Delogu, F. , Nijboer, T. & Postma, A.
Experimental Psychology, Helmholtz Institute, Utrecht University, the Netherlands
Information about where and when events happened seem naturally linked to each other, but only few studies have investigated if and how they become associated in working memory. We tested whether the location of item and their temporal order are jointly or independently encoded. We also verified if spatio-temporal interactions change according to the sensory modality of items. In two experiments, participants memorized sequences of five environmental sounds (exp.1) and pictures (exp.2) originating from five different locations. They were asked to recall either their position or temporal order. Attention during encoding was manipulated by contrasting blocks containing different percentages of spatial and temporal trials. Results indicate that temporal and spatial encoding is more effective when attention is focused on the target dimension. Interesting differences between modalities also emerged. In the auditory modality, while temporal order recall was linearly affected by the simultaneous encoding of item location, position recall was mostly unaffected by a concurrent memory load. In vision, the recall of both temporal and spatial information was strongly affected by attention. We conclude that temporal order and spatial encoding are conducted by separate mechanisms and that the strength of their association is modulated by the modality of the input.