When dissimilar images are presented to the two eyes, binocular rivalry (BR) occurs, and perception alternates spontaneously between the images. Although neural correlates of the oscillating perception during BR have been found in multiple sites along the visual pathway, the source of BR dynamics is unclear. Psychophysical and modeling studies suggest that both low- and high-level cortical processes underlie BR dynamics. Previous neuroimaging studies have demonstrated the involvement of high-level regions by showing that frontal and parietal cortices responded time locked (...) to spontaneous perceptual alternation in BR. However, a potential contribution of early visual areas to BR dynamics has been overlooked, because these areas also responded to the physical stimulus alternation mimicking BR. In the present study, instead of focusing on activity during perceptual switches, we highlighted brain activity during suppression periods to investigate a potential link between activity in human early visual areas and BR dynamics. We used a strong interocular suppression paradigm called continuous flash suppression to suppress and fluctuate the visibility of a probe stimulus and measured retinotopic responses to the onset of the invisible probe using functional MRI. There were ∼130-fold differences in the median suppression durations across 12 subjects. The individual differences in suppression durations could be predicted by the amplitudes of the retinotopic activity in extrastriate visual areas (V3 and V4v) evoked by the invisible probe. Weaker responses were associated with longer suppression durations. These results demonstrate that retinotopic representations in early visual areas play a role in the dynamics of perceptual alternations during BR. (shrink)

Ang papel ay paglalagom ng itinuturing na pinakamahalagang yugto ng buhay ni José Rizal—ang kanyang pagkakatapon sa Dapitan, sa lente ng konseptong “bagani” ng ating mga ninuno. Sa pagbanggit sa lang nauna nang pag-aaral ukol kay Rizal, ipapakitang kung papaanong ang yugto sa Dapitan ay ang katuparan ng kanyang mga layunin sa La Liga Filipina, na kanyang isinabuhay kasama ang bayan. Sa lente ng kasalukuyang pandemyang COVID 19, makikita natin na tila naranasan din ni Rizal sa kanyang pagkakatapon ang ilang (...) bagay na ating dinaranas ngayon, na tila siya isang frontliner na nasa lockdown, inilagay sa kuwarentena, nag-homeschooling, nagkaroon ng lockdown sickness at namahagi ng ayudang pangkabuhayan sa mga mamamayan ng isang natutulog na bayan upang ito ay sumiglang muli. Nawa ay maging inspirasyon sa bayan na anuman ang hamon at mga balakid, walang makapipigil sa isang Pilipino na magsilbi sa bayan gamit ang kanyang mga talento at manatiling liwanag ng katotohanan at kaalaman. (shrink)