Pinging the brain to reveal the hidden attentional priority map

Priority maps are winner-take-all neural mechanisms that are thought to guide the allocation of attention. Within these maps, attentional priority is coded as weights on a topographic representation of physical space. Research has shown that these weights are not just influenced by the current stimuli presented but also by selection episodes that occurred in the past – called selection history. The current study demonstrates, for the first time, that these latent, implicitly-learned spatial biases can be visualized by ‘pinging’ the brain (a technique previously used to study activity-silent working memory). By briefly flashing high-contrast, task-irrelevant visual stimuli in the inter-stimulus interval between searches, participants’ current history-trained latent attentional priority could be decoded via scalp encephalography. Our findings not only offer a novel method of visualizing this latent attentional priority map, but also shed light on the underlying mechanisms allowing our past experiences to influence future behaviour.