Driving performance was defined by lateral deviation, in other words how well they stayed in the center of the lane. While dial performance was based on the time in which it took to dial a correct sequence of numbers. Participants were given a practice period where they could learn the layout of the phone and vehicle. This was done to minimize the effect of learning on performance; meaning if they performed badly during dual task performance it was not due to unfamiliarity with the phone. The experiment began with two single task conditions, dialing and driving. The dialing task was judged by entering the correct sequence of numbers into the phone, which was then timed. This was built in to create a “speed-accuracy tradeoff” hopefully reducing the amount of errors when dialing the phone. The driving task was preformed at two speeds 35 mph and 55 mph. Participants were told to keep the car as close to the center of the lane as possible. At the end of each trial they were shown their mean error of lateral deviation. The dual task conditions consisted of the same two single task positions but as soon as the car was centered in the lane participants were instructed to type in the sequence until they correctly entered the number. Participants were instructed to either focus on minimizing dial time or lateral deviation. At the end of each trial participants received feedback aimed at the primary objective for each trial, and not the secondary task. Participants completed two, forty trial blocks, in which either dial time or lateral deviation was the objective. Driving speed was also counterbalanced between
Driving performance was defined by lateral deviation, in other words how well they stayed in the center of the lane. While dial performance was based on the time in which it took to dial a correct sequence of numbers. Participants were given a practice period where they could learn the layout of the phone and vehicle. This was done to minimize the effect of learning on performance; meaning if they performed badly during dual task performance it was not due to unfamiliarity with the phone. The experiment began with two single task conditions, dialing and driving. The dialing task was judged by entering the correct sequence of numbers into the phone, which was then timed. This was built in to create a “speed-accuracy tradeoff” hopefully reducing the amount of errors when dialing the phone. The driving task was preformed at two speeds 35 mph and 55 mph. Participants were told to keep the car as close to the center of the lane as possible. At the end of each trial they were shown their mean error of lateral deviation. The dual task conditions consisted of the same two single task positions but as soon as the car was centered in the lane participants were instructed to type in the sequence until they correctly entered the number. Participants were instructed to either focus on minimizing dial time or lateral deviation. At the end of each trial participants received feedback aimed at the primary objective for each trial, and not the secondary task. Participants completed two, forty trial blocks, in which either dial time or lateral deviation was the objective. Driving speed was also counterbalanced between