Spoken word processing creates a lexical bottleneck

We report three experiments that examined whether presentation of a spoken word creates an attentional bottleneck associated with lexical processing in the absence of a response to that word. A spoken word and a visual stimulus were presented in quick succession, but only the visual stimulus demanded a response. Response times to the visual stimulus increased as the lag between it and the spoken word decreased, suggesting a bottleneck in processing. This effect was modulated by the uniqueness point of the spoken word; bottleneck effects were strongest when the spoken word had a late uniqueness point (Experiment 1). The effect was also modulated by the nature of the second task, with the effect stronger when the visual stimulus was a word rather than a shape (Experiment 2) or face (Experiment 3). Word processing appears to create a transient lexical bottleneck that is driven by the magnitude of lexical activity.