A direct comparison of attentional orienting to spatial and temporal positions in visual working memory

Different visual attributes effectively guide attention to specific items in visual working memory (VWM), ensuring that particularly important memory contents are readily available. Predictable temporal structures contribute to this efficient use of VWM: items are prospectively prioritized when they are expected to be needed. Occasionally, however, visual events only gain relevance through their timing after they have passed. We investigated retrospective attentional orienting based on temporal position by directly comparing it with orienting to spatial locations, which is typically considered the most powerful selection mechanism. In a colour-change-detection task, in which items appeared sequentially at different locations, symbolic number cues validly indicated the temporal or spatial location of the upcoming probe item either before encoding (precues; Experiment 1) or during maintenance (retrocues; Experiments 1-3). Temporal and spatial cues were physically identical and only differed in their mapping onto either temporal or spatial positions. Predictive cues yielded cueing benefits (i.e., higher accuracy and shorter reaction times) as compared with neutral cues, with larger benefits for precues than for retrocues. Importantly, spatial and temporal cueing benefits did not differ. Equivalent retrocueing benefits were also observed across different cue-probe intervals and irrespective of whether spatial or temporal position was used as retrieval cue, indicating that items were directly bound to temporal position and not prioritized via a space-based mechanism. These findings show that spatial and temporal properties can be used equally well to flexibly prioritise representations held in VWM and they highlight the functional similarities of space and time in VWM.