The Complication Experiment Uncomplicated

Early work on the complication experiment, which involved the subject judging the position of a moving pointer at the onset of an auditory signal, is reviewed. The traditional explanation in terms of the earlier processing of input in one modality (the prior entry hypothesis) is critically discussed and rejected. Two experiments are reported in which constant error is shown to vary as a function of the position at which the auditory signal was delivered and the direction of rotation of the pointer. A third experiment found that auditory signals of different intensities gave rise to errors of similar magnitude. Unlike other recent complication experiments, all three gave rise to predominantly anticlockwise constant error. This disagreement was resolved by a fourth experiment in which predominantly clockwise error was obtained by presenting the auditory signal on only one revolution per trial. An explanation, developed from models of absolute judgement tasks, is put forward to account for the present and earlier results in terms of subjects’ judgement strategy.