Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Up-down asymmetry in vertical induced motion

L A Lott1, R B Post

  • 1Department of Psychology, University of California, Davis 95616.

Perception
|January 1, 1993
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Spectral reflectivity measurements using fiber optics.

Applied optics·2010
Same author

Surface film thickness determination by reflectance measurements.

Applied optics·2010
Same author

Nonoperatively treated type A spinal fractures: mid-term versus long-term functional outcome.

International orthopaedics·2008
Same author

Return to work and quality of life in severely injured patients.

Disability and rehabilitation·2006
Same author

Functional outcome 5 years after non-operative treatment of type A spinal fractures.

European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society·2005
Same author

Sagittal range of motion after a spinal fracture: does ROM correlate with functional outcome?

European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society·2004

Induced motion (IM) is an illusion where objects appear to move oppositely to adjacent details. This study found IM magnitude was greater with upward motion, supporting the nystagmus-suppression theory.

Area of Science:

  • Visual perception
  • Neuroscience
  • Psychophysics

Background:

  • Induced motion (IM) is an illusory visual phenomenon where an object appears to move in the opposite direction of adjacent moving elements.
  • A leading theory suggests IM arises partly from the suppression of optokinetic nystagmus (OKN) during smooth-pursuit eye movements.
  • Previous research indicates an asymmetry in human vertical OKN, with upward motion yielding higher gain than downward motion.

Purpose of the Study:

  • To test the nystagmus-suppression theory of IM by investigating vertical IM magnitude under different stimulus motion directions and velocities.
  • To determine if the reported asymmetry in vertical OKN extends to the magnitude of vertical IM.
  • To examine how stimulus velocity influences the asymmetry of vertical IM.

Main Methods:

Related Experiment Videos

  • Twelve subjects participated in the study.
  • A large, random-dot stimulus was presented, moving either upward or downward at velocities of 10, 40, or 70 degrees per second.
  • Subjects performed a matching task, adjusting a rod to align with the perceived motion path of a fixated laser spot to quantify IM magnitude.

Main Results:

  • The mean velocity of induced motion was significantly greater for upward stimulus motion compared to downward motion.
  • This difference in IM magnitude between upward and downward stimulation was most pronounced at higher velocities (40 and 70 deg s-1).
  • The results demonstrate an asymmetry in vertical induced motion, consistent with predictions from the nystagmus-suppression theory.

Conclusions:

  • The findings support the nystagmus-suppression theory of induced motion, suggesting that the suppression of optokinetic nystagmus plays a significant role in generating the illusion.
  • The observed asymmetry in vertical IM, particularly at higher velocities, aligns with known asymmetries in vertical OKN.
  • Further research may explore the neural mechanisms underlying this directional asymmetry in visual motion perception.