Figure 2.

A continuous task designed to preclude general attentional settings associated with the onset of the display. (A) Example stimulus display: participants make sequential responses, working from left to right, top to bottom, indicating whether each item in the display is a letter or a digit. The display remains onscreen throughout the response sequence. The distractor appears briefly during a minority of displays, and never co-occurs with the responses immediately following the display onset. (B) Despite being entirely irrelevant to the task in terms of visual appearance, meaning, location, and any attentional settings, the brief presentation of a distractor produces significant RT slowing for the response immediately following its presentation (lag 0), and for the two subsequent responses (lags 1 and 2).