Resumen
The main aim of this work was to understand to what extent driving on a poor-quality surface requires more central, attentional resources than driving on a smooth surface. A dual-task experiment was devised in which participants were asked to perform two tasks concurrently: the first, main task was simulated driving. Participants drove on three kinds of surface: smooth, rough, and very rough, the surface quality defined according to the International Roughness Index. The second task was one of tone discrimination: participants listened to one of three possible tones of differing pitch and were asked to classify it verbally according to its pitch. Both Reaction Times and error rates were used. The following prediction was tested: if the quality of the road surface affects attentional resources while driving, then, as the quality of the road surface deteriorates, the interference which driving exerts on tone discrimination should increase. Results showed that, as the quality of the road surface worsened, RTs in the tone discrimination task tended to decrease and errors to increase. This finding is clearly of interest as regards safety: a functionally compromised surface not only affects the external, physical aspects of the driver/vehicle pair, but also the driver's cognitive level, with a potentially dangerous fall in accurate coping with driving at the same time, and on the monitoring and interpretation of sources of danger while driving. As results showed that surfaces of different qualities directly affect cognition, this work appears to be significant and involves socially useful developments.