Individual differences in metacontrast masking: A call for caution when interpreting group data

In this issue of Consciousness and Cognition, Bachmann (2010) comments on our study (Albrecht, Klapötke, & Mattler, 2010), which revealed two groups of observers with qualitative individual differences in metacontrast masking that are enhanced by perceptual learning. We are pleased that our study receives this attention and even more about Bachmann’s extremely positive comments. In this invited reply we argue that observers seem to be similar only at the beginning of the experiment but they have no choice as to which group to join. Findings strongly recommend to look at the data of individual subjects.