The effect of past trials on perceived direction of motion in ambiguous motion quartets: temporal pattern detection, not priming

Abstract

In a motion quartet (MQ), two disks that fall at the endpoints of a diameter of an invisible circle are briefly presented and then replaced by two disks that fall on a second diameter. With proper choice of timing, the observer sees apparent rotation of the first pair into the second. When the angle between the diameters is about 90 deg, the direction of perceived rotation is ambiguous, half the time clockwise (C) and half counterclockwise Grant EY08266 from the National Institutes of Health; Grant RG0109/1999-B from the Human Frontiers Science Program; Grant SP67/6–2 from the Deutsche Forschungsgemeinschaft; Guest professorship at the University of Freiburg (LTM)