Analysis time windows

“Stimulus onset” refers to the time at which the picture came on screen, and “articulation time” corresponds to the speech onset time for the verbal response. Data analysis was done in 256-ms windows, and the window before stimulus onset was chosen as the baseline. Windows were called stimulus aligned (SA) or articulation aligned (AA) based on whether the trial data in the window was aligned to the stimulus onset or articulation time, respectively. Windows are denoted as SA/AA: <start time > to <end time > in this article (Fig. 2). For example, AA: −256 to 0 ms represents a window that starts 256 ms before articulation. The 0-ms time has a dual meaning based on the context. It is used to represent stimulus onset in SA windows and articulation time in AA windows. All analyses were done in W = 52 windows, consisting of 11 SA (start times 0–320 ms, sliding by 32 ms) and 41 AA (start times −480 to 768 ms, sliding by 32 ms) windows.

SA windows are aligned to stimulus onset, AA to onset of articulation. The last SA window did not overlap with the first AA window, to ensure temporal continuity. 11 SA (start times 0–320 ms, sliding by 32 ms) and 41 AA (start times −480–768 ms, sliding by 32 ms) windows were used in analysis.