Abstract
Most research on mental efforts is done with tasks which demand for much attention and include conscious information processing. In that case a diversion task, drugs or alcohol should certainly show a deterioration in performance. The hypothesis for this study that another result should be obtained when more experienced tasks were used, is studied. On a bicyle simulator on which test persons have to balance and have to follow an unpredictable direction both aspects are combined. The test method and the test results are presented.