Carrasco, M., McElree, B.,
Denisova, K., & Giordano, A.M. (2003). Speed of visual processing
increases with eccentricity. Nature Neuroscience , doi:10.1038/nn1079,
The visual system has a duplex design to meet conflicting environmental
demands: the fovea has the resolution required to process fine spatial
information, but the periphery is more sensitive to temporal properties1-3.
To investigate whether the periphery's sensitivity is partly due to the
speed with which information is processed, we measured the full timecourse
of visual information processing by deriving joint measures of discriminability
and speed, and found that speed of information processing varies with
eccentricity: processing was faster when same-size stimuli appeared at
9° than 4° eccentricity, and this difference was attenuated when the 9°
stimuli were magnified to equate cortical representation size. At the
same eccentricity, larger stimuli are processed more slowly. These temporal
differences are greater than expected from neurophysiological constraints4-6.