The lowering of the apparent number of components in repeated patterns is known as redundancy masking. It has a lot of traits with crowding, which is defined as the inability to identify a goal in a cluttered environment. The position of the target in the visual field had a big impact on crowding. It is, for example, greater in the upper visual field than in the lower, and it is generally weakest on the horizontal meridian. As demonstrated by tasks testing spatial resolution and contrast sensitivity, the pattern of visual field asymmetries is ubiquitous in spatial vision. Researchers studied if redundancy masking exhibited the same typical visual field asymmetries as other spatial tasks in order to describe it and expose its similarities and differences from other spatial tasks. About three to six radially oriented lines at 10° eccentricity were given to observers at one of eight places surrounding fixation, and they were asked to indicate the number of lines. They discovered inequalities that were much different from those reported in crowding. There was no difference in redundancy masking between the upper and lower visual fields. Importantly, redundancy masking was stronger on the horizontal meridian than on the vertical meridian, which is the polar opposite of crowding. The findings revealed that redundancy masking differed from crowding in terms of visual field asymmetries, implying that redundancy masking and crowding have separate underlying processes.
The observed anomalous visual field asymmetries in redundancy masking were thought to be attributable to greater regularity extraction and a more significant compression of visual space on the horizontal meridian compared to the vertical meridian.