The contribution of working memory to divided attention.
Previous studies have indicated that increasing working memory (WM) load can affect the attentional selection of signals originating from one object/location. Here we assessed whether WM load affects also the selection of multiple objects/locations (divided attention). Participants monitored either two object-categories (vs. one category; object-based divided attention) or two locations (vs. one location; space-based divided attention) while maintaining in WM either a variable number of objects (object-based WM load) or locations (space-based WM load). Behavioural results showed that WM load affected attentional performance irrespective of divided or focused attention. However, fMRI results showed that the activity associated with object-based divided attention increased linearly with increasing object-based WM load in the left and right intraparietal sulcus (IPS); while, in the same areas, activity associated with space-based divided attention was not affected by any type of WM load. These findings support the hypothesis that WM contributes to the maintenance of resource-demanding attentional sets in a domain-specific manner. Moreover, the dissociable impact of WM load on performance and brain activity suggests that increased IPS activation reflects a recruitment of additional, domain-specific processing resources that enable dual-task performance under conditions of high WM load and high attentional demand.
Department of Human and Educational Sciences, University of Perugia, Italy. valerio.santangelo@unipg.it
Valerio
V
Santangelo
Emiliano
E
Macaluso
D000328:Adult; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods; D005260:Female; D005556:Form Perception / Q000502:physiology; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult