Method and arrangement for interpreting a subjects head and eye activity

A method for hierarchically analyzing ocular then head orientation characteristics of a driver of a vehicle in order to identify locations of driver interest while driving the vehicle, said method comprising:

• detecting, utilizing an optical sensor, and quantifying a position and orientation of a presently driving driver's head relative to an interior space within a passenger compartment of a vehicle and also simultaneously detecting, when visible to the sensor, driver ocular orientation;
• providing a reference-base position of a reference driver's head relative to the interior space within the passenger compartment of the vehicle together with probable locations of driver interest correlated to different (1) ocular orientations and (2) head orientations relative the reference-base position of the reference driver's head;
• and
• normalizing said quantification of the position of the driver's head to said reference-base position and hierarchically comparing the quantified (1) driver ocular orientation when available, or the quantified (2) driver head orientation if quantified driver ocular orientation is not available, against the correlated probable locations of driver interest relative the reference driver's head and thereby enabling deducement of a corresponding probable location of driver interest based on the quantified orientation of either (1) the driver's ocular orientation or (2) the driver head orientation.