Inhibiroty effects in the detection of 1 cpd jo targets superimposed to angular frequency stimuli or sinewave gratings

ABSTRACT

Independence among channels processing different aspects of spatial information, including orthogonal stimuli, has beens generally assumed in the literature. We tested independence between the processing of j(o) targets and the processing of either vertical sinosoidal gratings or angular frequency stimuli with suprathreshold summation. We found the detection of a j(o) target at 1 cpd to be affected in an inhibitory fashion by either background angular frequencies in the range of 3-96 cycles or sinewave gratings in the range of 0.8-3.0 cpd. These results demonstrate interactions both among orthogonal stimuli and among channels processing vertical sinewave gratings and j(o) target stimuli. Our discussion focuses on the hypothesis of frequency decomposition in polar coordinates.