Theobjectiveoftheproposedprojectistoexaminehowvisualandvocalsocialrhythmicentrainmentscaffolds languagedevelopmentintypicallydevelopinginfantsandthoseatriskforautismspectrumdisorder(ASD). ASDisacommonandlifelongneurodevelopmentaldisordercharacterizedbyimpairmentsinsocial communicationandrepetitivebehaviors.Yet,thereisstrikingheterogeneityinlanguageacquisitioninchildren withASD.Additionally,languagedelaysinASDareoftenafirstconcernforparentsthattheirchildisnot developingasexpected.Elucidatingindividualdifferencesinlanguageacquisitionandpromotingmeaningful languagedevelopmentinASDisofutmostimportancebecauselanguageabilitiesarelinkedwithlong-term outcome.Intypicallydevelopinginfants,rhythmplaysacrucialroleinsocialcommunicationandlanguage development.Thisisexemplifiedbycaregivers?useofhighlyrhythmicinfant-directedspeechandsingingto attractandmaintaintheirinfants?attention.Infantsattendtorhythmatmultiplelevelsincludingtheacoustic speechsignal(e.g.,rhythmicstresscues)andthesocialinteractioninwhichspeechisembedded(e.g., rhythmicallycoordinatedeyegaze,gestures,vocalizations).Individualdifferencesinsocialrhythmsensitivity maybeamarkerofsocialattunementandserveasanimportantpredictorofindividualdifferencesinlanguage developmentinASD.ThisR21extendsourpriorworkdemonstratingrhythmicallyentrainedeyegazeintypical infantsandtoddlerstoinfantsat-riskforASDbyexaminingrhythmicsocialvisualengagementusingnovel eye-trackingparadigms(Aim1)andrhythmicsocialvocalengagementbasedonaninnovativemarkerof speechrhythms(Aim2).Moreover,weproposetoexaminewhethervisualandvocalsocialentrainment predictindividualdifferencesinlanguageacquisition(Aim3).ThisresearchiswellalignedwithNIDCD?sfocus onlanguageacquisitioninchildrenwithASD.Thesefindingsareexpectedtoprovidepreliminarydatatoguide futurelongitudinalinvestigationsofsocialentrainmentandlanguagedevelopmentinASD.Thisresearchmay leadtothedevelopmentofbiomarkersofrhythmicentrainmentthatmayinformearlyASDassessmentand diagnosis,aswellasinterventionstrategiesthat,ifwarranted,includerhythmandtimingofsocialinteractions asoneaspectofcomprehensivelanguageinterventionforthesechildren.
This project proposes that individual differences in visual and vocal social rhythmic entrainment, markers of social attunement, are associated with language development in typically developing infants and those at risk for autism spectrum disorder (ASD). A common and lifelong disorder characterized by social communication impairments, there is striking heterogeneity in language acquisition in ASD, which is associated with long-term outcome. This research will provide an important foundation for linking time-locked social entrainment to language skills with the potential to impact identification of early vulnerabilities for language delay and ASD, as well as the development of language intervention strategies incorporating rhythm and timing of social interaction.
