The Effects of Cuing on the Detection of Bilateral Symmetry

Pashler (1990) demonstrated that detection of mirror symmetry can be facilitated by precuing the symmetry axis orientation with a line. In Experiment 1, Pashler's result of a valid pre-cuing benefit was repeated, but it was also shown that invalid cuing produces performance costs, relative to a non-informative cue. Experiment 2 showed that the effect is not purely visual because the letters "V" and "H" can produce the same valid and invalid cuing effects. In Experiments 3A and 3B, cue and pattern locations were varied, both absolutely and relative to each other. The results support an explanation for Pashler's atypical finding that horizontal symmetry can be detected faster than vertical symmetry. They also showed that the cuing effect is not local, contrary to Pashler's conclusion, but global and hence functionally useful.