The Neural Correlates of the Retrieval of Previously Acquired Information During Top-down Control

Objective: To explore the neural correlates of the retrieval of previously acquired information during topdown control. Methods: T2*-weighted echoplanar imaging sequences (24 axial slices, flip angle/TR/TE=90/2500ms/TE=50ms) obtained with a GE 1.5 T scanner were used to collect 120 blood oxygen level-dependent images from ten healthy volunteers performing the modified Stroop task. The imaging data were investigated to determine, firstly, the network used to solve the Stroop interference test with previously acquired information and, secondly, the neural correlates of the retrieval of the previously acquired information. Activation maps were acquired by means of the random effect model using SPM2. Results: More extensive regions, including the right middle frontal gyrus, right precuneus, left cerebellum, right supplement motor area, left insula, and left middle temporal and occipital gyri, were needed to solve the Stroop task with previously acquired information than to solve the Stroop-only task. The left precuneus and right superior temporal gyrus (STG) were among those regions which remained activated in the Stroop condition with previously acquired information after using the Stroop mask. Conclusions: This study demonstrated that the left precuneus and right STG are neuronal correlates of the retrieval of previously acquired information during top-down control. Further studies using connectivity analysis are needed to clarify the top-down control mechanism using previously acquired information.