Participants drove their cats in an area with a relatively small number of constant inputs (like a residential area) or an area with a large amount of impacts (ie a crowded car park)
While doing this they listened to a pre-recorded tape containing a series of numbers that changed from one sequence to the next
Results
Participants made more mistakes on the task in the car park than in the residential area
This could be explained by cognitive overload theory as they are giving more attention to the stimuli of driving than listening to numbers