PAO                     Percentage Above Optimal (PAO) path as a
                        measure of organization in a foraging task.
Q.score                 Q score for foraging efficiency.
best.r                  Best-r index for foraging organization
meanITD                 Mean Intertarget Distance (ITD) from x and y
                        coordinates for target positions.
number.intersections    Counter for the number of intersections of
                        non-consecutive trajectories between targets
                        among a scanpath in a foraging task.
