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

On the perception of shape from shading.

D A Kleffner1, V S Ramachandran

  • 1Psychology Department, University of California, San Diego, La Jolla 92093-0109.

Perception & Psychophysics
|July 1, 1992
PubMed
Summary

Shape from shading is an early visual process, using assumptions like overhead lighting. This process influences grouping, search, and motion perception, suggesting specialized early visual neural elements.

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

Constructing calendars in the brain.

Neurocase·2019
Same author

Teaching Video NeuroImages: Mirror therapy against phantom pain.

Neurology·2019
Same author

Palilalia due to steroid-responsive encephalopathy.

Neurology. Clinical practice·2018
Same author

Synesthesia and the McCollough Effect.

i-Perception·2017
Same author

Hypothesis concerning embodied calendars: A case study of number form, color spreading, and taste-color synaesthesia.

Medical hypotheses·2016
Same author

Synesthetic colors induced by graphemes that have not been consciously perceived.

Neurocase·2014

Area of Science:

  • Visual Perception
  • Computational Neuroscience
  • Psychophysics

Background:

  • Shape from shading is a key aspect of visual perception.
  • Understanding its interaction with other visual processes is crucial.

Purpose of the Study:

  • Investigate how shape from shading interacts with perceptual grouping, search, and motion perception.
  • Determine the underlying assumptions and processing order of shape from shading.

Main Methods:

  • Conducted psychophysical experiments involving visual search and perception tasks.
  • Manipulated shading cues, luminance polarity, and display complexity.
  • Assessed reaction times and detection accuracy for convex and concave shapes.

Main Results:

  • Shape from shading relies on assumptions of single, overhead light sources.
  • Shading defines tokens for perceptual grouping and segregation.
  • A 'pop-out' effect for convex shapes is driven by shading, not luminance.
  • Naive observers show asymmetry in detecting cavities versus convex shapes.
  • Shape from shading influences motion perception and relies on retinal, not gravitational, coordinates.

Conclusions:

  • Shape from shading is an early visual process preceding grouping and motion perception.
  • Findings suggest specialized neural elements for shape from shading extraction.
  • Overhead illumination assumption is critical for grouping and relies on retinal coordinates.

Related Experiment Videos