The efficiency of different cue types for reducing spatial-frequency uncertainty.

Detection experiments reveal that performance is decreased when the signal's spatial frequency varies unpredictably across trials compared with conditions where it is held constant. However, this effect can more or less be compensated by presenting cues shortly before each trial. To investigate the efficiency of different sensory and symbolic cue types a signal-detection experiment with spatial-frequency uncertainty was carried out. The inter-stimulus interval between cue and signal as well as for the sensory cue types, the spatial overlap between cue and signal, was varied. The results reveal appreciable efficiency differences. While some cues were only of little help, others reduced uncertainty almost entirely. However, the efficiency of cues which were identical to the signals was severely restricted by forward-masking effects when they were presented at the same position as the signal.