Abstract
Hierarchical letters are large letters built from smaller letters that represent global and local levels of information, respectively. This study examines whether multiple repeated exposures to hierarchical letters (MREs) can strengthen attentional control during multi-level item perception. Past literature indicates poor attentional control of global information during multi-level item perception: Irrelevant global information influences response times during local-focused processing; congruent global information (e.g., large A made of small A’s) speeds responding (global facilitation), whereas incongruent global information (e.g., large G made of small A’s) slows responding (global interference). An earlier study in our lab examined whether MREs could reduce global interference and found no reduction in global influence. The current study adjusts the design and examines whether MREs can reduce global facilitation, after MREs of incongruent global information. Trials began by assigning a relevant level and target letter, and then initiated a run of seven presentations. In each presentation within a run, participants saw one hierarchical letter and verified target letter presence at the relevant level. RTs were recorded. Critical runs consisted of one critical congruent stimulus letter and six incongruent letters; the congruent letter occurred at position 2 (1 exposures before it) or 6 (5 exposures before). A baseline condition containing only incongruent letters was used for comparisons against congruent letter RTs. Of particular interest was locally-focused trials. At position two, congruent letter RTs were faster than incongruent letter RTs, indicating global facilitation. At position six however, congruent and incongruent letter RTs were similar, exhibiting good attentional control of irrelevant global information. These results indicate that MREs can strengthen attentional control and reduce the influence of irrelevant global information. Lastly, these design changes and results imply that the type of irrelevant information presented in prior MREs influences attentional control; unfavorable information strengthens attentional control whereas favorable information does not.