Bilingualsconstantlyexerciselanguagecontrol,aformofcognitivecontrol,bysuccessfullymanaging activationoftwolanguages,switchingbetweenthematwill,whileavoidingswitchingbymistake.Both languageandcognitivecontrolmaydeclineinaging,andagrowingbodyofevidencesuggeststhatstandard approachestoneuropsychologicalassessmentofbilingualscanresultininaccuratediagnoses.Aprominent theorysuggeststhatbilingualsrelyoninhibitiontoachieveefficientlanguagecontrol.Considerabledata supportthisclaiminspeechproductionandinyoungbilinguals,butlimitedresearchcharacterizestheroleof inhibitioninbilinguallanguagecomprehension,andhowinhibitorycontrolmechanismsmaychangeinaging bilinguals.Wehypothesizethatbilingualsrelyoninhibitionbroadly,inbothmodalities,andthatdomaingeneral inhibition,whichdeclinesinaging,underliesbilinguallanguagecontrol.Studiestodatemayhavefailedto revealinhibitorycontrolmechanismsbyuseofrelativelysimpletasks,measureswithlimitedsensitivity,and paradigmsthatdonoteffectivelyelicitinhibitorycontrol.Mostresearchonbilinguallanguagecontrolhas focusedonbehavioralresponsesinyoungbilingualsproducingout-of-context(e.g.,singlepicturenaming)or limitedcontextspeech(e.g.,singlesentences).
In Aim1, weexaminetheneuralcorrelatesofbilingual paragraphreading,toexaminethepossibleroleofinhibitionindefaultlanguageselectionduring comprehensionofshortstorieswithlanguageswitches,ataskthatresemblesnaturalisticlanguage comprehensionmorethanpreviouslystudiedtasks.WehypothesizefMRIwillrevealactivationofbrainregions commonlyassociatedwithinhibition(DLPFC,ACC)inaconditionthatrequiresbilingualstoselectthe nondominantlanguageasdefaultwhenprocessingoccasionalswitchestothedominantlanguage,andpredict changesinactivationinyoungversusolderbilinguals,whosebrainswillneedtocompensateforinefficiencyof inhibitorycontrolmechanisms.
In Aim2, weexaminepossibleoverlapbetweenlanguageandcognitivecontrol byinvestigatingthepossibilityofaging-relateddeclineinapowerfulbehavioralsignatureofinhibitorycontrol, i.e.,fullyreversedlanguagedominanceeffects,usingaversionofthecuedpicture-namingtaskthatwe recentlyidentifiedtoconsistentlyexhibitreverseddominanceeffectswithrepetition.Wehypothesizethistask willrevealaging-relateddeclineinabilitytoinhibitthedominantlanguage.Theproposedstudieswillexamine theintersectionofbilinguallanguageprocessingandagingtodeveloptheoreticalmodelsofcognitive processinginbilinguals,andtoincreaseinformationabouthowbilingualismaffectscognitivetestperformance, whichisnecessaryforearlyidentificationofcognitiveimpairmentwiththegoalofdelaying,slowing,orpossibly reversingcognitivedeclineinaginganddementia.Finally,thisresearchprojectwillenhancetheapplicant?s graduateschooltrainingandwillleadtoasuccessfulcareerasaneuropsychologisttrainedinimagingand agingresearch,withaspecialfocusonbilingualismwhichisoftencorrelatedwithminoritystatusintheUSA.

Public Health Relevance

Understandingthepatternsofcognitiveaging,whichappeartobedifferentinbilingualindividuals,isimportant forimprovingcognitiveassessmentofthegrowingnumberofagingbilingualsandforeventuallyslowing, delaying,orreversingcognitivedecline.Accordingtosomeaccounts,inhibitorycontrol?ortheabilityto preventirrelevantinformationfromdetractingfromcognitiveperformance?declineswithageandmayalso impactbilinguals?abilitytoeffectivelycontrolactivationoftheirtwolanguages.Theproposedresearchwill advancepublichealthgoalsbyelucidatingtheneuralandcognitivemechanismsofage-relateddeclinein inhibitorycontrol,andhowthisdeclinemayaffectlanguageperformanceofbilingualindividuals.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31AG058379-02
Application #
9615835
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Wagster, Molly V
Project Start
2018-01-01
Project End
2020-12-31
Budget Start
2019-01-01
Budget End
2020-12-31
Support Year
2
Fiscal Year
2019
Total Cost
Indirect Cost
Name
University of California, San Diego
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
804355790
City
La Jolla
State
CA
Country
United States
Zip Code
92093