Does explaining a visual guidance system affect visual attention distribution? I'm working on a driving simulator that uses an eyetracker to monitor the users gaze behavior. Based on a study I modeled an optimal scanpath that the users should follow in order to best maneuver through curves. If the users gaze hasn't hit certain AoIs in time, a visual cue is being shown to manipulate the user to include this point in his scanpath.

My question is, should I explain the meaning of the cues and the system behind them to the testers? Wouldn't that bias their scanning behavior?
Whether you tell them is going to depend on what you are trying to accomplish. What is the nature of the cues? If they capture strictly exogenous attention, what you tell won't affect how they allocate their attention because orienting is completely involuntary. However, if the cues involve your participants having to decide to redirect their attention, explaining it to them will affect how they allocate their attention and will likely lead to them relying more on your cues.