Strijkers, K. 1, 3 , Holcomb, P. 2 & Costa, A. 3
1 Universitat de Barcelona
2 Tufts University
3 Universitat Pompeu Fabra
In a highly dynamical structure as the brain, top-down modulations in function of our intentions become crucial to produce meaningful behavior. However, the exact nature of feedback projections remains contentious, especially in complex functioning as language. Here we explored the role of top-down intention for accessing words in speech production by comparing the brain’s electrical response to word frequency during object naming and during non-verbal object categorization. We found that during naming, the event-related potentials (ERPs) elicited for objects with low frequency names started to diverge from those with high frequency names as early as 152 ms after stimulus onset, while during non-verbal categorization the same frequency comparison appeared some 200 ms later. Contrary to reactive top-down accounts and the dominant view in language production, the data demonstrate that top-down intention drives the ignition of task-relevant cortical activity related to words. Besides putting serious constraints on the current speech production models, these findings also extent recent evidence regarding the proactive role of feedback projections in the study of vision to more complex and natural human behavior we practice on a daily basis. Furthermore, it sets the stage, both in terms of methodological tools as theoretical framework, for exploring novel and intriguing questions in monolingual and bilingual speech production.