Cortical dynamics of externally and self-directed attention: a MEG study of a card sorting task

Introduction Neuroimaging studies using functional magnetic resonance imaging (fMRI) have revealed different neural networks within the frontal cortex dealing with the environment or with endogenous mental processes. Conclusions This card-sorting paradigm generates different attentional states depending on whether the subjects only have to focus their attention to the stimulus and to the current rule, or have furthermore to recall the two rules not presently used and to arbitrary choose one of them.