Contextual History Guides Spatial Attention During Search

Humans flexibly allocate attention depending on the given context. The dominant view posits that attention is guided by spatial and temporal sensory contextual cues that directly specify the target location. In real-world scenarios, however, such contextual cues are not always accessible, posing a problem for identifying the current context. Here, using a visual search paradigm combined with eye movement measurement, we show that humans also rely on the history of the previous context to infer the most probable context for guiding attention proactively. Participants searched for a visual target among the distractors. On one side of the display, targets were consistently associated with a particular fixed distractor configuration (Repeated condition), while on the other side, targets appeared with non-repeated, novel configurations (Novel condition). The Repeated condition represented a highly probable context, while the Novel condition represented rare contexts. Regardless of the current condition, participants’ initial saccade was biased toward the target direction of the Repeated condition, showing attentional guidance toward the location indicated by the most encountered context. Importantly, this attentional bias already existed before the onset of the search display, indicating the proactive use of contextual history to guide attention. We confirm that the probability of the target location or the movement parameters to report the target could not explain this context-history bias. Our study shows that, together with the sensory cue-based context detection mechanism, the context-history is also proactively used to robustly guide attention in the yet-unknown forthcoming context.