Descripción del proyecto
IMPAIRMENTS OF LANGUAGE DEVELOPMENT OFTEN CO-OCCUR WITH MOTOR DEFICITS. THE SOURCE OF THIS CO-OCCURRENCE IS NEVERTHELESS FAR FROM UNDERSTOOD. THE CURRENT PROJECT AIMS AT THIS UNDERSTANDING. CURRENT THEORETICAL MODELS ACKNOWLEDGE AN IMPORTANT ROLE OF AUDIOMOTOR INTEGRATION IN SPEECH PERCEPTION. THIS MECHANISM COULD PARTLY EXPLAIN THE LINK BETWEEN MOTOR FUNCTION AND LEARNING OF WORD FORMS BUT NOT THE DEFICITS IN SYNTACTIC LEARNING THAT OFTEN ACCOMPANY DEVELOPMENTAL LANGUAGE IMPAIRMENTS. THE ACCUMULATED EVIDENCE FROM DIFFERENT LINES OF RESEARCH (MUSIC, RHYTHM PROCESSING) SUPPORT A ROLE OF THE MOTOR SYSTEM IN TEMPORAL PROCESSING AND IN PARTICULAR IN RHYTHM WHILE, IN PARALLEL, ALTERED RHYTHM PERCEPTION IS DOCUMENTED IN MANY LANGUAGE DEVELOPMENT IMPAIRMENTS (I.E. DYSLEXIA, COCHLEAR IMPLANTS, SPECIFIC LANGUAGE IMPAIRMENT). SINCE RHYTHM IS A CORE PROPERTY OF SPEECH AND IT INFLUENCES BOTH SPEECH PERCEPTION AND GRAMMATICAL PROCESSING, THIS FUNCTION CAN BE A PLAUSIBLE INFLUENCE OF THE MOTOR SYSTEM ON BOTH WORD AND RULE LEARNING IN LANGUAGE. THE CURRENT PROJECT AIMS AT TESTING THIS LINK SPECIFYING THE MECHANISMS AND BRAIN REGIONS INVOLVED IN THIS INTERACTION. THIS SHOULD HELP TO IMPROVE SPECIFICATION OF CURRENT MODELS OF LANGUAGE PROCESSING. IN ORDER TO REACH THIS GOAL WE DEVELOP FIVE STUDIES THAT WILL FOCUS IN THREE OBJECTIVES THAT SHOULD CLARIFY THIS LINK. FIRST, WE AIM TO ELUCIDATE THE BROADER MOTOR NETWORK INVOLVED OUTSIDE THE MOTOR CORTEX AND THE SPECIFIC ROLE OF THE CONNECTIONS WITHIN THE NETWORK IN LL. SECOND, WE AIM AT UNCOVERING THE RELATION BETWEEN MOTOR SYSTEM DEVELOPMENT, RHYTHM PERCEPTION AND LANGUAGE ACQUISITION IN EARLY DEVELOPMENT. THIRD, SINCE LANGUAGE IMPAIRMENT ARE MORE OFTEN OBSERVED IN MALES THAN FEMALES A TRANSVERSAL GOAL OF THE PROJECT IS TO UNDERSTAND THE HOW GENDER CAN INFLUENCE THIS PHENOMENON. THE PROJECT WILL DEVELOP A NEW PROTOCOL THAT ALLOWS TO TEASE APART ENDOGENOUS AND EXOGENOUS EFFECTS OF RHYTHMIC TEMPORAL ORIENTING AND HOW THEY INFLUENCE LEARNING OF NON-ADJACENT DEPENDENCIES IN LANGUAGE, THAT ARE AT THE CORE OF SYNTACTIC LEARNING IN LANGUAGE. ADULTS WILL BE ASSESSED WITH EEG AND MRI TO ASSESS FOR THE DIFFERENT MECHANISMS INVOLVED AND THEIR RELATION WITH DIFFERENT PARTS OF THE MOTOR NETWORK. 24 MONTHS-OLD INFANTS WILL BE ASSESSED WITH A SIMILAR PROTOCOL ALLOWING TO OBSERVED THE POSSIBLE DEVELOPMENTAL DIFFERENCES IN THE PROCESSING OF EXOGENOUS AND ENDOGENOUS COMPONENTS OF RHYTHM. MRIS AVAILABLE FROM A NEONATAL ASSESSMENT WILL ALLOW STUDYING THE EXPLANATORY VARIANCE GIVEN BY THE EARLY CONNECTIVITY OF THE DISTINCT PARTS OF THE NETWORK (NAMELY CORTICAL VS SUBCORTICAL CONNECTIONS). GENDER DIFFERENCES WILL BE ANALYZED IN THE DIFFERENT STUDIES AND IN THE RE-ANALYSES OF SEVERAL STUDIES PREVIOUSLY COLLECTED IN OUR GROUP. UNDERSTANDING THE BASIC ROLE OF THE MOTOR SYSTEM IN LANGUAGE LEARNING IS REQUIRED TO ADDRESS PLAUSIBLE TARGETS FOR INTERVENTION AND PREVENTION OF DEVELOPMENTAL LANGUAGE DISORDERS, AND TO ADVANCE IN OUR KNOWLEDGE OF A BROADER AND MORE ESSENTIAL ROLE OF THE MOTOR SYSTEM IN LANGUAGE LEARNING. PRENDIZAJE DEL LENGUAJE\PROCESAMIENTO TEMPORAL\SISTEMA MOTOR\EEG\RESONANCIA MAGNETICA