Purchase this article with an account.
Nicole Spotswood, David Bressler, David Whitney; Visual motion area MT+ carries precise information about object position. Journal of Vision 2007;7(9):777. doi: 10.1167/7.9.777.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Single unit primate and human neuroimaging studies have reported that visual motion area MT+ displays selectivity for motion direction and coherence, and has receptive fields that are spatially localized. Despite this, previous results indicate that MT+ is only coarsely retinotopic. In an fMRI experiment we tested the precision of position coding in human area MT+ using a novel technique. For each of seven subjects, we defined an MT+ region of interest (ROI) by contrasting moving visual stimuli with a fixation baseline in a general linear model. Within these ROIs we cross-correlated activity patterns produced by flickering Gabors (i.e. Gabors with no direction of motion) in five slightly different positions, within a two degree window. When the Gabors were closely positioned, the patterns of activation in the MT+ ROIs were highly correlated. As the distance between the Gabors increased, the patterns of MT+ responses were able to reliably detect shifts in Gabor position of less than two degrees, at ten degrees eccentricity. The results suggest that MT+ carries precise topographic information about object position and may therefore play an important role in coding the position of moving objects.
This PDF is available to Subscribers Only