Cover picture: Stimuli used to study orientation-selective pattern masking, superimposed on the EEG response. From left to right across the top row, a vertical "test" stimulus is increased in contrast over time. This stimulus is combined with fixed contrast maskers in the other rows. The test stimulus is harder to detect in combination with the parallel mask than with the orthogonal mask. In this study, the responses to the test and mask were distinguished by giving them different temporal frequency signatures. Infant and adult data were compared with normalization models of cortical processing. For details, see the article by Candy et al. in this issue (pages 4530-4541).