Abstract
Recent evidence suggests that during the preparation of saccadic eye movements, orientation information that defines the saccade target is anticipated in foveal vision. Here, we establish that foveal prediction is not limited to surface features but operates similarly for temporally modulated signals: Coherent motion within the saccade target region predictively alters foveal perception and causes characteristic, reflexive eye movement patterns. Human observers maintained fixation in the center of a projection screen while 8000 dots distributed across the entire display moved in random directions at a velocity of 15 degrees of visual angle per second (dva/s; 50 ms lifetime). Subsequently, all dots within a 3 dva diameter circular region located 10 dva to the left or right of the screen center started moving coherently straight up or down. Observers prepared a saccade to this target while monitoring the appearance of another coherent motion signal in their presaccadic center of gaze (the foveal probe; presented in 50% of trials). Around 150 ms after target onset, observers were better at detecting the foveal probe if its motion direction matched the motion direction of the target dots, mirroring previous findings obtained with orientation-defined stimuli. Moreover, 150 to 100 ms before the saccade and during the last 15 ms immediately preceding saccade onset, vertical eye velocities reflected the motion direction within the target region rather than foveally presented motion. This ramp-up altered saccade angles and persisted after saccade landing, long before postsaccadic visual input could have driven gaze behavior and even when we rendered coherent target motion incoherent upon saccade initiation. We conclude that foveal prediction supports visual continuity for surface features as well as temporally modulated information. Beyond influencing perception, the underlying predictive signals modify pre-, intra- and early postsaccadic gaze behavior and generate a continuous oculomotor readout of target anticipation.