Speed and accuracy effects of fingers and dexterity in 5-choice reaction tasks.

In two experiments we studied the influence of dexterity (controls, typists, pianists) and of differences between the five fingers of the dominant hand on speed and accuracy in a 5-choice reaction task. We used five coloured squares (Blue, Green, Yellow, Red, White) as stimuli, randomly varying foreperiods (3-10s) and an intermediate stimulus-response-compatibility. The results reported here were independent of sex, foreperiods, and colour of stimuli. In Experiment 1 (N = 168) with three groups (controls, typists, pianists) thumb and little finger showed significantly shorter reaction times than did index, middle, and ring finger. This difference did not interact with dexterity. Averaged across all the fingers typists and controls did not differ. Pianists showed significantly shorter reaction times than these two groups. Experiment 2 (N = 40) replicated all these findings. In both experiments groups did not differ in speed-accuracy-trade-off. The accuracy of the fingers was independent of dexterity. In all three groups the little finger showed the lowest rate of false alarms and the highest degree of reliability. The frequency distribution of finger confusions in all groups was in accordance with the spatial proximity of fingers: the closer their proximity the higher were the rates of confusion. In addition, these distributions showed an asymmetry across all three groups. The finger next to the 'correct' finger in direction towards the thumb showed the highest false alarm rate in each case.