Figure 1.
Display sequence in the cued attention task. Each trial commenced with a fixation stimulus, followed by a cue: Spatial (arrow), Feature (colored square), or Neutral (gray square). The neutral cue was noninformative, whereas the spatial and the feature cues were fully informative. After a short blank (100 ms), a Landolt array appeared in which the target stimulus (full circle) was either present (50%) or absent (50%). In the example shown above, a red target occurs in the lower right quadrant (outlined in inset). On each trial, a 400 ms train of TMS was delivered randomly at either a low or high intensity, beginning 100 ms after cue onset. Online monitoring of gaze ensured that participants maintained fixation throughout the entire trial.