A common contrast pooling rule for suppression within and between the eyes

Area of Science:

• Vision science
• Neuroscience
• Psychophysics

Background:

• Cross-orientation suppression involves multiple visual pathways.
• Ipsiocular and interocular pathways influence vision before binocular summation.
• These pathways exhibit distinct spatial tuning, temporal dependencies, and adaptation after-effects.

Purpose of the Study:

• To investigate the rules for pooling multiple mask components within visual suppression pathways.
• To differentiate between spatial pooling and linear summation models of contrast gain control.
• To understand how monoptic, dichoptic, and binocular masking are processed.

Main Methods:

• Psychophysical contrast masking functions were measured for vertical gratings.
• Mask components outside the excitatory passband were used.
• Contrast gain control models with different pooling mechanisms were tested.

Main Results:

• Monoptic and dichoptic masking were best explained by spatial pooling models.
• Binocular masking required linear summation of Michelson contrast across orientations.
• Models involving suppressive pooling after compressive responses were invalidated.

Conclusions:

• Monoptic and dichoptic masking utilize similar contrast pooling within their suppressive fields.
• The effects from monoptic and dichoptic masking do not linearly sum to predict binocular masking.
• Visual processing employs distinct mechanisms for different masking conditions.