Visual Angle - Angular Size Illusion and Area V1

Angular Size Illusion and Area V1

The Murray, et al. observers viewed a flat picture with two disks that subtended the same visual angle and formed retinal images of the same size, but the perceived angular size of one was about 17% larger than for the other, due to differences in the background patterns for the disks.

The major discovery was that the sizes of the area V1 activity patterns related to the disks were unequal, despite the fact that the retinal images were the same size. This size difference in area V1 correlated almost perfectly with the 17% illusory difference between the perceived visual angles.

These new findings are crucial for theories of visual space perception and especially any visual angle illusion.

Read more about this topic:  Visual Angle

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