Abstract
In visual backward masking, performance on a target is impeded by a following mask. In B-type masking, strongest masking occurs when the mask trails the target for about 30–80ms. To account for this century old result, all models propose an inhibitory interaction between mask and target based on their energy ratio. Here, we show strong counter-evidence to this proposition. We presented a vernier flanked by aligned verniers. Strongest B-type masking occurred when the flanks had the same length as the vernier. For longer (higher energy) and smaller (lower energy) flanks, performance improved. By further increasing the energy of the mask, we could even almost completely diminish masking. Hence, energy is not the key aspect in masking. We will suggest that the overall spatial layout of the mask is a much better factor to explain metacontrast masking.