More efficient shielding for internal than external attention? Evidence from asymmetrical switch costs.

At present, the process of switching attention between external stimuli and internal representations is not well understood. To address this, Verschooren, Liefooghe, Brass, and Pourtois (2019) recently designed a novel paradigm where participants were cued to switch attention between external and internal information on a trial-by-trial basis. The authors observed an asymmetrical switch cost, which was larger when switching toward internal than external material, even though participants performed internal trials faster. In the current study, we sought to establish the cause of this asymmetry by adjudicating among predictions from three theoretical accounts: associative interference, priming, and memory retrieval. After replicating the original asymmetry (Experiment 1), we demonstrated that trial-by-trial carryover of attentional settings is not a necessary precondition (Experiment 2). The results from Experiment 3 indicate that the cost asymmetry can be best explained by an associative interference account, against a memory retrieval one. Together, these results therefor provide evidence in favor of an associative interference account and document that shielding attention for internal representations from external intrusions is more efficient than the other way around. This finding advances our understanding of a core aspect of cognitive flexibility and the relationship between external and internal attention. More research on this question and novel ones raised by it are necessary, however. (PsycInfo Database Record (c) 2020 APA, all rights reserved).