Aphasiaisanimpairmentintheexpressionorcomprehensionoflanguagethatresultsfromstroke,traumatic brain injury orprogressive neurological disease. Approximately two millionpeople in the UnitedStates suffer fromaphasia,whichhasprofoundimpactsonqualityoflife,theabilitytoreturntoworkandparticipationinlife activities. Research has shown that speech-language therapy, the treatment for aphasia, can significantly improvepeople?sabilitytocommunicate.However,amajorlimitationinthefieldofaphasiarehabilitationisthe lackofpredictabilityinpatients?responsetotherapyandtheinabilitytotailortreatmenttoindividuals.Currently, aphasia treatments are selected largely based on patient?s language abilities and language deficits with little considerationoflearningability,whichwecalllearningphenotype.Learningphenotypehasbeenusedtoinform rehabilitation approaches in other domains but is not currently considered in aphasia. Our overarching hypothesis is that poor alignment of learning ability and language therapy limits progress for patients and presentsabarriertoindividualizingtreatment. Theobjectivesoftheproposedstudyareto(1)determinethelearningphenotypeofindividualswithaphasia, and (2) examine how lesion characteristics (size and location of damage to the brain), language ability and cognitiveabilityrelatetolearningability.Toaccomplishourobjectives,wewillmeasureimplicit(observational) andexplicit (rule-based) learningability inpeople withaphasiavia computer-based tasks. Regression models willbeusedtoexaminebrainandbehavioralfactorsthatrelatetolearningability. An in-depth characterization of learning in aphasia is important, as research has suggested that multiple learning systems exist. Furthermore, manipulations to stimuli, task, and feedback can lead to differential recruitment of learning systemsand unlock learningpotential,particularly in clinicalpopulations (Ashbyetal., 1998;?2002;?2003;?Ashby&O?Brien,2005;?Davis,Love,&Maddox,2009;?Knowltonetal.,1992;?Koenigetal., 2007;?Shohamyetal.,2004;?Squire&Knowlton,1995).Ourpriorworkinaphasiasupportsthehypothesisthat individuals with aphasia suffer from impaired learning mechanisms and are sensitive to task manipulations(Vallila-Rohter&Kiran,2013).ThesefindingsdemonstratethatthatPWAaresuccessfullearning in some conditions and not others and provides the rationale for the proposed series of studies focused on characterizinglearningabilitiesinindividualswithaphasia. The long-term goal of our research is to maximize rehabilitation outcomes for individuals with aphasia by aligninglearningabilitywithinterventionapproach.
Theproposedprojectisrelevanttopublichealthbecauseitisdesignedtoaddresstheimportantissue oflearningafteraphasia-inducingstroke.Speech-languagetherapyisthetreatmentforaphasia,andrelies heavilyonbehavioraltherapiesthatengagevaryingsystemsoflearning.Inordertobettertailortreatmentto individualsandmoreeffectivelypredictoutcomes,wemustequipclinicianswithwaystocharacterizelearning inindividualpatients,furtheridentifyinghowtherapyprotocolscanbealteredtomatchpatientlearningability.
