Orienting attention to faces or scenes in working memory

Recent studies demonstrated that it is not only possible to orient attention in the extrapersonal world, but also to attend selectively to locations or items held as mental representations in working memory. Direct comparisons of attentional orienting in the perceptual and working-memory domains so far have revealed strong similarities in behavioural effects as well as in the neural systems involved in controlling the two processes. In the present experiment, we investigated if orienting attention to items held in working memory can modulate activity in functionally specialised brain areas involved in coding and maintaining those items, in an analogous way to how attentional orienting in the perceptual domain can modulate perceptual analysis. In each trial, participants memorised a face and a scene stimulus. During the retention interval, two successive cues instructed the participant to focus attention on the face or the scene. The second cue instructed participants to maintain attention on the same item or switch attention to the other item. At the end of the trial, a probe stimulus appeared, and participants decided if it matched the cued item. Event-related fMRI was used to measure the hemodynamic responses elicited by cues and during the subsequent retention intervals. Cue-related analysis revealed a frontoparietal network similar to that reported in previous experiments of attentional orienting in the perceptual and working-memory domains. Analysis of brain activity during the retention period following the orienting retro-cues showed modulation in brain areas involved in processing face and scene stimuli selectively, such as the posterior fusiform and the parahippocampal region respectively