Electrophysiological Recordings in Humans Reveal Reduced Location-specific 3 Attentional-shift Activity Prior to Re-centering Saccades 4 5 6

32 Being able to effectively explore the visual world is of fundamental importance, and it has 33 been suggested that the straight-ahead gaze position within the egocentric reference frame 34 (“primary position”) might play a special role in this context. In the current study we 35 employed human electroencephalography (EEG) to examine neural activity related to the 36 spatial guidance of saccadic eye movements. Moreover, we sought to investigate whether 37 such activity would be modulated by the spatial relation of saccade direction to the primary 38 gaze position (re-centering saccades). Participants executed endogenously cued saccades 39 between five equidistant locations along the horizontal meridian. This design allowed for the 40 comparison of iso-amplitude saccades from the same starting position that were oriented 41 either towards the primary position (centripetal) or further away from it (centrifugal). By 42 back-averaging time-locked to the saccade onset on each trial, we identified a parietally 43 distributed, negative-polarity EEG deflection contralateral to the direction of the upcoming 44 saccade. Importantly, this contralateral pre-saccadic negativity, which appeared to reflect the 45 location-specific attentional guidance of the eye movement, was attenuated for re-centering 46 saccades relative to iso-amplitude centrifugal saccades. This differential electrophysiological 47 signature was paralleled by faster saccadic reaction times, and was substantially more 48 apparent when time-locking the data to the onset of the saccade rather than to the onset of the 49 cue, suggesting a tight temporal association with saccade initiation. The diminished level of 50 this pre-saccadic component for re-centering saccades may reflect the preferential coding of 51 the straight-ahead gaze position, in which both the eye-centered and head-centered reference 52 frames are perfectly aligned and from which the visual world can be effectively explored. 53 54