Visual search is a crucial, everyday activity that declines with ageing. Here, referring to the environmental support account, we hypothesised that semantic contextual associations between the target and the neighbouring objects (e.g., a teacup near a tea bag and a spoon), acting as external cues, may counteract this decline. Moreover, when searching for a target, viewers may encode information about the co-present distractor objects, by simply looking at them. In everyday life, where viewers often search for several targets within the same environment, such distractor objects may often become targets of future searches. Thus, we examined whether incidentally fixating a target during previous trials, when it was a distractor, may also modulate the impact of ageing on search performance. We used everyday object arrays on tables in a real room, where healthy young and older adults had to search sequentially for multiple objects across different trials within the same array. We showed that search was quicker (1) in young than older adults; (2) for targets surrounded by semantically associated objects than unassociated objects, but only in older adults; and (3) for incidentally fixated targets than for targets that were not fixated when they were distractors, with no differences between young and older adults. These results suggest that older viewers use both environmental support based on object semantic associations and object information incidentally encoded to enhance efficiency of real-world search, even in relatively simple environments. This reduces, but does not eliminate, search decline related to ageing.
Keywords: Visual search; ageing; incidental encoding; real environment; semantic contextual guidance.