Stimuli used in the experiments. Because the second frame is spatially shifted by exactly a cycle from the first frame, we refer to it as the neutral-shift condition. In the latter two conditions the second frame is shifted in the specified direction by a quarter cycle. Magnitude of bias was defined as number of rightward responses minus number of leftward responses for each subject. Each bar indicates the mean of 8 subjects.
Negative scores indicate leftward bias.
The native language of the top two groups is English. Left side drivers are native Japanese whose first language reads left to right. The Japanese sample also provides a bilingual control in which both languages read left to right.