Opponent hues in visual masking.

Temporal interactions among opponent and non-opponent hues were investigated in a visual masking paradigm in which both backward and forward temporal sequences were employed. Subjective confidence ratings rather than identification thresholds alone served as response indicators for masking sequences. Results indicate that in the backward sequence (test stimulus followed by masking stimulus) a greater masking effect occurred when the stimuli were of non-opponent hue pairs (red-yellow, red-blue, green-yellow, green-blue) than when compared with opponent hue pairs (red-green, yellow-blue). For the forward sequence (test stimulus preceded by masking stimulus) the masking effect was reduced when compared with the backward sequence. These findings appear to reflect the presumed temporal and spatial antagonistic qualities of opponent hue processes as postulated in the Hering model of color vision.