Rapid motion aftereffect seen within uniform flickering test fields
Rapid motion aftereffect seen within uniform flickering test fields
复制标题
在均匀闪烁的测试场中看到快速运动后效应
作者：
M. Green;M. Chilcoat;C. Stromeyer
Prolonged viewing of a moving pattern selectively elevates the threshold for a pattern moving in the same direction1 and induces the classical motion aftereffect (MAE). The aftereffect is seen as a slow drift2 in the opposite direction, which is visible even with the eyes shut2,3 or while viewing a uniform field3,4. However, as we report here, a strikingly different aftereffect is seen when the test field is uniform and sinusoidally flickered: the field is filled with rapid motion in the direction opposite the adapting motion. This flicker MAE has distinct properties: the adapting grating must be of low spatial frequency; the effect is promoted by high contrast and high temporal frequencies of both adapting and test stimuli; and the aftereffect does not transfer interocularly. In all these respects the flicker MAE differs from the traditional MAE. Motion detectors have been identified in human vision by the threshold detectability5,6 and discriminability6 of moving patterns and by selective adaptation. The flicker MAE selectively taps a class of transient motion mechanisms that are selective for rapid motion and low spatial frequency. Uniform flicker is an effective stimulus for these mechanisms. It thus appears that the human visual system contains at least two distinct classes of mechanisms for sensing motion.
