Figure 2. The Visual Interference Method Illustrated for an Example Study.

Note. (A) The method compares the reaction time distribution to a target (here a peripheral black dot) in the absence (top row) and presence (bottom row) of a visual signal, here a task-irrelevant peripheral white distractor. (B) Example RT distributions obtained from one participant in the target alone condition (grey) and when the signal onsets after the target (thick black curve), with a Stimulus Onset Asynchrony (SOA) of 40 ms and stays on for 50 ms. The thin black curve shows the very rare errors. The blue dot indicates the dip onset time, that is, the time at which the signal-present RT distribution (black) starts diverging from the no-signal RT distribution (grey), as a result of the signal onset. The red dot indicates the time of maximum distraction ratio, which is not functionally meaningful, but is used as a starting point when moving backward in time to estimate the dip onset time. The visuomotor deadtime (T₀) is given by the time delay between the signal onset and the dip onset (70 ms in this example). RT = reaction time. Adapted from “Saccadic inhibition reveals the timing of automatic and voluntary signals in the human brain,” by A. Bompas, and P. Sumner, 2011, The Journal of Neuroscience, 31(35), pp. 12501–12512 (https://doi.org/10.1523/JNEUROSCI.2234-11.2011). See the online article for the color version of this figure.