The precision of velocity discrimination across spatial frequency

被引:14
作者
Chen, Y
Bedell, HE [1 ]
Frishman, LJ
机构
[1] Univ Houston, Coll Optometry, Houston, TX 77024 USA
[2] Harvard Univ, Cambridge, MA 02138 USA
来源
PERCEPTION & PSYCHOPHYSICS | 1998年 / 60卷 / 08期
关键词
D O I
10.3758/BF03207995
中图分类号
B84 [心理学];
学科分类号
04 ; 0402 ;
摘要
The precision of velocity coding for moving stimuli of different spatial frequencies was assessed by measuring velocity discrimination thresholds for a 1-c/deg grating paired with a grating whose spatial frequency ranged from 0.25 to 4 c/deg and for grating pairs of the same spatial frequency (0.25, 1, and 4 c/deg). The gratings always moved upward, with velocities ranging from 0.5 to 16 deg/sec. Velocity discrimination was as precise for stimuli that varied in spatial frequency by +/-2 octaves (0.25 vs. I c/deg and 4 vs. 1 c/deg) as for stimuli of the same spatial frequency, for specific ranges of velocity that depended on the spatial and, therefore, the temporal frequencies of the stimuli. Compared with a 1-c/deg grating, the perceived velocity of 4-c/deg gratings was about 1.3 times faster and that of 0.25-c/deg gratings was about 1.3 times slower. Although these perceived velocity biases imply variation of velocity-signal processing among spatial frequency channels, the discrimination results indicate that the motion-sensing system can compare signals across different spatial frequency channels to make fine velocity discrimination within appropriate temporal frequency limits.
引用
收藏
页码:1329 / 1336
页数:8
相关论文
共 34 条