Encoding into Visual Working Memory: Event-Related Brain Potentials Reflect Automatic Processing of Seemingly Redundant Information

Figure 1

Patterns presented as stimulus material in the S1-S2 memory comparison task. Sixteen five-dot patterns were applied in the present study as S1 and S2. According to the transformation rules (i.e., rotation or mirroring on a diagonal), these patterns are divided into four different sets consisting of four equivalent patterns (equivalence sets (ESs)). The different sets of equivalent patterns can consist either of four or of eight patterns and, therefore, have an ES size (ESS) of either four or eight. In the present study, two ESS 4 and two ESS 8 sets were applied; from the ESS 8 sets, four patterns were selected to serve as stimulus material. In addition, with regard to [14, 16], the individual patterns differ in rated complexity (see right column). In the present study, one ES with low and one with high averaged complexity ratings of each set size were applied.