The influence of illusory motion on line bisection performance in normal subjects.
The present study examines whether illusory movement (IM) of a horizontal line, induced by a moving background (MB), influences line-bisection performance in normal subjects. The first experiment attempted to identify the speeds of MB that induce IM. We found that when speed is increased from 1.53 degrees to 13.3 degrees/sec, IM increases, but that with further speed increases, IM decreases. Leftward MB induces rightward IM, and vice versa. In the second experiment, we had subjects bisect lines at MB speeds that had been shown to induce IM in the first experiment. We found that leftward MB induced a rightward bias, and vice versa. We also found that there was a relationship between the magnitude of IM and the degree of bias. In the third experiment, by making the target line larger than the MB, we made the conditions where IM was presumably absent. Unlike the results of bisection performed with IM, subjects showed a bias in the direction of the MB. Overall, these experiments demonstrated that the perception of motion induces subjects to attend in the direction of movement.
Choi
Kyung Mook
KM
Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Ku
Bon D
BD
Jeong
Yong
Y
Lee
Byung Hwa
BH
Ahn
Hyun-Jung
HJ
Kang
Sue J
SJ
Chin
Juhee
J
Heilman
Kenneth M
KM
Na
Duk L
DL
D000328:Adult; D005260:Female; D006801:Humans; D007088:Illusions / Q000502:physiology*; D008297:Male; D009038:Motion; D011597:Psychomotor Performance / Q000502:physiology*; D015203:Reproducibility of Results