Abstract
Concurrent working memory (WM) load increased the interference by visual distractors during a selective attention task (de Fockert, Rees, Frith, and Lavie, 2001). However, recent studies showed that the different types of WM load can produce different effects depending on whether the load overlaps with the target or the distractor processing (Kim, Kim, & Chun, 2005; Park, Kim, & Chun, 2005). In this study, functional magnetic resonance imaging (fMRI) was used to examine whether WM load decreases distractor processing when the two overlap. Participants were asked to classify famous written names as athletes or politicians while ignoring distractor faces during a selective attention task, with holding a famous face (low WM load condition) or an unfamiliar face (high WM load condition) in WM. Activities in the frontal cortex area increased during the high WM conditions, but the occipital and temporal cortex areas showed more activation when WM load was low. More interestingly, high WM load decreased face-related activity in the fusiform face area (FFA) when the contents of WM were faces. These results suggest that dissociable systems for different types of contents have their own independent attentional capacity and that the same content-specific system subserves both WM and attentional selection.
This research was supported by Korean Ministry of Science & Technology 21st Century Frontier Research Program Brain Research Center Grant M103KV010021-05K2201-02110