciencesandEngineeringResearch CouncilofCanadaandtheNationalInstituteonDeafnessandother CommunicationDisorders(R01DC012502).
References
[1]V.Gallese,G.Lakoff,Thebrain’sconcepts:theroleofthesensory-motorsystem inconceptualknowledge,CognitiveNeuropsychology22(3/4)(2005)455–479. [2]F.Pulvermüller,Brainmechanismslinkinglanguageandaction,NatureReviews
Neuroscience6(2005)576–582.
[3]G.Hickok,Theroleofmirrorneuronsinspeechperceptionandactionword semantics,LanguageandCognitiveProcesses25(6)(2010)749–776. [4]B.Z.Mahon,A.Caramazza,Acriticallookattheembodiedcognitionhypothesis
andanewproposalforgroundingconceptualcontent,JournalofPhysiology 102(2008)59–70.
[5]N.Geschwind,Disconnexionsyndromesinanimalsandman,Brain88(2) (1965)237–294.
[6]A.R.Damasio,D.Tranel,Nounandverbsareretrievedwithdifferently dis-tributedneuralsystems,ProceedingsoftheNationalAcademyofSciencesof theUnitedStatesofAmerica90(1993)4957–4960.
[7]O.Hauk,I.S.Johnsrude,F.Pulvermüller,Somatotopicrepresentationofaction wordsinhumanmotorandpremotorcortex,Neuron41(2004)301–307. [8]F.Pulvermüller,Y.Shtyrov,R.Ilmoniemi,Brainsignaturesofmeaningaccess
inactionwordrecognition,JournalofCognitiveNeuroscience17(6)(2005) 884–892.
[9]M.Tettamanti,G.Buccino,M-C.Saccuman,V.Gallese,M.Danna,P.Schifo,F. Fazio,G.Rizzolatti,S.F.Cappa,D.Perani,Listeningtoaction-relatedsentences
activatesfronto-parietalmotorcircuits,JournalofCognitiveNeuroscience17 (2)(2005)273–281.
[10]V.Frak,T.Nazir,M.Goyette,H.Cohen,M.Jeannerod,Gripforceispartofthe semanticrepresentationofmanualactionverbs,PLoSONE5(3)(2010). [11]V.Boulenger,A.C.Roy,Y.Paulignan,V.Deprez,M.Jeannerod,T.Nazir,Cross-talk
betweenLanguageProcessesandOvertMotorBehaviorintheFirst200msec ofProcessing,JournalofCognitiveNeuroscience18(10)(2006)1607–1615. [12]R.Fargier,M.Ménoret,V.Boulenger,T.Nazir,Y.Paulignan,GraspItLoudly!
Supportingactionswithsemanticallycongruentspokenactionwords,PLoS ONE7(12)(2012).
[13]P.Aravena,Y.Delevoye-Turrell,V.Deprez,A.Cheylus,Y.Paulignan,V.Frak, T.Nazir,Gripforcerevealsthecontextsensitivityoflanguage-inducedmotor activityduringactionwordsprocessing:evidencefromsententialnegation, PLoSONE7(12)(2012).
[14]D.A.Winter,Humanbalanceandposturecontrolduringstandingandwalking, GaitandPosture3(4)(1995)193–214.
[15]S.Sozzi,A.Monti,A.M.DeNunzio,M.C.Do,M.Schieppati,Sensori-motor inte-grationduringstance:timeadaptationofcontrolmechanismsonaddingor removingvision,HumanMovementScience30(2)(2011)172–189. [16]S.Sozzi,M.C.Do,A.Monti,M.Schieppati,Sensorimotorintegrationduring
stance:processingtimeofactiveorpassiveadditionorwithdrawalofvisualor hapticinformation,Neuroscience212(2012)59–76.
[17]L.Nashner,M.Woollacott,G.Tuma,Organizationofrapidresponsesto pos-turalandlocomotor-likeperturbationsofstandingman,ExperimentalBrain Research36(1979)463–476.
[18]J.Rodriguez-Ferreiro,S.P.Gennari,R.Davies,F.Cuetos,Neuralcorrelatesof abstractverb processing,JournalofCognitiveNeuroscience23(1)(2011) 106–118.
[19]N.Bourguignon,J.E.Drury,D.Valois,K.Steinhauer,Decomposinganimacy reversalsbetweenagentsandexperiencers:anERPstudy,Brain&Language 122(2012)179–189.
[20]N.Kirshenbaum,C.L.Riach,J.L.Starkes,Non-lineardevelopmentofpostural controlandstrategyuseinyoungchildren:alongitudinalstudy,Experimental BrainResearch140(2001)420–431.
[21]J.A.Raymakers,M.M.Samson,H.J.Verhaar,Theassessmentofbodyswayand thechoiceofthestabilityparameter(s),Gait&Posture21(1)(2005)48–58. [22]B.Isableu,B.Fourre,N.Vuillerme,G.Giraudet,M.-A.Amorim,Differential
inte-grationofvisualandkinaestheticsignaltouprightstance,ExperimentalBrain Research212(2011)33–46.
[23]S.Holm,Asimplesequentiallyrejectivemultipletestprocedure,Scandinavian JournalofStatistics6(2)(1979)65–70.
[24]A.Sedda,S.Monaco,G.Bottini,M.A.Goodale,Integrationofvisualand audi-toryinformationforhandactions:preliminaryevidenceforthecontribution ofnaturalsoundstograsping,ExperimentalBrainResearch209(3)(2011) 365–374.
[25]G.H.Begbie,Someproblemsofposturalsway,in:CIBAFoundationSymposium onMyotatic,KinestheticandVestibularMechanisms,1967,pp.80–104. [26]T.Kiemel,K.S.Oie,J.J.Jeka,Slowdynamicsofposturalswayareinthefeedback
loop,JournalofNeurophysiology95(3)(2005)1410–1418.
[27]A.D.Rodriguez,M.L.McCabe,J.R.Nocera,J.Reilly,Concurrentwordgeneration andmotorperformance:furtherevidenceforlanguage–motorinteraction,PLoS ONE7(5)(2012).
[28]M.C.Dault,L.Yardley,J.S.Frank,Doesarticulationcontributetomodifications ofposturalcontrolduringdual-taskparadigms?CognitiveBrainResearch16 (3)(2013)434–440.
[29]S.Nejc,R.Jernej,S.Loefler,H.Kern,Sensitivityofbodyswayparametersduring quietstandingtomanipulationofsupportsurfacesize,JournalofSportsScience andMedicine9(2010)431–438.
[30]P.J.Holcomb,H.Neville, Auditoryand visualsemanticpriminginlexical decision:acomparisonusingevent-relatedbrainpotentials,Languageand CognitiveProcesses4(1990)281–312.
[31]M.Jeannerod,Therepresentingbrain:neuralcorrelatesofmotorintentionand imagery,BehavioralandBrainSciences17(1994)187–245.
[32]G.Rizzolatti,M.A.Arbib,Languagewithinourgrasp,TrendsinNeurosciences 21(1998)188–194.
[33]A.Barrós-Loscertales,J.González,F.Pulvermüller,N.Ventura-Campos,J.C. Bus-tamante,V.Costumero,M.A.Parcet,C.Ávila,Readingsaltactivatesgustatory brainregions:fMRIevidenceforsemanticgroundinginanovelsensory modal-ity,CerebralCortex22(11)(2012)2554–2563.
[34]V.Boulenger,Subliminaldisplayofactionwordsinterfereswithmotor plan-ning:acombinedEEGandkinematicstudy,JournalofPhysiology102(2008) 130–136.
[35]J.Gonzalez,A.Barros-Loscertales,F.Pulvermüller,V.Meseguer,A.Sanjuan,V. Belloch,C.Avila,Readingcinnamonactivatesolfactorybrainregions, NeuroIm-age32(2006)906–912.
[36]H.Liepmann,DieLinkeHemisphäreanddasHandeln,MünchMedWschr49 Q4
(1905)2322–2326,2375–2378. 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461
