Functional interactions between oculomotor regions during prosaccades and antisaccades

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Abstract
Human behavior reflects a continual negotiation of automatic and directed actions. The oculomotor network is a well‐characterized neural system in which to study this balance of behavioral control. For instance, saccades made toward and away from a flashed visual stimulus (prosaccades and antisaccades, respectively) are known to engage different cognitive processes. Brain regions important for such controlled execution include the presupplementary motor area (pre‐SMA), frontal eye fields (FEF), and intraparietal sulcus (IPS). Recent work has emphasized various elements of this network but has not explored the functional interactions among regions. We used event‐related fMRI to image human brain activity during performance of an interleaved pro/antisaccade task. Since traditional univariate statistics cannot address issues of functional connectivity, a multivariate technique is necessary. Coherence between fMRI time series of the pre‐SMA with the FEF and IPS was used to measure functional interactions. The FEF, but not IPS, showed significant differential coherence between pro‐ and antisaccade trials with pre‐SMA. These results suggest that the pre‐SMA coordinates with FEF to maintain a controlled, preparatory set for task‐appropriate oculomotor execution. Hum Brain Mapp, 2005.