A 2ND-ORDER PATTERN REVEALS SEPARATE STRATEGIES FOR ENCODING ORIENTATION IN 2-DIMENSIONAL SPACE AND SPACE-TIME

We measured the perceived spatial orientation of the low contrast regi ons of contrast modulated sine gratings. Subjects make systematic erro rs which depend upon the carrier spatial frequency acid the angle betw een the carrier grating and the modulation. The results for the spatia l orientation task are compared with a motion domain analogue. The dif ference in the pattern of results for these two tasks suggests there e xist separate strategies for encoding orientation in two-dimensional s pace and space-time.