Cortical potentials evoked in humans by signals to perform memory-guided saccades

Increases in the latent periods of memory-guided saccades as compared with those of visually guided saccades were observed, providing evidence of slowing in saccade programming based on extraction of information from working memory. Comparison of the parameters and topography of the N1 and P1 components of evoked potentials induced by a signal to perform a memory-guided saccade and a visual stimulus-guided saccade suggested that the early stages of saccade programming, associated with the processing of spatial information, are mediated mainly by the descending mechanism of attention for memory-guided saccades and the ascending mechanism for saccades in response to a visual stimulus. These data may indicate that the increase in the latent period of memory-guided saccades is associated with lengthening of the central stage of saccade programming - the decision-taking stage, a correlate of which is the N2 wave developing in the middle of the latent period of the memory-guided saccade. The temporospatial dynamics of the N1, P1, and N2 components provide evidence that memory-guided saccade programming is controlled by the fronto-medio-thalamic system of selective attention, as well as by left-hemisphere motor attention mechanisms. © 2012 Springer Science+Business Media, Inc.