Our group will be presenting a couple of posters at this year’s Society for Neuroscience conference. Do swing by the posters if you get the chance!
One poster we will be presenting is on our work with orientation probability. We have constantly found that probable tilts are represented more precisely than improbable ones. Our hypothesis has been that exposure to such probablistic infomation tunes the relevant perceptual processing neurons, which in this case, would be the orientation-selective V1 neurons. Consistent with the hypothesis, we demonstrate that orienation probability robustly modulates ‘C1’, an early (90-100ms peak) ERP component which has been source-localized to the calcarine cortex. This activity correlates to the decisional ‘P3’ component, without modulating the ‘attentional’ ‘P1’ and ‘N1’ components. Thus, orientation probability effects likely are not the result of ‘top-down’ attentional mechanisms, but rather, reflect localised changes in early perception.