Hello Michael, can you clarify a portion of what you have said?
Note that this time bears no relationship to when the key was actually pressed. If the wait period was, say, 1900 ms, regardless of the key actually being pressed at 200 ms, your measured RT value will be slightly later than 1900 ms, as you are measuring when the keypress was processed, not when it occurred.
Does this mean the RT cannot be reasonably “restored”? For example, if there was a trial where the RT was faultily recorded as 2000ms but I knew for certain that the wait period was exactly 1900ms, could I conclude that the RT was 100ms? Or is the margin of error in the delayed processing simply too great?