No difference in prior representations of what to attend and what to ignore

Abstract

ABSTRACT Adaptive behaviour requires the selection of relevant, and the ignoring of irrelevant visual information. Previous work has shown that prior information about target (i.e., relevant) and non-target (i.e., irrelevant) objects facilitates such selection, presumably by enabling observers to create a working memory template for or against such objects. Using a cued visual search task, here we aimed to investigate whether, and how, target and non-target templates differ in terms of neural representation, as measured through fMRI activity patterns. Two hypotheses were tested: (1) while target representations are activated, non-target representations are suppressed prior to search, and thus these representations differ, and (2) target and non-target templates share similar initial representations but involve different control signals in anticipation of, or upon encountering the search display. Behaviourally, both target and non-target cues facilitated search compared to baseline. Using multivariate pattern and representational similarity analyses, the findings revealed little support for the suppression hypothesis. Posterior brain regions primarily coded for the category content of the template and did so similarly for target and non-target information. Frontal cortical areas, particularly the lateral prefrontal cortex and frontal eye fields, instead showed sensitivity to the status of the template, regardless of the object category it belonged to. These results are most consistent with the hypothesis that prior to selection, target and non-target information are represented similarly in terms of content, but differ in terms of the associated control signals.