Saccade-synchronized alpha rhythms predict strength of memory trace of stimulus orientation
Chiara Terzo1, David C Burr2, Xin-Yu Xie3
1Department of Neuroscience, Psychology, Pharmacology, and Child Health, University of Florence, Florence, 50135, Italy.
Background:
Saccadic eye movements allow us to sample the world sequentially, but pose challenges to the visual system, which must integrate information across successive fixations. The mechanisms subserving the integration may share properties with "serial dependence," the assimilative bias caused by previous sensory experience on current perception.
Results:
We investigated serial dependence during saccadic eye movements by measuring ERP responses from participants during visually driven saccadic eye movements while they viewed a brief Gabor patch, presented at various orientations (± 35°, ± 45°, or ± 55°), and then reproduced its orientation. Our findings demonstrate that both alpha and beta oscillations are synchronized by the saccades. Importantly, we found that the strength of alpha oscillations correlates (negatively) with the magnitude of serial dependence, particular in the right parietal cortex, while that of beta oscillations does not.
Conclusions:
These results provide evidence that pre-saccadic alpha oscillations contain information to be carried across saccades, probably fundamental for integration of visual information across saccades, and trans-saccadic perceptual stability.
