TY - JOUR T1 - Faster than the brain’s speed of light: Retinocortical interactions differ in high frequency activity when processing darks and lights JF - bioRxiv DO - 10.1101/153551 SP - 153551 AU - Britta U. Westner AU - Sarang S. Dalal Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/06/21/153551.abstract N2 - Some studies suggest that the processing of darks benefits from greater neural resources in the visual system and potentially occurs faster. However, evidence from the human is still sparse, especially with respect to retinocortical interactions. We recorded retinal and cortical responses to 480 ms light flashes simultaneously with electroretinography (ERG) and magnetencephalography (MEG) in ten participants and analyzed the high frequency responses to the flash onsets and offsets.We show that high frequency oscillations for flash offsets occur earlier than flash onsets in the cortex but not in the retina. Interestingly, while the onset activity involved a wide range of frequencies (55–195 Hz in the retina, and 55–145 Hz in the cortex), the offset response was restricted to the 7595 Hz frequency band in both retina and cortex. The results suggest faster propagation times but not earlier retinal processing for darks than lights, suggesting a thalamic role. They also support previous findings that the retinal high frequency activity is transmitted to cortex. Furthermore, the outcomes add to the ongoing discussion about the function of narrowband oscillations in the human visual system. ER -