Abstract
In order to optimize the uptake of visual information, humans need to transfer and integrate information across saccadic eye movements. Recently, it has been shown that pre- and post-saccadic information at the saccade target is integrated in a near-optimal manner (Ganmor, Landy, & Simoncelli, 2015; Wolf & Schütz, 2015). The spatial specificity of integration is unknown and there is divergent evidence as to whether related trans-saccadic processes such as pre-saccadic shifts of attention and predictive remapping of receptive fields are specific to the saccade target, or are widespread across the visual field. To test the spatial distribution of transsaccadic integration, participants had to execute horizontal saccades, and we measured integration performance at six locations across the visual field: at the saccade target, above the saccade target, beyond the saccade target, above and beyond the saccade target, in-between initial fixation and saccade target, and above initial fixation. Saccades were always made to the saccade target, while a randomly-oriented Gabor was presented predictably at one of the tested locations. The Gabors were presented either pre-saccadically, post-saccadically, or both (trans-saccadic trials), and participants used a free-rotation task to respond to the perceived orientation of the Gabor. Performance was measured as the smallest angular distance between the presented and reported stimulus orientation. Results showed that performance on trans-saccadic trials was better than pre- or post-saccadic performance alone, for all locations except for the location above initial fixation. This demonstrates that integration can occur across the visual field in the direction of the saccade: a spatial profile that reflects regions where remote distractor effects are most prominent. This suggests that in terms of integration, the saccade target may not receive preferential processing, and that transsaccadic integration may be a more general mechanism used to reconcile information across saccades for the whole visual field.
Acknowledgement: This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 676786).