Antisaccades are rapid goal-directed eye movements requiring that a participant saccade mirror-symmetrical to the location of a target stimulus. Notably, antisaccades require top-down control and engage visual metrics that are distinct from their prosaccade counterparts. In keeping with this view, our group has shown that antisaccade endpoints are governed by a perceptual averaging strategy. In particular, endpoint bias for any target within a stimulus-set is influenced by the magnitude of the undershooting bias associated with the stimulus-set's central target. In other words, results suggest that antisaccade endpoints are influenced by relational target properties. To further address this issue, the present study examined whether the asymmetrical weighting of different target eccentricities within a stimulus-set systematically influences the direction (i.e., undershooting vs. overshooting) of antisaccade endpoint bias. To that end, participants (N=14) completed antisaccades (and matched prosaccades) to briefly presented target stimuli in three separate sessions. Target eccentricities in all sessions were 10.5, 15.5, and 20.5?°. In the first session (i.e. the control session) participants completed an equal number of trials to each target eccentricity, whereas in the other sessions participants respectively completed five times as many trials to the 10.5?° (i.e, proximal weighting condition) and 20.5?° (i.e., distal weighting condition) targets. Results for the control session showed that antisaccades across each target eccentricity elicited a reliable undershooting bias. Notably, however, for the proximal weighting condition it was found that antisaccade amplitudes produced an increased undershooting bias to all target eccentricities relative to their control condition counterparts. In turn, the distal weighting condition showed a reduced undershooting bias compared to their control condition counterparts. As such, we propose that the top-down nature of antisaccades elicits a perceptual averaging strategy that bias' a response in the direction of a frequently presented target stimulus.
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