Implicit memory guides the allocation of attention in time: Evidence from intertrial priming

Attention can be allocated in time as well as in space. Previous studies have shown that repetition of target spatial position speeds visual search performance (Maljkovic & Nakayama, 1996), suggesting that spatial positions encoded in implicit memory guide attention. Here, we investigated whether repetition of the position of a target in time also speeds search. Observers had to look for a uniquely colored digit within an RSVP stream of uniformly colored digits and to respond to its value. Reaction times were faster when on two consecutive trials the target happened to appear at similar than at different temporal positions. This effect was eliminated when the expectations regarding the temporal position of the upcoming target were high. This novel temporal position priming effect suggests that implicit short term memory of temporal representations guides the allocation of attention in time, similarly to the way memory traces of spatial representations guide attention in space.