Automaticity and attentional control in spoken language processing

A long-standing debate in the science of language is whether our capacity to process language draws on attentional resources, or whether some stages or types of this processing may be automatic. I review a series of experiments in which this issue was addressed by modulating the level of attention on the auditory input while recording event-related brain activity elicited by spoken linguistic stimuli. The overall results of these studies show that the language function does possess a certain degree of automaticity, which seems to apply to different types of information. It can be explained, at least in part, by robustness of strongly connected linguistic memory circuits in the brain that can activate fully even when attentional resources are low. At the same time, this automaticity is limited to the very first stages of linguistic processing (<200 ms from the point in time when the relevant information is available in the auditory input). Later processing steps are, in turn, more affected by attention modulation. These later steps, which possibly reflect a more in-depth, secondary processing or re-analysis and repair of incoming speech, therefore appear dependant on the amount of resources allocated to language. Full processing of spoken language may thus not be possible without allocating attentional resources to it; this allocation in itself may be triggered by the early automatic stages in the first place.