The authors concluded that while repetitive selection of one feature facilitates further selection of that feature (similar to continuously selecting ‘S’ over ‘W’ in Lambert et al., 1999), second-order relationships between features (i.e., multiple rules in the form of ‘‘if green then left’’) are not possible. It is worth noting that the type of learning reported by (Kristjánsson et al., 2001; Kristjánsson & Nakayama, 2003; for a review, see Kristjánsson, 2006) emerged quite rapidly and within a few trials. This time frame may not be sufficient for higher-order learning or its impact on attention.