Sub-components’ Differential Functions of Working Memory during Visual Search : An fMRI Study

The sub-components of working memory(WM) function differently during visual search task, respectively. Previous behavioral studies have shown that visual WM(VWM) worked efficiently on the visual search but executive WM(EWM) did not work on it. The model of prefrontal cortex(PFC) based on the type of processing might explain these different effects. This study examined selective brain activation in VWM and EWM during visual search task using functional Magnetic Resonance Imaging(fMRI) techniques. This study found that the load of VWM during visual search task activated left ventrolateral PFC(VLPFC, BA 45) and inferior temporal cortex(ITC, BA 19/37), but the load of EWM activated bilateral dorsolateral PFC(DLPFC, BA 9/46) and posterior parietal cortex(PPC, BA 7/19). The results suggested that differential effects of the two sub-components of WM on visual search would be explained by the functional dissociation of VLPFC and DLPFC in frontal region and of ITC and PPC in posterior region.