Task complexity as mediated by proficiency, working memory, and attention: Competition for cognitive resources during L2 oral task performance

[eng] Drawing on known language learning processes, principles behind language course syllabus design, and previous second language acquisition research, Long introduced the concept of task-based language teaching (TBLT) in 1985. Interest in TBLT has prompted research into the effects of task demands on the learning process. Interactive demands promote the negotiation of meaning between interlocutors and provide opportunities for uptake of corrective feedback from a teacher or fellow students. Cognitive demands can direct attention to primary aspects of the language ensuring successful task performance. Increasing cognitive demands builds on previously acquired access and automatization of speaking processes pushing learners to approach complex concepts with suitable speech. The advent of task-based language teaching included a call for establishing a set of criteria by which tasks could be graded and sequenced within a language learning syllabus. Tasks sequenced from simple to complex are believed to enhance the learning process by recreating ontological learning processes while benefiting from adults’ conceptual understanding of the world. This call has motivated research within the field of second language acquisition (SLA) to understand the influence that task design features have on language production and learning processes in order to develop the needed task sequencing criteria. Much research has focused on how cognitive resources are allocated to different aspects of speech within the bounds of two hypotheses which attempt to predict outcomes: The Trade-off Hypothesis (Skehan, 1998; Skehan & Foster, 2001) and the Cognition Hypothesis (Robinson 2001a, 2001b, 2003a, 2005). Conclusive results, however, have been elusive. The study of individual differences and the role that they play in language production and acquisition processes may provide some direction to researchers. The current dissertation proposes that learners of varying cognitive capacities would demonstrate trade-off effects between measures of linguistic complexity, accuracy and fluency at different points along a continuum of task complexity. In addition, where trade-offs were detected, it was predicted that subjects of higher cognitive capacity would demonstrate them more clearly. Five narrative tasks each representing different levels of cognitive complexity were performed by 47 subjects who were categorized according to high and low levels of proficiency, and attentional and working memory capacity. Repeated measures and correlational analyses did not provide support for the hypotheses although they do indicate that individual differences may play a role in communicative strategies that subjects use in order to meet task demands. [cat] L’any 1985, Long va introduir el concepte d’ensenyament basat en les tasques pedagogiques (TBLT) basant-se en els coneixements dels processos d’aprenentatge, en els fonaments del disseny dels plans d’estudis de cursos de llengues estrangeres i en la investigacio realitzada previament en l’ambit de l’adquisicio d’idiomes. El interes en TBLT ha motivat diverses investigacions sobre els efectes dels requisits de les tasques en els processos d’aprenentatge. Els requisits interactius fomenten un dialeg sobre aspectes de la llengua entre els interlocutors i proporcionen oportunitats per captar comentaris correctius del professor o altres estudiants. Els requisits cognitius d’una tasca poden orientar l’atencio d’un alumne als aspectes importants de la llengua, assegurant aixi un resultat satisfactori. Augmentant els requisits cognitius de les tasques permet consolidar processos com son els d’acces i d’automatitzacio de certs aspectes de la llengua. Aixo incentiva als alumnes a fer servir un llenguatge adequat al enfrontar-se a tasques complexes. L’aparicio de l’ensenyament basat en les tasques pedagogiques va incloure un reclam per establir un conjunt de criteris mitjancant els quals es podia graduar i sequenciar les tasques en un pla d’estudis. Es creu que sequenciar les tasques de simple a complexa millora el proces d’aprenentatge al recrear el proces de desenvolupament ontologic. Aquest reclam ha motivat investigacions en el camp de l’adquisicio d’idiomes estrangers (SLA) per entendre la influencia del disseny de les tasques sobre l’us i els processos d’aprenentatge dels idiomes amb la finalitat de desenvolupar els criteris. La investigacio s’ha centrat en com els recursos cognitius estan repartits entre els diferents aspectes de la parla dins els parametres de dos hipotesis: La Trade-off Hypothesis (Skehan, 1998; Skehan i Foster, 2001) i la Cognition Hypothesis (Robinson 2001a, 2001b, 2003a, 2005). Resultats concloents, malgrat tot, han estat elusius. L’estudi de les diferencies individuals i el paper que assumeixen en els processos de la parla i de l’adquisicio d’idiomes poden orientar als investigadors. La present dissertacio proposa que els aprenents amb capacitats cognitives diferents demostren efectes de trade-off (compensacio) entre mesures de complexitat linguistica, precisio gramatical i fluidesa amb resultats diferents. Quaranta set participants van completar cinc tasques narratives, cada una d’elles representativa d’un nivell de complexitat cognitiva diferent. Els participants van ser classificats segons el seus nivell de coneixement del idioma i de les seves capacitats d’atencio i de memoria de treball. Un analisi estadistic dels resultats no demostra les hipotesis com a certes malgrat que si que indica que les diferencies individuals poden influir en les estrategies comunicatives que els participants van utilitzar per completar la tasca.